From: Guenter Roeck <groeck@xxxxxxxxxxx> Introduce Juniper's PTX PMB CPLD I2C multiplexer driver. Signed-off-by: Debjit Ghosh <dghosh@xxxxxxxxxxx> Signed-off-by: Georgi Vlaev <gvlaev@xxxxxxxxxxx> Signed-off-by: Guenter Roeck <groeck@xxxxxxxxxxx> Signed-off-by: JawaharBalaji Thirumalaisamy <jawaharb@xxxxxxxxxxx> Signed-off-by: Rajat Jain <rajatjain@xxxxxxxxxxx> [Ported from Juniper kernel] Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx> --- drivers/i2c/muxes/Kconfig | 11 ++ drivers/i2c/muxes/Makefile | 1 + drivers/i2c/muxes/i2c-mux-ptxpmb.c | 299 +++++++++++++++++++++++++++++++++++++ 3 files changed, 311 insertions(+) create mode 100644 drivers/i2c/muxes/i2c-mux-ptxpmb.c diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig index e280c8e..f45a9cb 100644 --- a/drivers/i2c/muxes/Kconfig +++ b/drivers/i2c/muxes/Kconfig @@ -61,6 +61,17 @@ config I2C_MUX_PINCTRL This driver can also be built as a module. If so, the module will be called pinctrl-i2cmux. +config I2C_MUX_PTXPMB + tristate "Juniper PTX PMB CPLD I2C multiplexer" + depends on MFD_JUNIPER_CPLD + default y if MFD_JUNIPER_CPLD + help + Select this to enable the Juniper PTX PMB CPLD I2C multiplexer driver + on the relevant Juniper platforms. + + This driver can also be built as a module. If so, the module + will be called i2c-mux-ptxpmb-cpld. + config I2C_MUX_REG tristate "Register-based I2C multiplexer" help diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile index 7c267c2..78d8cba 100644 --- a/drivers/i2c/muxes/Makefile +++ b/drivers/i2c/muxes/Makefile @@ -9,6 +9,7 @@ obj-$(CONFIG_I2C_MUX_GPIO) += i2c-mux-gpio.o obj-$(CONFIG_I2C_MUX_PCA9541) += i2c-mux-pca9541.o obj-$(CONFIG_I2C_MUX_PCA954x) += i2c-mux-pca954x.o obj-$(CONFIG_I2C_MUX_PINCTRL) += i2c-mux-pinctrl.o +obj-$(CONFIG_I2C_MUX_PTXPMB) += i2c-mux-ptxpmb.o obj-$(CONFIG_I2C_MUX_REG) += i2c-mux-reg.o ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG diff --git a/drivers/i2c/muxes/i2c-mux-ptxpmb.c b/drivers/i2c/muxes/i2c-mux-ptxpmb.c new file mode 100644 index 0000000..e8c7aee --- /dev/null +++ b/drivers/i2c/muxes/i2c-mux-ptxpmb.c @@ -0,0 +1,299 @@ +/* + * PTX PMB CPLD I2C multiplexer + * + * Copyright (c) 2012, Juniper Networks. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/delay.h> +#include <linux/i2c.h> +#include <linux/i2c-mux.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/mfd/ptxpmb_cpld.h> +#include <linux/io.h> +#include <linux/of_device.h> + +struct i2c_mux_ptxpmb { + struct device *dev; + struct ptxpmb_mux_data *pdata; + struct pmb_boot_cpld __iomem *cpld; + struct i2c_adapter *parent; + int bus_count; + struct i2c_mux_core *muxc; +}; + +static const struct of_device_id i2c_mux_ptxpmb_of_match[] = { + { .compatible = "jnx,i2c-mux-ptxpmb-cpld", + .data = (void *)CPLD_TYPE_PTXPMB }, + { .compatible = "jnx,i2c-mux-ngpmb-bcpld", + .data = (void *)CPLD_TYPE_NGPMB }, + { }, +}; +MODULE_DEVICE_TABLE(of, i2c_mux_ptxpmb_of_match); + +#define I2C_GRP_FORCE_EN 0x80 + +static int i2c_mux_ptxpmb_select(struct i2c_mux_core *muxc, u32 chan) +{ + struct i2c_mux_ptxpmb *mux = i2c_mux_priv(muxc); + struct ptxpmb_mux_data *pdata = mux->pdata; + u8 group, enable, val; + + switch (pdata->cpld_type) { + case CPLD_TYPE_PTXPMB: + group = chan % pdata->num_channels; + enable = 1 << (chan / pdata->num_channels); + /* + * Writing into the enable register does not have an effect on + * FPC with P2020. It is necessary for FPC with P5020/P5040. + * The uKernel for SPMB uses undocumented CPLD registers to set + * group enable values (i2c_group_sel_force and + * i2c_group_en_force at offset 0x33 and 0x34). Bit 7 in + * i2c_group_sel_force must be set for this to work. + * i2c_group_en_force is active-low. This