Add OMAP SSI driver to the HSI subsystem. The Synchronous Serial Interface (SSI) is a legacy version of HSI. As in the case of HSI, it is mainly used to connect Application engines (APE) with cellular modem engines (CMT) in cellular handsets. It provides a multichannel, full-duplex, multi-core communication with no reference clock. The OMAP SSI block is capable of reaching speeds of 110 Mbit/s. Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx> --- drivers/hsi/Kconfig | 1 + drivers/hsi/Makefile | 1 + drivers/hsi/controllers/Kconfig | 19 + drivers/hsi/controllers/Makefile | 6 + drivers/hsi/controllers/omap_ssi.c | 618 ++++++++++++++ drivers/hsi/controllers/omap_ssi.h | 166 ++++ drivers/hsi/controllers/omap_ssi_port.c | 1401 +++++++++++++++++++++++++++++++ drivers/hsi/controllers/omap_ssi_regs.h | 171 ++++ 8 files changed, 2383 insertions(+) create mode 100644 drivers/hsi/controllers/Kconfig create mode 100644 drivers/hsi/controllers/Makefile create mode 100644 drivers/hsi/controllers/omap_ssi.c create mode 100644 drivers/hsi/controllers/omap_ssi.h create mode 100644 drivers/hsi/controllers/omap_ssi_port.c create mode 100644 drivers/hsi/controllers/omap_ssi_regs.h diff --git a/drivers/hsi/Kconfig b/drivers/hsi/Kconfig index d94e38d..2c76de4 100644 --- a/drivers/hsi/Kconfig +++ b/drivers/hsi/Kconfig @@ -14,6 +14,7 @@ config HSI_BOARDINFO bool default y +source "drivers/hsi/controllers/Kconfig" source "drivers/hsi/clients/Kconfig" endif # HSI diff --git a/drivers/hsi/Makefile b/drivers/hsi/Makefile index 9d5d33f..360371e 100644 --- a/drivers/hsi/Makefile +++ b/drivers/hsi/Makefile @@ -3,4 +3,5 @@ # obj-$(CONFIG_HSI_BOARDINFO) += hsi_boardinfo.o obj-$(CONFIG_HSI) += hsi.o +obj-y += controllers/ obj-y += clients/ diff --git a/drivers/hsi/controllers/Kconfig b/drivers/hsi/controllers/Kconfig new file mode 100644 index 0000000..037a344 --- /dev/null +++ b/drivers/hsi/controllers/Kconfig @@ -0,0 +1,19 @@ +# +# HSI controllers configuration +# +comment "HSI controllers" + +config OMAP_SSI + tristate "OMAP SSI hardware driver" + depends on ARCH_OMAP && HSI + ---help--- + SSI is a legacy version of HSI. It is usually used to connect + an application engine with a cellular modem. + If you say Y here, you will enable the OMAP SSI hardware driver. + + If unsure, say N. + +config OMAP_SSI_PORT + tristate + default m if OMAP_SSI=m + default y if OMAP_SSI=y diff --git a/drivers/hsi/controllers/Makefile b/drivers/hsi/controllers/Makefile new file mode 100644 index 0000000..d2665cf --- /dev/null +++ b/drivers/hsi/controllers/Makefile @@ -0,0 +1,6 @@ +# +# Makefile for HSI controllers drivers +# + +obj-$(CONFIG_OMAP_SSI) += omap_ssi.o +obj-$(CONFIG_OMAP_SSI_PORT) += omap_ssi_port.o diff --git a/drivers/hsi/controllers/omap_ssi.c b/drivers/hsi/controllers/omap_ssi.c new file mode 100644 index 0000000..55ef01b --- /dev/null +++ b/drivers/hsi/controllers/omap_ssi.c @@ -0,0 +1,618 @@ +/* OMAP SSI driver. + * + * Copyright (C) 2010 Nokia Corporation. All rights reserved. + * Copyright (C) 2013 Sebastian Reichel <sre@xxxxxxxxxx> + * + * Contact: Carlos Chinea <carlos.chinea@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#include <linux/compiler.h> +#include <linux/err.h> +#include <linux/ioport.h> +#include <linux/io.h> +#include <linux/gpio.h> +#include <linux/clk.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/delay.h> +#include <linux/seq_file.h> +#include <linux/scatterlist.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/debugfs.h> +#include <linux/pm_runtime.h> +#include <linux/of_platform.h> +#include <linux/hsi/hsi.h> +#include <linux/idr.h> + +#include "omap_ssi_regs.h" +#include "omap_ssi.h" + +/* For automatically allocated device IDs */ +static DEFINE_IDA(platform_omap_ssi_ida); + +#ifdef CONFIG_DEBUG_FS +static int ssi_debug_show(struct seq_file *m, void *p __maybe_unused) +{ + struct hsi_controller *ssi = m->private; + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + void __iomem *sys = omap_ssi->sys; + + pm_runtime_get_sync(ssi->device.parent); + seq_printf(m, "REVISION\t: 0x%08x\n", readl(sys + SSI_REVISION_REG)); + seq_printf(m, "SYSCONFIG\t: 0x%08x\n", readl(sys + SSI_SYSCONFIG_REG)); + seq_printf(m, "SYSSTATUS\t: 0x%08x\n", readl(sys + SSI_SYSSTATUS_REG)); + pm_runtime_put_sync(ssi->device.parent); + + return 0; +} + +static int ssi_debug_gdd_show(struct seq_file *m, void *p __maybe_unused) +{ + struct hsi_controller *ssi = m->private; + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + void __iomem *gdd = omap_ssi->gdd; + void __iomem *sys = omap_ssi->sys; + int lch; + + pm_runtime_get_sync(ssi->device.parent); + + seq_printf(m, "GDD_MPU_STATUS\t: 0x%08x\n", + readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG)); + seq_printf(m, "GDD_MPU_ENABLE\t: 0x%08x\n\n", + readl(sys + SSI_GDD_MPU_IRQ_ENABLE_REG)); + seq_printf(m, "HW_ID\t\t: 0x%08x\n", + readl(gdd + SSI_GDD_HW_ID_REG)); + seq_printf(m, "PPORT_ID\t: 0x%08x\n", + readl(gdd + SSI_GDD_PPORT_ID_REG)); + seq_printf(m, "MPORT_ID\t: 0x%08x\n", + readl(gdd + SSI_GDD_MPORT_ID_REG)); + seq_printf(m, "TEST\t\t: 0x%08x\n", + readl(gdd + SSI_GDD_TEST_REG)); + seq_printf(m, "GCR\t\t: 0x%08x\n", + readl(gdd + SSI_GDD_GCR_REG)); + + for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++) { + seq_printf(m, "\nGDD LCH %d\n=========\n", lch); + seq_printf(m, "CSDP\t\t: 0x%04x\n", + readw(gdd + SSI_GDD_CSDP_REG(lch))); + seq_printf(m, "CCR\t\t: 0x%04x\n", + readw(gdd + SSI_GDD_CCR_REG(lch))); + seq_printf(m, "CICR\t\t: 0x%04x\n", + readw(gdd + SSI_GDD_CICR_REG(lch))); + seq_printf(m, "CSR\t\t: 0x%04x\n", + readw(gdd + SSI_GDD_CSR_REG(lch))); + seq_printf(m, "CSSA\t\t: 0x%08x\n", + readl(gdd + SSI_GDD_CSSA_REG(lch))); + seq_printf(m, "CDSA\t\t: 0x%08x\n", + readl(gdd + SSI_GDD_CDSA_REG(lch))); + seq_printf(m, "CEN\t\t: 0x%04x\n", + readw(gdd + SSI_GDD_CEN_REG(lch))); + seq_printf(m, "CSAC\t\t: 0x%04x\n", + readw(gdd + SSI_GDD_CSAC_REG(lch))); + seq_printf(m, "CDAC\t\t: 0x%04x\n", + readw(gdd + SSI_GDD_CDAC_REG(lch))); + seq_printf(m, "CLNK_CTRL\t: 0x%04x\n", + readw(gdd + SSI_GDD_CLNK_CTRL_REG(lch))); + } + + pm_runtime_put_sync(ssi->device.parent); + + return 0; +} + +static int ssi_regs_open(struct inode *inode, struct file *file) +{ + return single_open(file, ssi_debug_show, inode->i_private); +} + +static int ssi_gdd_regs_open(struct inode *inode, struct file *file) +{ + return single_open(file, ssi_debug_gdd_show, inode->i_private); +} + +static const struct file_operations ssi_regs_fops = { + .open = ssi_regs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static const struct file_operations ssi_gdd_regs_fops = { + .open = ssi_gdd_regs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init ssi_debug_add_ctrl(struct hsi_controller *ssi) +{ + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + struct dentry *dir; + + /* SSI controller */ + omap_ssi->dir = debugfs_create_dir(dev_name(&ssi->device), NULL); + if (IS_ERR(omap_ssi->dir)) + return PTR_ERR(omap_ssi->dir); + + debugfs_create_file("regs", S_IRUGO, omap_ssi->dir, ssi, + &ssi_regs_fops); + /* SSI GDD (DMA) */ + dir = debugfs_create_dir("gdd", omap_ssi->dir); + if (IS_ERR(dir)) + goto rback; + debugfs_create_file("regs", S_IRUGO, dir, ssi, &ssi_gdd_regs_fops); + + return 0; +rback: + debugfs_remove_recursive(omap_ssi->dir); + + return PTR_ERR(dir); +} + +static void ssi_debug_remove_ctrl(struct hsi_controller *ssi) +{ + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + debugfs_remove_recursive(omap_ssi->dir); +} +#endif /* CONFIG_DEBUG_FS */ + +/* + * FIXME: Horrible HACK needed until we remove the useless wakeline test + * in the CMT. To be removed !!!! + */ +void ssi_waketest(struct hsi_client *cl, unsigned int enable) +{ + struct hsi_port *port = hsi_get_port(cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + omap_port->wktest = !!enable; + if (omap_port->wktest) { + pm_runtime_get_sync(ssi->device.parent); + writel_relaxed(SSI_WAKE(0), + omap_ssi->sys + SSI_SET_WAKE_REG(port->num)); + } else { + writel_relaxed(SSI_WAKE(0), + omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num)); + pm_runtime_put_sync(ssi->device.parent); + } +} +EXPORT_SYMBOL_GPL(ssi_waketest); + +static void ssi_gdd_complete(struct hsi_controller *ssi, unsigned int lch) +{ + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + struct hsi_msg *msg = omap_ssi->gdd_trn[lch].msg; + struct hsi_port *port = to_hsi_port(msg->cl->device.parent); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + unsigned int dir; + u32 csr; + u32 val; + + spin_lock(&omap_ssi->lock); + + val = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG); + val &= ~SSI_GDD_LCH(lch); + writel_relaxed(val, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG); + + if (msg->ttype == HSI_MSG_READ) { + dir = DMA_FROM_DEVICE; + val = SSI_DATAAVAILABLE(msg->channel); + pm_runtime_put_sync(ssi->device.parent); + } else { + dir = DMA_TO_DEVICE; + val = SSI_DATAACCEPT(msg->channel); + /* Keep clocks reference for write pio event */ + } + dma_unmap_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents, dir); + csr = readw(omap_ssi->gdd + SSI_GDD_CSR_REG(lch)); + omap_ssi->gdd_trn[lch].msg = NULL; /* release GDD lch */ + dev_dbg(&port->device, "DMA completed ch %d ttype %d\n", + msg->channel, msg->ttype); + spin_unlock(&omap_ssi->lock); + if (csr & SSI_CSR_TOUR) { /* Timeout error */ + msg->status = HSI_STATUS_ERROR; + msg->actual_len = 0; + spin_lock(&omap_port->lock); + list_del(&msg->link); /* Dequeue msg */ + spin_unlock(&omap_port->lock); + msg->complete(msg); + return; + } + spin_lock(&omap_port->lock); + val |= readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + writel_relaxed(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + spin_unlock(&omap_port->lock); + + msg->status = HSI_STATUS_COMPLETED; + msg->actual_len = sg_dma_len(msg->sgt.sgl); +} + +static void ssi_gdd_tasklet(unsigned long dev) +{ + struct hsi_controller *ssi = (struct hsi_controller *)dev; + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + void __iomem *sys = omap_ssi->sys; + unsigned int lch; + u32 status_reg; + + pm_runtime_get_sync(ssi->device.parent); + + status_reg = readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG); + for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++) { + if (status_reg & SSI_GDD_LCH(lch)) + ssi_gdd_complete(ssi, lch); + } + writel_relaxed(status_reg, sys + SSI_GDD_MPU_IRQ_STATUS_REG); + status_reg = readl(sys + SSI_GDD_MPU_IRQ_STATUS_REG); + + pm_runtime_put_sync(ssi->device.parent); + + if (status_reg) + tasklet_hi_schedule(&omap_ssi->gdd_tasklet); + else + enable_irq(omap_ssi->gdd_irq); + +} + +static irqreturn_t ssi_gdd_isr(int irq, void *ssi) +{ + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + tasklet_hi_schedule(&omap_ssi->gdd_tasklet); + disable_irq_nosync(irq); + + return IRQ_HANDLED; +} + +static unsigned long ssi_get_clk_rate(struct hsi_controller *ssi) +{ + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + unsigned long rate = clk_get_rate(omap_ssi->fck); + return rate; +} + +static int __init ssi_get_iomem(struct platform_device *pd, + const char *name, void __iomem **pbase, dma_addr_t *phy) +{ + struct resource *mem; + struct resource *ioarea; + void __iomem *base; + struct hsi_controller *ssi = platform_get_drvdata(pd); + + mem = platform_get_resource_byname(pd, IORESOURCE_MEM, name); + if (!mem) { + dev_err(&pd->dev, "IO memory region missing (%s)\n", name); + return -ENXIO; + } + ioarea = devm_request_mem_region(&ssi->device, mem->start, + resource_size(mem), dev_name(&pd->dev)); + if (!ioarea) { + dev_err(&pd->dev, "%s IO memory region request failed\n", + mem->name); + return -ENXIO; + } + base = devm_ioremap(&ssi->device, mem->start, resource_size(mem)); + if (!base) { + dev_err(&pd->dev, "%s IO remap failed\n", mem->name); + return -ENXIO; + } + *pbase = base; + + if (phy) + *phy = mem->start; + + return 0; +} + +static int __init ssi_add_controller(struct hsi_controller *ssi, + struct platform_device *pd) +{ + struct omap_ssi_controller *omap_ssi; + struct resource *irq; + int err; + + omap_ssi = devm_kzalloc(&ssi->device, sizeof(*omap_ssi), GFP_KERNEL); + if (!omap_ssi) { + dev_err(&pd->dev, "not enough memory for omap ssi\n"); + return -ENOMEM; + } + + ssi->id = ida_simple_get(&platform_omap_ssi_ida, 0, 0, GFP_KERNEL); + if (ssi->id < 0) { + err = ssi->id; + goto out_err; + } + + ssi->owner = THIS_MODULE; + ssi->device.parent = &pd->dev; + dev_set_name(&ssi->device, "ssi%d", ssi->id); + hsi_controller_set_drvdata(ssi, omap_ssi); + omap_ssi->dev = &ssi->device; + err = ssi_get_iomem(pd, "sys", &omap_ssi->sys, NULL); + if (err < 0) + goto out_err; + err = ssi_get_iomem(pd, "gdd", &omap_ssi->gdd, NULL); + if (err < 0) + goto out_err; + irq = platform_get_resource_byname(pd, IORESOURCE_IRQ, "gdd_mpu"); + if (!irq) { + dev_err(&pd->dev, "GDD IRQ resource missing\n"); + err = -ENXIO; + goto out_err; + } + omap_ssi->gdd_irq = irq->start; + tasklet_init(&omap_ssi->gdd_tasklet, ssi_gdd_tasklet, + (unsigned long)ssi); + err = devm_request_irq(&ssi->device, omap_ssi->gdd_irq, ssi_gdd_isr, + 0, irq->name, ssi); + if (err < 0) { + dev_err(&ssi->device, "Request GDD IRQ %d failed (%d)", + omap_ssi->gdd_irq, err); + goto out_err; + } + + omap_ssi->port = devm_kzalloc(&ssi->device, + sizeof(struct omap_ssi_port *) * ssi->num_ports, GFP_KERNEL); + if (!omap_ssi->port) { + err = -ENOMEM; + goto out_err; + } + + omap_ssi->fck = devm_clk_get(&ssi->device, "ssi_ssr_fck"); + if (IS_ERR(omap_ssi->fck)) { + dev_err(&pd->dev, "Could not acquire clock \"ssi_ssr_fck\": %li\n", + PTR_ERR(omap_ssi->fck)); + err = -ENODEV; + goto out_err; + } + + /* TODO: find register, which can be used to detect context loss */ + omap_ssi->get_loss = NULL; + + omap_ssi->max_speed = UINT_MAX; + spin_lock_init(&omap_ssi->lock); + err = hsi_register_controller(ssi); + + if (err < 0) + goto out_err; + + return 0; + +out_err: + ida_simple_remove(&platform_omap_ssi_ida, ssi->id); + return err; +} + +static int __init ssi_hw_init(struct hsi_controller *ssi) +{ + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + unsigned int i; + u32 val; + int err; + + err = pm_runtime_get_sync(ssi->device.parent); + if (err < 0) { + dev_err(&ssi->device, "runtime PM failed %d\n", err); + return err; + } + /* Reseting SSI controller */ + writel_relaxed(SSI_SOFTRESET, omap_ssi->sys + SSI_SYSCONFIG_REG); + val = readl(omap_ssi->sys + SSI_SYSSTATUS_REG); + for (i = 0; ((i < 20) && !(val & SSI_RESETDONE)); i++) { + msleep(20); + val = readl(omap_ssi->sys + SSI_SYSSTATUS_REG); + } + if (!(val & SSI_RESETDONE)) { + dev_err(&ssi->device, "SSI HW reset failed\n"); + pm_runtime_put_sync(ssi->device.parent); + return -EIO; + } + /* Reseting GDD */ + writel_relaxed(SSI_SWRESET, omap_ssi->gdd + SSI_GDD_GRST_REG); + /* Get FCK rate in KHz */ + omap_ssi->fck_rate = DIV_ROUND_CLOSEST(ssi_get_clk_rate(ssi), 1000); + dev_dbg(&ssi->device, "SSI fck rate %lu KHz\n", omap_ssi->fck_rate); + /* Set default PM settings */ + val = SSI_AUTOIDLE | SSI_SIDLEMODE_SMART | SSI_MIDLEMODE_SMART; + writel_relaxed(val, omap_ssi->sys + SSI_SYSCONFIG_REG); + omap_ssi->sysconfig = val; + writel_relaxed(SSI_CLK_AUTOGATING_ON, omap_ssi->sys + SSI_GDD_GCR_REG); + omap_ssi->gdd_gcr = SSI_CLK_AUTOGATING_ON; + pm_runtime_put_sync(ssi->device.parent); + + return 0; +} + +static void ssi_remove_controller(struct hsi_controller *ssi) +{ + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + int id = ssi->id; + tasklet_kill(&omap_ssi->gdd_tasklet); + hsi_unregister_controller(ssi); + ida_simple_remove(&platform_omap_ssi_ida, id); +} + +static inline int ssi_of_get_available_child_count(const struct device_node *np) +{ + struct device_node *child; + int num = 0; + + for_each_child_of_node(np, child) + if (of_device_is_available(child)) + num++; + + return num; +} + +static int __init ssi_probe(struct platform_device *pd) +{ + struct device_node *np = pd->dev.of_node; + struct hsi_controller *ssi; + int err; + int num_ports; + + if (!np) { + dev_err(&pd->dev, "missing device tree data\n"); + return -EINVAL; + } + + num_ports = ssi_of_get_available_child_count(np); + + ssi = hsi_alloc_controller(num_ports, GFP_KERNEL); + if (!ssi) { + dev_err(&pd->dev, "No memory for controller\n"); + return -ENOMEM; + } + + platform_set_drvdata(pd, ssi); + + err = ssi_add_controller(ssi, pd); + if (err < 0) + goto out1; + + pm_runtime_irq_safe(&pd->dev); + pm_runtime_enable(&pd->dev); + + err = ssi_hw_init(ssi); + if (err < 0) + goto out2; +#ifdef CONFIG_DEBUG_FS + err = ssi_debug_add_ctrl(ssi); + if (err < 0) + goto out2; +#endif + + err = of_platform_populate(pd->dev.of_node, NULL, NULL, &pd->dev); + if (err) { + dev_err(&pd->dev, "failed to create ssi controller ports (err=%d)\n", + err); + return -ENODEV; + } + + dev_info(&pd->dev, "ssi controller %d initialized (%d ports)!\n", + ssi->id, num_ports); + return err; +out2: + ssi_remove_controller(ssi); +out1: + platform_set_drvdata(pd, NULL); + pm_runtime_disable(&pd->dev); + + return err; +} + +static int __exit ssi_remove_ports(struct device *dev, void *c) +{ + struct platform_device *pdev = to_platform_device(dev); + + of_device_unregister(pdev); + + return 0; +} + +static int __exit ssi_remove(struct platform_device *pd) +{ + struct hsi_controller *ssi = platform_get_drvdata(pd); + +#ifdef CONFIG_DEBUG_FS + ssi_debug_remove_ctrl(ssi); +#endif + ssi_remove_controller(ssi); + platform_set_drvdata(pd, NULL); + + pm_runtime_disable(&pd->dev); + + /* cleanup of of_platform_populate() call */ + device_for_each_child(&pd->dev, NULL, ssi_remove_ports); + + return 0; +} + +#ifdef CONFIG_PM_RUNTIME +static int omap_ssi_runtime_suspend(struct device *dev) +{ + struct hsi_controller *ssi = dev_get_drvdata(dev); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + dev_dbg(dev, "runtime suspend!\n"); + + if (omap_ssi->get_loss) + omap_ssi->loss_count = + (*omap_ssi->get_loss)(ssi->device.parent); + + return 0; +} + +static int omap_ssi_runtime_resume(struct device *dev) +{ + struct hsi_controller *ssi = dev_get_drvdata(dev); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + dev_dbg(dev, "runtime resume!\n"); + + if ((omap_ssi->get_loss) && (omap_ssi->loss_count == + (*omap_ssi->get_loss)(ssi->device.parent))) + return 0; + + writel_relaxed(omap_ssi->gdd_gcr, omap_ssi->gdd + SSI_GDD_GCR_REG); + + return 0; +} + +static const struct dev_pm_ops omap_ssi_pm_ops = { + SET_RUNTIME_PM_OPS(omap_ssi_runtime_suspend, omap_ssi_runtime_resume, + NULL) +}; + +#define DEV_PM_OPS (&omap_ssi_pm_ops) +#else +#define DEV_PM_OPS NULL +#endif + +#ifdef CONFIG_OF +static const struct of_device_id omap_ssi_of_match[] = { + { .compatible = "ti,omap3-ssi", }, + {}, +}; +MODULE_DEVICE_TABLE(of, omap_ssi_of_match); +#else +#define omap_ssi_of_match NULL +#endif + +static struct platform_driver ssi_pdriver = { + .remove = __exit_p(ssi_remove), + .driver = { + .name = "omap_ssi", + .owner = THIS_MODULE, + .pm = DEV_PM_OPS, + .of_match_table = omap_ssi_of_match, + }, +}; + +module_platform_driver_probe(ssi_pdriver, ssi_probe); + +MODULE_ALIAS("platform:omap_ssi"); +MODULE_AUTHOR("Carlos Chinea <carlos.chinea@xxxxxxxxx>"); +MODULE_AUTHOR("Sebastian Reichel <sre@xxxxxxxxxx>"); +MODULE_DESCRIPTION("Synchronous Serial Interface Driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/hsi/controllers/omap_ssi.h b/drivers/hsi/controllers/omap_ssi.h new file mode 100644 index 0000000..9d05641 --- /dev/null +++ b/drivers/hsi/controllers/omap_ssi.h @@ -0,0 +1,166 @@ +/* OMAP SSI internal interface. + * + * Copyright (C) 2010 Nokia Corporation. All rights reserved. + * Copyright (C) 2013 Sebastian Reichel + * + * Contact: Carlos Chinea <carlos.chinea@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#ifndef __LINUX_HSI_OMAP_SSI_H__ +#define __LINUX_HSI_OMAP_SSI_H__ + +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/hsi/hsi.h> +#include <linux/gpio.h> +#include <linux/interrupt.h> +#include <linux/io.h> + +#define SSI_MAX_CHANNELS 8 +#define SSI_MAX_GDD_LCH 8 +#define SSI_BYTES_TO_FRAMES(x) ((((x) - 1) >> 2) + 1) + +/** + * struct omap_ssm_ctx - OMAP synchronous serial module (TX/RX) context + * @mode: Bit transmission mode + * @channels: Number of channels + * @framesize: Frame size in bits + * @timeout: RX frame timeout + * @divisor: TX divider + * @arb_mode: Arbitration mode for TX frame (Round robin, priority) + */ +struct omap_ssm_ctx { + u32 mode; + u32 channels; + u32 frame_size; + union { + u32 timeout; /* Rx Only */ + struct { + u32 arb_mode; + u32 divisor; + }; /* Tx only */ + }; +}; + +/** + * struct omap_ssi_port - OMAP SSI port data + * @dev: device associated to the port (HSI port) + * @pdev: platform device associated to the port + * @sst_dma: SSI transmitter physical base address + * @ssr_dma: SSI receiver physical base address + * @sst_base: SSI transmitter base address + * @ssr_base: SSI receiver base address + * @wk_lock: spin lock to serialize access to the wake lines + * @lock: Spin lock to serialize access to the SSI port + * @channels: Current number of channels configured (1,2,4 or 8) + * @txqueue: TX message queues + * @rxqueue: RX message queues + * @brkqueue: Queue of incoming HWBREAK requests (FRAME mode) + * @irq: IRQ number + * @wake_irq: IRQ number for incoming wake line (-1 if none) + * @wake_gpio: GPIO number for incoming wake line (-1 if none) + * @pio_tasklet: Bottom half for PIO transfers and events + * @wake_tasklet: Bottom half for incoming wake events + * @wkin_cken: Keep track of clock references due to the incoming wake line + * @wk_refcount: Reference count for output wake line + * @sys_mpu_enable: Context for the interrupt enable register for irq 0 + * @sst: Context for the synchronous serial transmitter + * @ssr: Context for the synchronous serial receiver + */ +struct omap_ssi_port { + struct device *dev; + struct device *pdev; + dma_addr_t sst_dma; + dma_addr_t ssr_dma; + void __iomem *sst_base; + void __iomem *ssr_base; + spinlock_t wk_lock; + spinlock_t lock; + unsigned int channels; + struct list_head txqueue[SSI_MAX_CHANNELS]; + struct list_head rxqueue[SSI_MAX_CHANNELS]; + struct list_head brkqueue; + unsigned int irq; + int wake_irq; + int wake_gpio; + struct tasklet_struct pio_tasklet; + struct tasklet_struct wake_tasklet; + bool wktest:1; /* FIXME: HACK to be removed */ + bool wkin_cken:1; /* Workaround */ + unsigned int wk_refcount; + /* OMAP SSI port context */ + u32 sys_mpu_enable; /* We use only one irq */ + struct omap_ssm_ctx sst; + struct omap_ssm_ctx ssr; + u32 loss_count; + u32 port_id; +#ifdef CONFIG_DEBUG_FS + struct dentry *dir; +#endif +}; + +/** + * struct gdd_trn - GDD transaction data + * @msg: Pointer to the HSI message being served + * @sg: Pointer to the current sg entry being served + */ +struct gdd_trn { + struct hsi_msg *msg; + struct scatterlist *sg; +}; + +/** + * struct omap_ssi_controller - OMAP SSI controller data + * @dev: device associated to the controller (HSI controller) + * @sys: SSI I/O base address + * @gdd: GDD I/O base address + * @fck: SSI functional clock + * @gdd_irq: IRQ line for GDD + * @gdd_tasklet: bottom half for DMA transfers + * @gdd_trn: Array of GDD transaction data for ongoing GDD transfers + * @lock: lock to serialize access to GDD + * @loss_count: To follow if we need to restore context or not + * @max_speed: Maximum TX speed (Kb/s) set by the clients. + * @sysconfig: SSI controller saved context + * @gdd_gcr: SSI GDD saved context + * @get_loss: Pointer to omap_pm_get_dev_context_loss_count, if any + * @port: Array of pointers of the ports of the controller + * @dir: Debugfs SSI root directory + */ +struct omap_ssi_controller { + struct device *dev; + void __iomem *sys; + void __iomem *gdd; + struct clk *fck; + unsigned int gdd_irq; + struct tasklet_struct gdd_tasklet; + struct gdd_trn gdd_trn[SSI_MAX_GDD_LCH]; + spinlock_t lock; + unsigned long fck_rate; + u32 loss_count; + u32 max_speed; + /* OMAP SSI Controller context */ + u32 sysconfig; + u32 gdd_gcr; + int (*get_loss)(struct device *dev); + struct omap_ssi_port **port; +#ifdef CONFIG_DEBUG_FS + struct dentry *dir; +#endif +}; + +#endif /* __LINUX_HSI_OMAP_SSI_H__ */ diff --git a/drivers/hsi/controllers/omap_ssi_port.c b/drivers/hsi/controllers/omap_ssi_port.c new file mode 100644 index 0000000..1ecae14 --- /dev/null +++ b/drivers/hsi/controllers/omap_ssi_port.c @@ -0,0 +1,1401 @@ +/* OMAP SSI port driver. + * + * Copyright (C) 2010 Nokia Corporation. All rights reserved. + * Copyright (C) 2013 Sebastian Reichel <sre@xxxxxxxxxx> + * + * Contact: Carlos Chinea <carlos.chinea@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#include <linux/platform_device.h> +#include <linux/dma-mapping.h> +#include <linux/pm_runtime.h> + +#include <linux/of_gpio.h> +#include <linux/debugfs.h> + +#include "omap_ssi_regs.h" +#include "omap_ssi.h" + +static inline int hsi_dummy_msg(struct hsi_msg *msg __maybe_unused) +{ + return 0; +} + +static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused) +{ + return 0; +} + +static inline unsigned int ssi_wakein(struct hsi_port *port) +{ + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + return gpio_get_value(omap_port->wake_gpio); +} + +#ifdef CONFIG_DEBUG_FS +static void ssi_debug_remove_port(struct hsi_port *port) +{ + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + + debugfs_remove_recursive(omap_port->dir); +} + +static int ssi_debug_port_show(struct seq_file *m, void *p __maybe_unused) +{ + struct hsi_port *port = m->private; + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + void __iomem *base = omap_ssi->sys; + unsigned int ch; + + pm_runtime_get_sync(omap_port->pdev); + if (omap_port->wake_irq > 0) + seq_printf(m, "CAWAKE\t\t: %d\n", ssi_wakein(port)); + seq_printf(m, "WAKE\t\t: 0x%08x\n", + readl(base + SSI_WAKE_REG(port->num))); + seq_printf(m, "MPU_ENABLE_IRQ%d\t: 0x%08x\n", 0, + readl(base + SSI_MPU_ENABLE_REG(port->num, 0))); + seq_printf(m, "MPU_STATUS_IRQ%d\t: 0x%08x\n", 0, + readl(base + SSI_MPU_STATUS_REG(port->num, 0))); + /* SST */ + base = omap_port->sst_base; + seq_puts(m, "\nSST\n===\n"); + seq_printf(m, "ID SST\t\t: 0x%08x\n", + readl(base + SSI_SST_ID_REG)); + seq_printf(m, "MODE\t\t: 0x%08x\n", + readl(base + SSI_SST_MODE_REG)); + seq_printf(m, "FRAMESIZE\t: 0x%08x\n", + readl(base + SSI_SST_FRAMESIZE_REG)); + seq_printf(m, "DIVISOR\t\t: 0x%08x\n", + readl(base + SSI_SST_DIVISOR_REG)); + seq_printf(m, "CHANNELS\t: 0x%08x\n", + readl(base + SSI_SST_CHANNELS_REG)); + seq_printf(m, "ARBMODE\t\t: 0x%08x\n", + readl(base + SSI_SST_ARBMODE_REG)); + seq_printf(m, "TXSTATE\t\t: 0x%08x\n", + readl(base + SSI_SST_TXSTATE_REG)); + seq_printf(m, "BUFSTATE\t: 0x%08x\n", + readl(base + SSI_SST_BUFSTATE_REG)); + seq_printf(m, "BREAK\t\t: 0x%08x\n", + readl(base + SSI_SST_BREAK_REG)); + for (ch = 0; ch < omap_port->channels; ch++) { + seq_printf(m, "BUFFER_CH%d\t: 0x%08x\n", ch, + readl(base + SSI_SST_BUFFER_CH_REG(ch))); + } + /* SSR */ + base = omap_port->ssr_base; + seq_puts(m, "\nSSR\n===\n"); + seq_printf(m, "ID SSR\t\t: 0x%08x\n", + readl(base + SSI_SSR_ID_REG)); + seq_printf(m, "MODE\t\t: 0x%08x\n", + readl(base + SSI_SSR_MODE_REG)); + seq_printf(m, "FRAMESIZE\t: 0x%08x\n", + readl(base + SSI_SSR_FRAMESIZE_REG)); + seq_printf(m, "CHANNELS\t: 0x%08x\n", + readl(base + SSI_SSR_CHANNELS_REG)); + seq_printf(m, "TIMEOUT\t\t: 0x%08x\n", + readl(base + SSI_SSR_TIMEOUT_REG)); + seq_printf(m, "RXSTATE\t\t: 0x%08x\n", + readl(base + SSI_SSR_RXSTATE_REG)); + seq_printf(m, "BUFSTATE\t: 0x%08x\n", + readl(base + SSI_SSR_BUFSTATE_REG)); + seq_printf(m, "BREAK\t\t: 0x%08x\n", + readl(base + SSI_SSR_BREAK_REG)); + seq_printf(m, "ERROR\t\t: 0x%08x\n", + readl(base + SSI_SSR_ERROR_REG)); + seq_printf(m, "ERRORACK\t: 0x%08x\n", + readl(base + SSI_SSR_ERRORACK_REG)); + for (ch = 0; ch < omap_port->channels; ch++) { + seq_printf(m, "BUFFER_CH%d\t: 0x%08x\n", ch, + readl(base + SSI_SSR_BUFFER_CH_REG(ch))); + } + pm_runtime_put_sync(omap_port->pdev); + + return 0; +} + +static int ssi_port_regs_open(struct inode *inode, struct file *file) +{ + return single_open(file, ssi_debug_port_show, inode->i_private); +} + +static const struct file_operations ssi_port_regs_fops = { + .open = ssi_port_regs_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int ssi_div_get(void *data, u64 *val) +{ + struct hsi_port *port = data; + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + + pm_runtime_get_sync(omap_port->pdev); + *val = readl(omap_port->sst_base + SSI_SST_DIVISOR_REG); + pm_runtime_put_sync(omap_port->pdev); + + return 0; +} + +static int ssi_div_set(void *data, u64 val) +{ + struct hsi_port *port = data; + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + + if (val > 127) + return -EINVAL; + + pm_runtime_get_sync(omap_port->pdev); + writel(val, omap_port->sst_base + SSI_SST_DIVISOR_REG); + omap_port->sst.divisor = val; + pm_runtime_put_sync(omap_port->pdev); + + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(ssi_sst_div_fops, ssi_div_get, ssi_div_set, "%llu\n"); + +static int __init ssi_debug_add_port(struct omap_ssi_port *omap_port, + struct dentry *dir) +{ + struct hsi_port *port = to_hsi_port(omap_port->dev); + + dir = debugfs_create_dir(dev_name(omap_port->dev), dir); + if (IS_ERR(dir)) + return PTR_ERR(dir); + omap_port->dir = dir; + debugfs_create_file("regs", S_IRUGO, dir, port, &ssi_port_regs_fops); + dir = debugfs_create_dir("sst", dir); + if (IS_ERR(dir)) + return PTR_ERR(dir); + debugfs_create_file("divisor", S_IRUGO | S_IWUSR, dir, port, + &ssi_sst_div_fops); + + return 0; +} +#endif + +static int ssi_claim_lch(struct hsi_msg *msg) +{ + + struct hsi_port *port = hsi_get_port(msg->cl); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + int lch; + + for (lch = 0; lch < SSI_MAX_GDD_LCH; lch++) + if (!omap_ssi->gdd_trn[lch].msg) { + omap_ssi->gdd_trn[lch].msg = msg; + omap_ssi->gdd_trn[lch].sg = msg->sgt.sgl; + return lch; + } + + return -EBUSY; +} + +static int ssi_start_dma(struct hsi_msg *msg, int lch) +{ + struct hsi_port *port = hsi_get_port(msg->cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + void __iomem *gdd = omap_ssi->gdd; + int err; + u16 csdp; + u16 ccr; + u32 s_addr; + u32 d_addr; + u32 tmp; + + if (msg->ttype == HSI_MSG_READ) { + err = dma_map_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents, + DMA_FROM_DEVICE); + if (err < 0) { + dev_dbg(&ssi->device, "DMA map SG failed !\n"); + return err; + } + csdp = SSI_DST_BURST_4x32_BIT | SSI_DST_MEMORY_PORT | + SSI_SRC_SINGLE_ACCESS0 | SSI_SRC_PERIPHERAL_PORT | + SSI_DATA_TYPE_S32; + ccr = msg->channel + 0x10 + (port->num * 8); /* Sync */ + ccr |= SSI_DST_AMODE_POSTINC | SSI_SRC_AMODE_CONST | + SSI_CCR_ENABLE; + s_addr = omap_port->ssr_dma + + SSI_SSR_BUFFER_CH_REG(msg->channel); + d_addr = sg_dma_address(msg->sgt.sgl); + } else { + err = dma_map_sg(&ssi->device, msg->sgt.sgl, msg->sgt.nents, + DMA_TO_DEVICE); + if (err < 0) { + dev_dbg(&ssi->device, "DMA map SG failed !\n"); + return err; + } + csdp = SSI_SRC_BURST_4x32_BIT | SSI_SRC_MEMORY_PORT | + SSI_DST_SINGLE_ACCESS0 | SSI_DST_PERIPHERAL_PORT | + SSI_DATA_TYPE_S32; + ccr = (msg->channel + 1 + (port->num * 8)) & 0xf; /* Sync */ + ccr |= SSI_SRC_AMODE_POSTINC | SSI_DST_AMODE_CONST | + SSI_CCR_ENABLE; + s_addr = sg_dma_address(msg->sgt.sgl); + d_addr = omap_port->sst_dma + + SSI_SST_BUFFER_CH_REG(msg->channel); + } + dev_dbg(&ssi->device, "lch %d cdsp %08x ccr %04x s_addr %08x d_addr %08x\n", + lch, csdp, ccr, s_addr, d_addr); + + /* Hold clocks during the transfer */ + pm_runtime_get_sync(omap_port->pdev); + + writew_relaxed(csdp, gdd + SSI_GDD_CSDP_REG(lch)); + writew_relaxed(SSI_BLOCK_IE | SSI_TOUT_IE, gdd + SSI_GDD_CICR_REG(lch)); + writel_relaxed(d_addr, gdd + SSI_GDD_CDSA_REG(lch)); + writel_relaxed(s_addr, gdd + SSI_GDD_CSSA_REG(lch)); + writew_relaxed(SSI_BYTES_TO_FRAMES(msg->sgt.sgl->length), + gdd + SSI_GDD_CEN_REG(lch)); + + spin_lock_bh(&omap_ssi->lock); + tmp = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG); + tmp |= SSI_GDD_LCH(lch); + writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG); + spin_unlock_bh(&omap_ssi->lock); + writew(ccr, gdd + SSI_GDD_CCR_REG(lch)); + msg->status = HSI_STATUS_PROCEEDING; + + return 0; +} + +static int ssi_start_pio(struct hsi_msg *msg) +{ + struct hsi_port *port = hsi_get_port(msg->cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + u32 val; + + pm_runtime_get_sync(omap_port->pdev); + if (msg->ttype == HSI_MSG_WRITE) { + val = SSI_DATAACCEPT(msg->channel); + /* Hold clocks for pio writes */ + pm_runtime_get_sync(omap_port->pdev); + } else { + val = SSI_DATAAVAILABLE(msg->channel) | SSI_ERROROCCURED; + } + dev_dbg(&port->device, "Single %s transfer\n", + msg->ttype ? "write" : "read"); + val |= readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + writel(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + pm_runtime_put_sync(omap_port->pdev); + msg->actual_len = 0; + msg->status = HSI_STATUS_PROCEEDING; + + return 0; +} + +static int ssi_start_transfer(struct list_head *queue) +{ + struct hsi_msg *msg; + int lch = -1; + + if (list_empty(queue)) + return 0; + msg = list_first_entry(queue, struct hsi_msg, link); + if (msg->status != HSI_STATUS_QUEUED) + return 0; + if ((msg->sgt.nents) && (msg->sgt.sgl->length > sizeof(u32))) + lch = ssi_claim_lch(msg); + if (lch >= 0) + return ssi_start_dma(msg, lch); + else + return ssi_start_pio(msg); +} + +static int ssi_async_break(struct hsi_msg *msg) +{ + struct hsi_port *port = hsi_get_port(msg->cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + int err = 0; + u32 tmp; + + pm_runtime_get_sync(omap_port->pdev); + if (msg->ttype == HSI_MSG_WRITE) { + if (omap_port->sst.mode != SSI_MODE_FRAME) { + err = -EINVAL; + goto out; + } + writel(1, omap_port->sst_base + SSI_SST_BREAK_REG); + msg->status = HSI_STATUS_COMPLETED; + msg->complete(msg); + } else { + if (omap_port->ssr.mode != SSI_MODE_FRAME) { + err = -EINVAL; + goto out; + } + spin_lock_bh(&omap_port->lock); + tmp = readl(omap_ssi->sys + + SSI_MPU_ENABLE_REG(port->num, 0)); + writel(tmp | SSI_BREAKDETECTED, + omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + msg->status = HSI_STATUS_PROCEEDING; + list_add_tail(&msg->link, &omap_port->brkqueue); + spin_unlock_bh(&omap_port->lock); + } +out: + pm_runtime_put_sync(omap_port->pdev); + + return err; +} + +static int ssi_async(struct hsi_msg *msg) +{ + struct hsi_port *port = hsi_get_port(msg->cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct list_head *queue; + int err = 0; + + BUG_ON(!msg); + + if (msg->sgt.nents > 1) + return -ENOSYS; /* TODO: Add sg support */ + + if (msg->break_frame) + return ssi_async_break(msg); + + if (msg->ttype) { + BUG_ON(msg->channel >= omap_port->sst.channels); + queue = &omap_port->txqueue[msg->channel]; + } else { + BUG_ON(msg->channel >= omap_port->ssr.channels); + queue = &omap_port->rxqueue[msg->channel]; + } + msg->status = HSI_STATUS_QUEUED; + spin_lock_bh(&omap_port->lock); + list_add_tail(&msg->link, queue); + err = ssi_start_transfer(queue); + if (err < 0) { + list_del(&msg->link); + msg->status = HSI_STATUS_ERROR; + } + spin_unlock_bh(&omap_port->lock); + dev_dbg(&port->device, "msg status %d ttype %d ch %d\n", + msg->status, msg->ttype, msg->channel); + + return err; +} + +static u32 ssi_calculate_div(struct hsi_controller *ssi) +{ + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + u32 tx_fckrate = (u32) omap_ssi->fck_rate; + + /* / 2 : SSI TX clock is always half of the SSI functional clock */ + tx_fckrate >>= 1; + /* Round down when tx_fckrate % omap_ssi->max_speed == 0 */ + tx_fckrate--; + dev_dbg(&ssi->device, "TX div %d for fck_rate %lu Khz speed %d Kb/s\n", + tx_fckrate / omap_ssi->max_speed, omap_ssi->fck_rate, + omap_ssi->max_speed); + + return tx_fckrate / omap_ssi->max_speed; +} + +static void ssi_flush_queue(struct list_head *queue, struct hsi_client *cl) +{ + struct list_head *node, *tmp; + struct hsi_msg *msg; + + list_for_each_safe(node, tmp, queue) { + msg = list_entry(node, struct hsi_msg, link); + if ((cl) && (cl != msg->cl)) + continue; + list_del(node); + pr_debug("flush queue: ch %d, msg %p len %d type %d ctxt %p\n", + msg->channel, msg, msg->sgt.sgl->length, + msg->ttype, msg->context); + if (msg->destructor) + msg->destructor(msg); + else + hsi_free_msg(msg); + } +} + +static int ssi_setup(struct hsi_client *cl) +{ + struct hsi_port *port = to_hsi_port(cl->device.parent); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + void __iomem *sst = omap_port->sst_base; + void __iomem *ssr = omap_port->ssr_base; + u32 div; + u32 val; + int err = 0; + + pm_runtime_get_sync(omap_port->pdev); + spin_lock_bh(&omap_port->lock); + if (cl->tx_cfg.speed) + omap_ssi->max_speed = cl->tx_cfg.speed; + div = ssi_calculate_div(ssi); + if (div > SSI_MAX_DIVISOR) { + dev_err(&cl->device, "Invalid TX speed %d Mb/s (div %d)\n", + cl->tx_cfg.speed, div); + err = -EINVAL; + goto out; + } + /* Set TX/RX module to sleep to stop TX/RX during cfg update */ + writel_relaxed(SSI_MODE_SLEEP, sst + SSI_SST_MODE_REG); + writel_relaxed(SSI_MODE_SLEEP, ssr + SSI_SSR_MODE_REG); + /* Flush posted write */ + val = readl(ssr + SSI_SSR_MODE_REG); + /* TX */ + writel_relaxed(31, sst + SSI_SST_FRAMESIZE_REG); + writel_relaxed(div, sst + SSI_SST_DIVISOR_REG); + writel_relaxed(cl->tx_cfg.channels, sst + SSI_SST_CHANNELS_REG); + writel_relaxed(cl->tx_cfg.arb_mode, sst + SSI_SST_ARBMODE_REG); + writel_relaxed(cl->tx_cfg.mode, sst + SSI_SST_MODE_REG); + /* RX */ + writel_relaxed(31, ssr + SSI_SSR_FRAMESIZE_REG); + writel_relaxed(cl->rx_cfg.channels, ssr + SSI_SSR_CHANNELS_REG); + writel_relaxed(0, ssr + SSI_SSR_TIMEOUT_REG); + /* Cleanup the break queue if we leave FRAME mode */ + if ((omap_port->ssr.mode == SSI_MODE_FRAME) && + (cl->rx_cfg.mode != SSI_MODE_FRAME)) + ssi_flush_queue(&omap_port->brkqueue, cl); + writel_relaxed(cl->rx_cfg.mode, ssr + SSI_SSR_MODE_REG); + omap_port->channels = max(cl->rx_cfg.channels, cl->tx_cfg.channels); + /* Shadow registering for OFF mode */ + /* SST */ + omap_port->sst.divisor = div; + omap_port->sst.frame_size = 31; + omap_port->sst.channels = cl->tx_cfg.channels; + omap_port->sst.arb_mode = cl->tx_cfg.arb_mode; + omap_port->sst.mode = cl->tx_cfg.mode; + /* SSR */ + omap_port->ssr.frame_size = 31; + omap_port->ssr.timeout = 0; + omap_port->ssr.channels = cl->rx_cfg.channels; + omap_port->ssr.mode = cl->rx_cfg.mode; +out: + spin_unlock_bh(&omap_port->lock); + pm_runtime_put_sync(omap_port->pdev); + + return err; +} + +static int ssi_flush(struct hsi_client *cl) +{ + struct hsi_port *port = hsi_get_port(cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + struct hsi_msg *msg; + void __iomem *sst = omap_port->sst_base; + void __iomem *ssr = omap_port->ssr_base; + unsigned int i; + u32 err; + + pm_runtime_get_sync(omap_port->pdev); + spin_lock_bh(&omap_port->lock); + /* Stop all DMA transfers */ + for (i = 0; i < SSI_MAX_GDD_LCH; i++) { + msg = omap_ssi->gdd_trn[i].msg; + if (!msg || (port != hsi_get_port(msg->cl))) + continue; + writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i)); + if (msg->ttype == HSI_MSG_READ) + pm_runtime_put_sync(omap_port->pdev); + omap_ssi->gdd_trn[i].msg = NULL; + } + /* Flush all SST buffers */ + writel_relaxed(0, sst + SSI_SST_BUFSTATE_REG); + writel_relaxed(0, sst + SSI_SST_TXSTATE_REG); + /* Flush all SSR buffers */ + writel_relaxed(0, ssr + SSI_SSR_RXSTATE_REG); + writel_relaxed(0, ssr + SSI_SSR_BUFSTATE_REG); + /* Flush all errors */ + err = readl(ssr + SSI_SSR_ERROR_REG); + writel_relaxed(err, ssr + SSI_SSR_ERRORACK_REG); + /* Flush break */ + writel_relaxed(0, ssr + SSI_SSR_BREAK_REG); + /* Clear interrupts */ + writel_relaxed(0, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + writel_relaxed(0xffffff00, + omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0)); + writel_relaxed(0, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG); + writel(0xff, omap_ssi->sys + SSI_GDD_MPU_IRQ_STATUS_REG); + /* Dequeue all pending requests */ + for (i = 0; i < omap_port->channels; i++) { + /* Release write clocks */ + if (!list_empty(&omap_port->txqueue[i])) + pm_runtime_put_sync(omap_port->pdev); + ssi_flush_queue(&omap_port->txqueue[i], NULL); + ssi_flush_queue(&omap_port->rxqueue[i], NULL); + } + ssi_flush_queue(&omap_port->brkqueue, NULL); + spin_unlock_bh(&omap_port->lock); + pm_runtime_put_sync(omap_port->pdev); + + return 0; +} + +static int ssi_start_tx(struct hsi_client *cl) +{ + struct hsi_port *port = hsi_get_port(cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + dev_dbg(&port->device, "Wake out high %d\n", omap_port->wk_refcount); + + spin_lock_bh(&omap_port->wk_lock); + if (omap_port->wk_refcount++) { + spin_unlock_bh(&omap_port->wk_lock); + return 0; + } + pm_runtime_get_sync(omap_port->pdev); /* Grab clocks */ + writel(SSI_WAKE(0), omap_ssi->sys + SSI_SET_WAKE_REG(port->num)); + spin_unlock_bh(&omap_port->wk_lock); + + return 0; +} + +static int ssi_stop_tx(struct hsi_client *cl) +{ + struct hsi_port *port = hsi_get_port(cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + dev_dbg(&port->device, "Wake out low %d\n", omap_port->wk_refcount); + + spin_lock_bh(&omap_port->wk_lock); + BUG_ON(!omap_port->wk_refcount); + if (--omap_port->wk_refcount) { + spin_unlock_bh(&omap_port->wk_lock); + return 0; + } + writel(SSI_WAKE(0), + omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num)); + pm_runtime_put_sync(omap_port->pdev); /* Release clocks */ + spin_unlock_bh(&omap_port->wk_lock); + + return 0; +} + +static void ssi_transfer(struct omap_ssi_port *omap_port, + struct list_head *queue) +{ + struct hsi_msg *msg; + int err = -1; + + spin_lock_bh(&omap_port->lock); + while (err < 0) { + err = ssi_start_transfer(queue); + if (err < 0) { + msg = list_first_entry(queue, struct hsi_msg, link); + msg->status = HSI_STATUS_ERROR; + msg->actual_len = 0; + list_del(&msg->link); + spin_unlock_bh(&omap_port->lock); + msg->complete(msg); + spin_lock_bh(&omap_port->lock); + } + } + spin_unlock_bh(&omap_port->lock); +} + +static void ssi_cleanup_queues(struct hsi_client *cl) +{ + struct hsi_port *port = hsi_get_port(cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + struct hsi_msg *msg; + unsigned int i; + u32 rxbufstate = 0; + u32 txbufstate = 0; + u32 status = SSI_ERROROCCURED; + u32 tmp; + + ssi_flush_queue(&omap_port->brkqueue, cl); + if (list_empty(&omap_port->brkqueue)) + status |= SSI_BREAKDETECTED; + + for (i = 0; i < omap_port->channels; i++) { + if (list_empty(&omap_port->txqueue[i])) + continue; + msg = list_first_entry(&omap_port->txqueue[i], struct hsi_msg, + link); + if ((msg->cl == cl) && (msg->status == HSI_STATUS_PROCEEDING)) { + txbufstate |= (1 << i); + status |= SSI_DATAACCEPT(i); + /* Release the clocks writes, also GDD ones */ + pm_runtime_put_sync(omap_port->pdev); + } + ssi_flush_queue(&omap_port->txqueue[i], cl); + } + for (i = 0; i < omap_port->channels; i++) { + if (list_empty(&omap_port->rxqueue[i])) + continue; + msg = list_first_entry(&omap_port->rxqueue[i], struct hsi_msg, + link); + if ((msg->cl == cl) && (msg->status == HSI_STATUS_PROCEEDING)) { + rxbufstate |= (1 << i); + status |= SSI_DATAAVAILABLE(i); + } + ssi_flush_queue(&omap_port->rxqueue[i], cl); + /* Check if we keep the error detection interrupt armed */ + if (!list_empty(&omap_port->rxqueue[i])) + status &= ~SSI_ERROROCCURED; + } + /* Cleanup write buffers */ + tmp = readl(omap_port->sst_base + SSI_SST_BUFSTATE_REG); + tmp &= ~txbufstate; + writel_relaxed(tmp, omap_port->sst_base + SSI_SST_BUFSTATE_REG); + /* Cleanup read buffers */ + tmp = readl(omap_port->ssr_base + SSI_SSR_BUFSTATE_REG); + tmp &= ~rxbufstate; + writel_relaxed(tmp, omap_port->ssr_base + SSI_SSR_BUFSTATE_REG); + /* Disarm and ack pending interrupts */ + tmp = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + tmp &= ~status; + writel_relaxed(tmp, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + writel_relaxed(status, omap_ssi->sys + + SSI_MPU_STATUS_REG(port->num, 0)); +} + +static void ssi_cleanup_gdd(struct hsi_controller *ssi, struct hsi_client *cl) +{ + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + struct hsi_port *port = hsi_get_port(cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_msg *msg; + unsigned int i; + u32 val = 0; + u32 tmp; + + for (i = 0; i < SSI_MAX_GDD_LCH; i++) { + msg = omap_ssi->gdd_trn[i].msg; + if ((!msg) || (msg->cl != cl)) + continue; + writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i)); + val |= (1 << i); + /* + * Clock references for write will be handled in + * ssi_cleanup_queues + */ + if (msg->ttype == HSI_MSG_READ) + pm_runtime_put_sync(omap_port->pdev); + omap_ssi->gdd_trn[i].msg = NULL; + } + tmp = readl_relaxed(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG); + tmp &= ~val; + writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG); + writel(val, omap_ssi->sys + SSI_GDD_MPU_IRQ_STATUS_REG); +} + +static int ssi_set_port_mode(struct omap_ssi_port *omap_port, u32 mode) +{ + writel(mode, omap_port->sst_base + SSI_SST_MODE_REG); + writel(mode, omap_port->ssr_base + SSI_SSR_MODE_REG); + /* OCP barrier */ + mode = readl(omap_port->ssr_base + SSI_SSR_MODE_REG); + + return 0; +} + +static int ssi_release(struct hsi_client *cl) +{ + struct hsi_port *port = hsi_get_port(cl); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + + spin_lock_bh(&omap_port->lock); + pm_runtime_get_sync(omap_port->pdev); + /* Stop all the pending DMA requests for that client */ + ssi_cleanup_gdd(ssi, cl); + /* Now cleanup all the queues */ + ssi_cleanup_queues(cl); + pm_runtime_put_sync(omap_port->pdev); + /* If it is the last client of the port, do extra checks and cleanup */ + if (port->claimed <= 1) { + /* + * Drop the clock reference for the incoming wake line + * if it is still kept high by the other side. + */ + if (omap_port->wkin_cken) { + pm_runtime_put_sync(omap_port->pdev); + omap_port->wkin_cken = 0; + } + pm_runtime_get_sync(omap_port->pdev); + /* Stop any SSI TX/RX without a client */ + ssi_set_port_mode(omap_port, SSI_MODE_SLEEP); + omap_port->sst.mode = SSI_MODE_SLEEP; + omap_port->ssr.mode = SSI_MODE_SLEEP; + pm_runtime_put_sync(omap_port->pdev); + WARN_ON(omap_port->wk_refcount != 0); + } + spin_unlock_bh(&omap_port->lock); + + return 0; +} + + + +static void ssi_error(struct hsi_port *port) +{ + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + struct hsi_msg *msg; + unsigned int i; + u32 err; + u32 val; + u32 tmp; + + /* ACK error */ + err = readl(omap_port->ssr_base + SSI_SSR_ERROR_REG); + dev_err(&port->device, "SSI error: 0x%02x\n", err); + if (!err) { + dev_dbg(&port->device, "spurious SSI error ignored!\n"); + return; + } + spin_lock(&omap_ssi->lock); + /* Cancel all GDD read transfers */ + for (i = 0, val = 0; i < SSI_MAX_GDD_LCH; i++) { + msg = omap_ssi->gdd_trn[i].msg; + if ((msg) && (msg->ttype == HSI_MSG_READ)) { + writew_relaxed(0, omap_ssi->gdd + SSI_GDD_CCR_REG(i)); + val |= (1 << i); + omap_ssi->gdd_trn[i].msg = NULL; + } + } + tmp = readl(omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG); + tmp &= ~val; + writel_relaxed(tmp, omap_ssi->sys + SSI_GDD_MPU_IRQ_ENABLE_REG); + spin_unlock(&omap_ssi->lock); + /* Cancel all PIO read transfers */ + spin_lock(&omap_port->lock); + tmp = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + tmp &= 0xfeff00ff; /* Disable error & all dataavailable interrupts */ + writel_relaxed(tmp, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + /* ACK error */ + writel_relaxed(err, omap_port->ssr_base + SSI_SSR_ERRORACK_REG); + writel_relaxed(SSI_ERROROCCURED, + omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0)); + /* Signal the error all current pending read requests */ + for (i = 0; i < omap_port->channels; i++) { + if (list_empty(&omap_port->rxqueue[i])) + continue; + msg = list_first_entry(&omap_port->rxqueue[i], struct hsi_msg, + link); + list_del(&msg->link); + msg->status = HSI_STATUS_ERROR; + spin_unlock(&omap_port->lock); + msg->complete(msg); + /* Now restart queued reads if any */ + ssi_transfer(omap_port, &omap_port->rxqueue[i]); + spin_lock(&omap_port->lock); + } + spin_unlock(&omap_port->lock); +} + +static void ssi_break_complete(struct hsi_port *port) +{ + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + struct hsi_msg *msg; + struct hsi_msg *tmp; + u32 val; + + dev_dbg(&port->device, "HWBREAK received\n"); + + spin_lock(&omap_port->lock); + val = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + val &= ~SSI_BREAKDETECTED; + writel_relaxed(val, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + writel_relaxed(0, omap_port->ssr_base + SSI_SSR_BREAK_REG); + writel(SSI_BREAKDETECTED, + omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0)); + spin_unlock(&omap_port->lock); + + list_for_each_entry_safe(msg, tmp, &omap_port->brkqueue, link) { + msg->status = HSI_STATUS_COMPLETED; + spin_lock(&omap_port->lock); + list_del(&msg->link); + spin_unlock(&omap_port->lock); + msg->complete(msg); + } + +} + +static void ssi_pio_complete(struct hsi_port *port, struct list_head *queue) +{ + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_msg *msg; + u32 *buf; + u32 reg; + u32 val; + + spin_lock(&omap_port->lock); + msg = list_first_entry(queue, struct hsi_msg, link); + if ((!msg->sgt.nents) || (!msg->sgt.sgl->length)) { + msg->actual_len = 0; + msg->status = HSI_STATUS_PENDING; + } + if (msg->ttype == HSI_MSG_WRITE) + val = SSI_DATAACCEPT(msg->channel); + else + val = SSI_DATAAVAILABLE(msg->channel); + if (msg->status == HSI_STATUS_PROCEEDING) { + buf = sg_virt(msg->sgt.sgl) + msg->actual_len; + if (msg->ttype == HSI_MSG_WRITE) + writel(*buf, omap_port->sst_base + + SSI_SST_BUFFER_CH_REG(msg->channel)); + else + *buf = readl(omap_port->ssr_base + + SSI_SSR_BUFFER_CH_REG(msg->channel)); + dev_dbg(&port->device, "ch %d ttype %d 0x%08x\n", msg->channel, + msg->ttype, *buf); + msg->actual_len += sizeof(*buf); + if (msg->actual_len >= msg->sgt.sgl->length) + msg->status = HSI_STATUS_COMPLETED; + /* + * Wait for the last written frame to be really sent before + * we call the complete callback + */ + if ((msg->status == HSI_STATUS_PROCEEDING) || + ((msg->status == HSI_STATUS_COMPLETED) && + (msg->ttype == HSI_MSG_WRITE))) { + writel(val, omap_ssi->sys + + SSI_MPU_STATUS_REG(port->num, 0)); + spin_unlock(&omap_port->lock); + + return; + } + + } + /* Transfer completed at this point */ + reg = readl(omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + if (msg->ttype == HSI_MSG_WRITE) { + /* Release clocks for write transfer */ + pm_runtime_put_sync(omap_port->pdev); + } + reg &= ~val; + writel_relaxed(reg, omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + writel_relaxed(val, omap_ssi->sys + SSI_MPU_STATUS_REG(port->num, 0)); + list_del(&msg->link); + spin_unlock(&omap_port->lock); + msg->complete(msg); + ssi_transfer(omap_port, queue); +} + +static void ssi_pio_tasklet(unsigned long ssi_port) +{ + struct hsi_port *port = (struct hsi_port *)ssi_port; + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + void __iomem *sys = omap_ssi->sys; + unsigned int ch; + u32 status_reg; + + pm_runtime_get_sync(omap_port->pdev); + status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0)); + status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0)); + + for (ch = 0; ch < omap_port->channels; ch++) { + if (status_reg & SSI_DATAACCEPT(ch)) + ssi_pio_complete(port, &omap_port->txqueue[ch]); + if (status_reg & SSI_DATAAVAILABLE(ch)) + ssi_pio_complete(port, &omap_port->rxqueue[ch]); + } + if (status_reg & SSI_BREAKDETECTED) + ssi_break_complete(port); + if (status_reg & SSI_ERROROCCURED) + ssi_error(port); + + status_reg = readl(sys + SSI_MPU_STATUS_REG(port->num, 0)); + status_reg &= readl(sys + SSI_MPU_ENABLE_REG(port->num, 0)); + pm_runtime_put_sync(omap_port->pdev); + + if (status_reg) + tasklet_hi_schedule(&omap_port->pio_tasklet); + else + enable_irq(omap_port->irq); +} + +static irqreturn_t ssi_pio_isr(int irq, void *port) +{ + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + + tasklet_hi_schedule(&omap_port->pio_tasklet); + disable_irq_nosync(irq); + + return IRQ_HANDLED; +} + +static void ssi_wake_tasklet(unsigned long ssi_port) +{ + struct hsi_port *port = (struct hsi_port *)ssi_port; + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + if (ssi_wakein(port)) { + /** + * We can have a quick High-Low-High transition in the line. + * In such a case if we have long interrupt latencies, + * we can miss the low event or get twice a high event. + * This workaround will avoid breaking the clock reference + * count when such a situation ocurrs. + */ + spin_lock(&omap_port->lock); + if (!omap_port->wkin_cken) { + omap_port->wkin_cken = 1; + pm_runtime_get_sync(omap_port->pdev); + } + spin_unlock(&omap_port->lock); + dev_dbg(&ssi->device, "Wake in high\n"); + if (omap_port->wktest) { /* FIXME: HACK ! To be removed */ + writel(SSI_WAKE(0), + omap_ssi->sys + SSI_SET_WAKE_REG(port->num)); + } + hsi_event(port, HSI_EVENT_START_RX); + } else { + dev_dbg(&ssi->device, "Wake in low\n"); + if (omap_port->wktest) { /* FIXME: HACK ! To be removed */ + writel(SSI_WAKE(0), + omap_ssi->sys + SSI_CLEAR_WAKE_REG(port->num)); + } + hsi_event(port, HSI_EVENT_STOP_RX); + spin_lock(&omap_port->lock); + if (omap_port->wkin_cken) { + pm_runtime_put_sync(omap_port->pdev); + omap_port->wkin_cken = 0; + } + spin_unlock(&omap_port->lock); + } +} + +static irqreturn_t ssi_wake_isr(int irq __maybe_unused, void *ssi_port) +{ + struct omap_ssi_port *omap_port = hsi_port_drvdata(ssi_port); + + tasklet_hi_schedule(&omap_port->wake_tasklet); + + return IRQ_HANDLED; +} + +static int __init ssi_port_irq(struct hsi_port *port, + struct platform_device *pd) +{ + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct resource *irq; + int err; + + irq = platform_get_resource_byname(pd, IORESOURCE_IRQ, "mpu_irq0"); + if (!irq) { + dev_err(&port->device, "Port IRQ resource missing\n"); + return -ENXIO; + } + omap_port->irq = irq->start; + tasklet_init(&omap_port->pio_tasklet, ssi_pio_tasklet, + (unsigned long)port); + err = devm_request_irq(&port->device, omap_port->irq, ssi_pio_isr, + 0, irq->name, port); + if (err < 0) + dev_err(&port->device, "Request IRQ %d failed (%d)\n", + omap_port->irq, err); + return err; +} + +static int __init ssi_wake_irq(struct hsi_port *port, + struct platform_device *pd) +{ + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + int cawake_irq; + int err; + + if (omap_port->wake_gpio == -1) { + omap_port->wake_irq = -1; + return 0; + } + + cawake_irq = gpio_to_irq(omap_port->wake_gpio); + + omap_port->wake_irq = cawake_irq; + tasklet_init(&omap_port->wake_tasklet, ssi_wake_tasklet, + (unsigned long)port); + err = devm_request_irq(&port->device, cawake_irq, ssi_wake_isr, + IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, + "cawake", port); + if (err < 0) + dev_err(&port->device, "Request Wake in IRQ %d failed %d\n", + cawake_irq, err); + err = enable_irq_wake(cawake_irq); + if (err < 0) + dev_err(&port->device, "Enable wake on the wakeline in irq %d failed %d\n", + cawake_irq, err); + + return err; +} + +static void __init ssi_queues_init(struct omap_ssi_port *omap_port) +{ + unsigned int ch; + + for (ch = 0; ch < SSI_MAX_CHANNELS; ch++) { + INIT_LIST_HEAD(&omap_port->txqueue[ch]); + INIT_LIST_HEAD(&omap_port->rxqueue[ch]); + } + INIT_LIST_HEAD(&omap_port->brkqueue); +} + +static int __init ssi_port_get_iomem(struct platform_device *pd, + const char *name, void __iomem **pbase, dma_addr_t *phy) +{ + struct hsi_port *port = platform_get_drvdata(pd); + struct resource *mem; + struct resource *ioarea; + void __iomem *base; + + mem = platform_get_resource_byname(pd, IORESOURCE_MEM, name); + if (!mem) { + dev_err(&pd->dev, "IO memory region missing (%s)\n", name); + return -ENXIO; + } + ioarea = devm_request_mem_region(&port->device, mem->start, + resource_size(mem), dev_name(&pd->dev)); + if (!ioarea) { + dev_err(&pd->dev, "%s IO memory region request failed\n", + mem->name); + return -ENXIO; + } + base = devm_ioremap(&port->device, mem->start, resource_size(mem)); + if (!base) { + dev_err(&pd->dev, "%s IO remap failed\n", mem->name); + return -ENXIO; + } + *pbase = base; + + if (phy) + *phy = mem->start; + + return 0; +} + +static int __init ssi_port_probe(struct platform_device *pd) +{ + struct device_node *np = pd->dev.of_node; + struct hsi_port *port; + struct omap_ssi_port *omap_port; + struct hsi_controller *ssi = dev_get_drvdata(pd->dev.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + u32 cawake_gpio = 0; + u32 port_id; + int err; + + dev_dbg(&pd->dev, "init ssi port...\n"); + + err = ref_module(THIS_MODULE, ssi->owner); + if (err) { + dev_err(&pd->dev, "could not increment parent module refcount (err=%d)\n", + err); + return -ENODEV; + } + + if (!ssi->port || !omap_ssi->port) { + dev_err(&pd->dev, "ssi controller not initialized!\n"); + err = -ENODEV; + goto error; + } + + /* get id of first uninitialized port in controller */ + for (port_id = 0; port_id < ssi->num_ports && omap_ssi->port[port_id]; + port_id++) + ; + + if (port_id >= ssi->num_ports) { + dev_err(&pd->dev, "port id out of range!\n"); + err = -ENODEV; + goto error; + } + + port = ssi->port[port_id]; + + if (!np) { + dev_err(&pd->dev, "missing device tree data\n"); + err = -EINVAL; + goto error; + } + + cawake_gpio = of_get_named_gpio(np, "ti,ssi-cawake-gpio", 0); + if (cawake_gpio < 0) { + dev_err(&pd->dev, "DT data is missing cawake gpio (err=%d)\n", + cawake_gpio); + err = -ENODEV; + goto error; + } + + err = devm_gpio_request_one(&port->device, cawake_gpio, GPIOF_DIR_IN, + "cawake"); + if (err) { + dev_err(&pd->dev, "could not request cawake gpio (err=%d)!\n", + err); + err = -ENXIO; + goto error; + } + + omap_port = devm_kzalloc(&port->device, sizeof(*omap_port), GFP_KERNEL); + if (!omap_port) { + err = -ENOMEM; + goto error; + } + omap_port->wake_gpio = cawake_gpio; + omap_port->pdev = &pd->dev; + omap_port->port_id = port_id; + + /* initialize HSI port */ + port->async = ssi_async; + port->setup = ssi_setup; + port->flush = ssi_flush; + port->start_tx = ssi_start_tx; + port->stop_tx = ssi_stop_tx; + port->release = ssi_release; + hsi_port_set_drvdata(port, omap_port); + omap_ssi->port[port_id] = omap_port; + + platform_set_drvdata(pd, port); + + err = ssi_port_get_iomem(pd, "tx", &omap_port->sst_base, + &omap_port->sst_dma); + if (err < 0) + goto error; + err = ssi_port_get_iomem(pd, "rx", &omap_port->ssr_base, + &omap_port->ssr_dma); + if (err < 0) + goto error; + + err = ssi_port_irq(port, pd); + if (err < 0) + goto error; + err = ssi_wake_irq(port, pd); + if (err < 0) + goto error; + + ssi_queues_init(omap_port); + spin_lock_init(&omap_port->lock); + spin_lock_init(&omap_port->wk_lock); + omap_port->dev = &port->device; + + pm_runtime_irq_safe(omap_port->pdev); + pm_runtime_enable(omap_port->pdev); + +#ifdef CONFIG_DEBUG_FS + err = ssi_debug_add_port(omap_port, omap_ssi->dir); + if (err < 0) { + pm_runtime_disable(omap_port->pdev); + goto error; + } +#endif + + hsi_add_clients_from_dt(port, np); + + dev_info(&pd->dev, "ssi port %u successfully initialized (cawake=%d)\n", + port_id, cawake_gpio); + + return 0; + +error: + return err; +} + +static int __exit ssi_port_remove(struct platform_device *pd) +{ + struct hsi_port *port = platform_get_drvdata(pd); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + +#ifdef CONFIG_DEBUG_FS + ssi_debug_remove_port(port); +#endif + + hsi_port_unregister_clients(port); + + tasklet_kill(&omap_port->wake_tasklet); + tasklet_kill(&omap_port->pio_tasklet); + + port->async = hsi_dummy_msg; + port->setup = hsi_dummy_cl; + port->flush = hsi_dummy_cl; + port->start_tx = hsi_dummy_cl; + port->stop_tx = hsi_dummy_cl; + port->release = hsi_dummy_cl; + + omap_ssi->port[omap_port->port_id] = NULL; + platform_set_drvdata(pd, NULL); + pm_runtime_disable(&pd->dev); + + return 0; +} + +#ifdef CONFIG_PM_RUNTIME +static int ssi_save_port_ctx(struct omap_ssi_port *omap_port) +{ + struct hsi_port *port = to_hsi_port(omap_port->dev); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + omap_port->sys_mpu_enable = readl(omap_ssi->sys + + SSI_MPU_ENABLE_REG(port->num, 0)); + + return 0; +} + +static int ssi_restore_port_ctx(struct omap_ssi_port *omap_port) +{ + struct hsi_port *port = to_hsi_port(omap_port->dev); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + void __iomem *base; + + writel_relaxed(omap_port->sys_mpu_enable, + omap_ssi->sys + SSI_MPU_ENABLE_REG(port->num, 0)); + + /* SST context */ + base = omap_port->sst_base; + writel_relaxed(omap_port->sst.frame_size, base + SSI_SST_FRAMESIZE_REG); + writel_relaxed(omap_port->sst.channels, base + SSI_SST_CHANNELS_REG); + writel_relaxed(omap_port->sst.arb_mode, base + SSI_SST_ARBMODE_REG); + + /* SSR context */ + base = omap_port->ssr_base; + writel_relaxed(omap_port->ssr.frame_size, base + SSI_SSR_FRAMESIZE_REG); + writel_relaxed(omap_port->ssr.channels, base + SSI_SSR_CHANNELS_REG); + writel_relaxed(omap_port->ssr.timeout, base + SSI_SSR_TIMEOUT_REG); + + return 0; +} + +static int ssi_restore_port_mode(struct omap_ssi_port *omap_port) +{ + u32 mode; + + writel_relaxed(omap_port->sst.mode, + omap_port->sst_base + SSI_SST_MODE_REG); + writel_relaxed(omap_port->ssr.mode, + omap_port->ssr_base + SSI_SSR_MODE_REG); + /* OCP barrier */ + mode = readl(omap_port->ssr_base + SSI_SSR_MODE_REG); + + return 0; +} + +static int ssi_restore_divisor(struct omap_ssi_port *omap_port) +{ + writel_relaxed(omap_port->sst.divisor, + omap_port->sst_base + SSI_SST_DIVISOR_REG); + + return 0; +} + +static int omap_ssi_port_runtime_suspend(struct device *dev) +{ + struct hsi_port *port = dev_get_drvdata(dev); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + dev_dbg(dev, "port runtime suspend!\n"); + + ssi_set_port_mode(omap_port, SSI_MODE_SLEEP); + if (omap_ssi->get_loss) + omap_port->loss_count = + (*omap_ssi->get_loss)(ssi->device.parent); + ssi_save_port_ctx(omap_port); + + return 0; +} + +static int omap_ssi_port_runtime_resume(struct device *dev) +{ + struct hsi_port *port = dev_get_drvdata(dev); + struct omap_ssi_port *omap_port = hsi_port_drvdata(port); + struct hsi_controller *ssi = to_hsi_controller(port->device.parent); + struct omap_ssi_controller *omap_ssi = hsi_controller_drvdata(ssi); + + dev_dbg(dev, "port runtime resume!\n"); + + if ((omap_ssi->get_loss) && (omap_port->loss_count == + (*omap_ssi->get_loss)(ssi->device.parent))) + goto mode; /* We always need to restore the mode & TX divisor */ + + ssi_restore_port_ctx(omap_port); + +mode: + ssi_restore_divisor(omap_port); + ssi_restore_port_mode(omap_port); + + return 0; +} + +static const struct dev_pm_ops omap_ssi_port_pm_ops = { + SET_RUNTIME_PM_OPS(omap_ssi_port_runtime_suspend, + omap_ssi_port_runtime_resume, NULL) +}; + +#define DEV_PM_OPS (&omap_ssi_port_pm_ops) +#else +#define DEV_PM_OPS NULL +#endif + + +#ifdef CONFIG_OF +static const struct of_device_id omap_ssi_port_of_match[] = { + { .compatible = "ti,omap3-ssi-port", }, + {}, +}; +MODULE_DEVICE_TABLE(of, omap_ssi_port_of_match); +#else +#define omap_ssi_port_of_match NULL +#endif + +static struct platform_driver ssi_port_pdriver = { + .remove = __exit_p(ssi_port_remove), + .driver = { + .name = "omap_ssi_port", + .owner = THIS_MODULE, + .of_match_table = omap_ssi_port_of_match, + .pm = DEV_PM_OPS, + }, +}; + +module_platform_driver_probe(ssi_port_pdriver, ssi_port_probe); + +MODULE_ALIAS("platform:omap_ssi_port"); +MODULE_AUTHOR("Carlos Chinea <carlos.chinea@xxxxxxxxx>"); +MODULE_AUTHOR("Sebastian Reichel <sre@xxxxxxxxxx>"); +MODULE_DESCRIPTION("Synchronous Serial Interface Port Driver"); +MODULE_LICENSE("GPL v2"); diff --git a/drivers/hsi/controllers/omap_ssi_regs.h b/drivers/hsi/controllers/omap_ssi_regs.h new file mode 100644 index 0000000..08f98dd --- /dev/null +++ b/drivers/hsi/controllers/omap_ssi_regs.h @@ -0,0 +1,171 @@ +/* Hardware definitions for SSI. + * + * Copyright (C) 2010 Nokia Corporation. All rights reserved. + * + * Contact: Carlos Chinea <carlos.chinea@xxxxxxxxx> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#ifndef __OMAP_SSI_REGS_H__ +#define __OMAP_SSI_REGS_H__ + +/* + * SSI SYS registers + */ +#define SSI_REVISION_REG 0 +# define SSI_REV_MAJOR 0xf0 +# define SSI_REV_MINOR 0xf +#define SSI_SYSCONFIG_REG 0x10 +# define SSI_AUTOIDLE (1 << 0) +# define SSI_SOFTRESET (1 << 1) +# define SSI_SIDLEMODE_FORCE 0 +# define SSI_SIDLEMODE_NO (1 << 3) +# define SSI_SIDLEMODE_SMART (1 << 4) +# define SSI_SIDLEMODE_MASK 0x18 +# define SSI_MIDLEMODE_FORCE 0 +# define SSI_MIDLEMODE_NO (1 << 12) +# define SSI_MIDLEMODE_SMART (1 << 13) +# define SSI_MIDLEMODE_MASK 0x3000 +#define SSI_SYSSTATUS_REG 0x14 +# define SSI_RESETDONE 1 +#define SSI_MPU_STATUS_REG(port, irq) (0x808 + ((port) * 0x10) + ((irq) * 2)) +#define SSI_MPU_ENABLE_REG(port, irq) (0x80c + ((port) * 0x10) + ((irq) * 8)) +# define SSI_DATAACCEPT(channel) (1 << (channel)) +# define SSI_DATAAVAILABLE(channel) (1 << ((channel) + 8)) +# define SSI_DATAOVERRUN(channel) (1 << ((channel) + 16)) +# define SSI_ERROROCCURED (1 << 24) +# define SSI_BREAKDETECTED (1 << 25) +#define SSI_GDD_MPU_IRQ_STATUS_REG 0x0800 +#define SSI_GDD_MPU_IRQ_ENABLE_REG 0x0804 +# define SSI_GDD_LCH(channel) (1 << (channel)) +#define SSI_WAKE_REG(port) (0xc00 + ((port) * 0x10)) +#define SSI_CLEAR_WAKE_REG(port) (0xc04 + ((port) * 0x10)) +#define SSI_SET_WAKE_REG(port) (0xc08 + ((port) * 0x10)) +# define SSI_WAKE(channel) (1 << (channel)) +# define SSI_WAKE_MASK 0xff + +/* + * SSI SST registers + */ +#define SSI_SST_ID_REG 0 +#define SSI_SST_MODE_REG 4 +# define SSI_MODE_VAL_MASK 3 +# define SSI_MODE_SLEEP 0 +# define SSI_MODE_STREAM 1 +# define SSI_MODE_FRAME 2 +# define SSI_MODE_MULTIPOINTS 3 +#define SSI_SST_FRAMESIZE_REG 8 +# define SSI_FRAMESIZE_DEFAULT 31 +#define SSI_SST_TXSTATE_REG 0xc +# define SSI_TXSTATE_IDLE 0 +#define SSI_SST_BUFSTATE_REG 0x10 +# define SSI_FULL(channel) (1 << (channel)) +#define SSI_SST_DIVISOR_REG 0x18 +# define SSI_MAX_DIVISOR 127 +#define SSI_SST_BREAK_REG 0x20 +#define SSI_SST_CHANNELS_REG 0x24 +# define SSI_CHANNELS_DEFAULT 4 +#define SSI_SST_ARBMODE_REG 0x28 +# define SSI_ARBMODE_ROUNDROBIN 0 +# define SSI_ARBMODE_PRIORITY 1 +#define SSI_SST_BUFFER_CH_REG(channel) (0x80 + ((channel) * 4)) +#define SSI_SST_SWAPBUF_CH_REG(channel) (0xc0 + ((channel) * 4)) + +/* + * SSI SSR registers + */ +#define SSI_SSR_ID_REG 0 +#define SSI_SSR_MODE_REG 4 +#define SSI_SSR_FRAMESIZE_REG 8 +#define SSI_SSR_RXSTATE_REG 0xc +#define SSI_SSR_BUFSTATE_REG 0x10 +# define SSI_NOTEMPTY(channel) (1 << (channel)) +#define SSI_SSR_BREAK_REG 0x1c +#define SSI_SSR_ERROR_REG 0x20 +#define SSI_SSR_ERRORACK_REG 0x24 +#define SSI_SSR_OVERRUN_REG 0x2c +#define SSI_SSR_OVERRUNACK_REG 0x30 +#define SSI_SSR_TIMEOUT_REG 0x34 +# define SSI_TIMEOUT_DEFAULT 0 +#define SSI_SSR_CHANNELS_REG 0x28 +#define SSI_SSR_BUFFER_CH_REG(channel) (0x80 + ((channel) * 4)) +#define SSI_SSR_SWAPBUF_CH_REG(channel) (0xc0 + ((channel) * 4)) + +/* + * SSI GDD registers + */ +#define SSI_GDD_HW_ID_REG 0 +#define SSI_GDD_PPORT_ID_REG 0x10 +#define SSI_GDD_MPORT_ID_REG 0x14 +#define SSI_GDD_PPORT_SR_REG 0x20 +#define SSI_GDD_MPORT_SR_REG 0x24 +# define SSI_ACTIVE_LCH_NUM_MASK 0xff +#define SSI_GDD_TEST_REG 0x40 +# define SSI_TEST 1 +#define SSI_GDD_GCR_REG 0x100 +# define SSI_CLK_AUTOGATING_ON (1 << 3) +# define SSI_FREE (1 << 2) +# define SSI_SWITCH_OFF (1 << 0) +#define SSI_GDD_GRST_REG 0x200 +# define SSI_SWRESET 1 +#define SSI_GDD_CSDP_REG(channel) (0x800 + ((channel) * 0x40)) +# define SSI_DST_BURST_EN_MASK 0xc000 +# define SSI_DST_SINGLE_ACCESS0 0 +# define SSI_DST_SINGLE_ACCESS (1 << 14) +# define SSI_DST_BURST_4x32_BIT (2 << 14) +# define SSI_DST_BURST_8x32_BIT (3 << 14) +# define SSI_DST_MASK 0x1e00 +# define SSI_DST_MEMORY_PORT (8 << 9) +# define SSI_DST_PERIPHERAL_PORT (9 << 9) +# define SSI_SRC_BURST_EN_MASK 0x180 +# define SSI_SRC_SINGLE_ACCESS0 0 +# define SSI_SRC_SINGLE_ACCESS (1 << 7) +# define SSI_SRC_BURST_4x32_BIT (2 << 7) +# define SSI_SRC_BURST_8x32_BIT (3 << 7) +# define SSI_SRC_MASK 0x3c +# define SSI_SRC_MEMORY_PORT (8 << 2) +# define SSI_SRC_PERIPHERAL_PORT (9 << 2) +# define SSI_DATA_TYPE_MASK 3 +# define SSI_DATA_TYPE_S32 2 +#define SSI_GDD_CCR_REG(channel) (0x802 + ((channel) * 0x40)) +# define SSI_DST_AMODE_MASK (3 << 14) +# define SSI_DST_AMODE_CONST 0 +# define SSI_DST_AMODE_POSTINC (1 << 12) +# define SSI_SRC_AMODE_MASK (3 << 12) +# define SSI_SRC_AMODE_CONST 0 +# define SSI_SRC_AMODE_POSTINC (1 << 12) +# define SSI_CCR_ENABLE (1 << 7) +# define SSI_CCR_SYNC_MASK 0x1f +#define SSI_GDD_CICR_REG(channel) (0x804 + ((channel) * 0x40)) +# define SSI_BLOCK_IE (1 << 5) +# define SSI_HALF_IE (1 << 2) +# define SSI_TOUT_IE (1 << 0) +#define SSI_GDD_CSR_REG(channel) (0x806 + ((channel) * 0x40)) +# define SSI_CSR_SYNC (1 << 6) +# define SSI_CSR_BLOCK (1 << 5) +# define SSI_CSR_HALF (1 << 2) +# define SSI_CSR_TOUR (1 << 0) +#define SSI_GDD_CSSA_REG(channel) (0x808 + ((channel) * 0x40)) +#define SSI_GDD_CDSA_REG(channel) (0x80c + ((channel) * 0x40)) +#define SSI_GDD_CEN_REG(channel) (0x810 + ((channel) * 0x40)) +#define SSI_GDD_CSAC_REG(channel) (0x818 + ((channel) * 0x40)) +#define SSI_GDD_CDAC_REG(channel) (0x81a + ((channel) * 0x40)) +#define SSI_GDD_CLNK_CTRL_REG(channel) (0x828 + ((channel) * 0x40)) +# define SSI_ENABLE_LNK (1 << 15) +# define SSI_STOP_LNK (1 << 14) +# define SSI_NEXT_CH_ID_MASK 0xf + +#endif /* __OMAP_SSI_REGS_H__ */ -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html