applies to SPMB with + * P2020; behavior with P5020/P5040 is unknown at this time. + */ + if (pdata->use_force) { + iowrite8(group | I2C_GRP_FORCE_EN, + &mux->cpld->i2c_group_sel_force); + iowrite8(~enable, &mux->cpld->i2c_group_en_force); + } else { + iowrite8(group, &mux->cpld->i2c_group_sel); + ioread8(&mux->cpld->i2c_group_sel); + iowrite8(enable, &mux->cpld->i2c_group_en); + ioread8(&mux->cpld->i2c_group_en); + } + break; + case CPLD_TYPE_NGPMB: + val = ioread8(&mux->cpld->gpio_2); + val &= ~NGPMB_I2C_GRP_SEL_MASK; + val |= (chan << NGPMB_I2C_GRP_SEL_LSB) & NGPMB_I2C_GRP_SEL_MASK; + iowrite8(val, &mux->cpld->gpio_2); + break; + } + udelay(50); + + return 0; +} + +static int i2c_mux_ptxpmb_deselect(struct i2c_mux_core *muxc, u32 chan) +{ + struct i2c_mux_ptxpmb *mux = i2c_mux_priv(muxc); + u8 val; + + switch (mux->pdata->cpld_type) { + case CPLD_TYPE_PTXPMB: + /* + * Restore defaults. Note that setting i2c_group_en does not + * have an effect on FPC with P2020, but is necessary for FPC + * with P5020/P5040. + */ + if (mux->pdata->use_force) { + iowrite8(0 | I2C_GRP_FORCE_EN, + &mux->cpld->i2c_group_sel_force); + iowrite8(0xff, &mux->cpld->i2c_group_en_force); + } else { + iowrite8(0, &mux->cpld->i2c_group_sel); + ioread8(&mux->cpld->i2c_group_sel); + iowrite8(0, &mux->cpld->i2c_group_en); + ioread8(&mux->cpld->i2c_group_en); + } + break; + case CPLD_TYPE_NGPMB: + /* Use the (unconnected) channel 3 to deselct */ + val = ioread8(&mux->cpld->gpio_2); + val &= ~NGPMB_I2C_GRP_SEL_MASK; + val |= (3 << NGPMB_I2C_GRP_SEL_LSB) & NGPMB_I2C_GRP_SEL_MASK; + iowrite8(val, &mux->cpld->gpio_2); + break; + } + return 0; +} + +#ifdef CONFIG_OF +static int i2c_mux_ptxpmb_parse_dt(struct i2c_mux_ptxpmb *mux, + struct device *dev) +{ + struct device_node *np = dev->of_node; + int ret; + struct device_node *adapter_np; + struct i2c_adapter *adapter; + const struct of_device_id *match; + + if (!np) + return 0; + + mux->pdata = devm_kzalloc(dev, sizeof(*mux->pdata), GFP_KERNEL); + if (!mux->pdata) + return -ENOMEM; + + match = of_match_device(i2c_mux_ptxpmb_of_match, dev); + if (match) + mux->pdata->cpld_type = (int)(unsigned long)match->data; + + ret = of_property_read_u32(np, "num-enable", &mux->pdata->num_enable); + if (ret) { + dev_err(dev, "num-enable missing\n"); + return -ENODEV; + } + + ret = of_property_read_u32(np, "num-channels", + &mux->pdata->num_channels); + if (ret) + mux->pdata->num_channels = 8; + + ret = of_property_read_u32(np, "base-bus-num", + &mux->pdata->base_bus_num); + if (ret) + mux->pdata->base_bus_num = 0; + + if (of_find_property(np, "use-force", NULL)) + mux->pdata->use_force = true; + + adapter_np = of_parse_phandle(np, "i2c-parent", 0); + if (!adapter_np) { + dev_err(dev, "Cannot parse i2c-parent\n"); + return -ENODEV; + } + adapter = of_find_i2c_adapter_by_node(adapter_np); + if (!adapter) { + dev_err(dev, "Cannot find parent bus\n"); + return -ENODEV; + } + mux->pdata->parent_bus_num = i2c_adapter_id(adapter); + put_device(&adapter->dev); + + return 0; +} +#else +static inline int i2c_mux_ptxpmb_parse_dt(struct i2c_mux_ptxpmb *mux, + struct device *dev) +{ + return 0; +} +#endif + +static int i2c_mux_ptxpmb_probe(struct platform_device *pdev) +{ + struct i2c_mux_ptxpmb *mux; + struct i2c_mux_core *muxc; + int i, ret; + struct resource *res; + struct device *dev = &pdev->dev; + + mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL); + if (!mux) + return -ENOMEM; + + platform_set_drvdata(pdev, mux); + + mux->dev = dev; + + mux->pdata = dev->platform_data; + if (!mux->pdata) { + ret = i2c_mux_ptxpmb_parse_dt(mux, dev); + if (ret < 0) + return ret; + } + if (!mux->pdata) { + dev_err(dev, "No platform / devicetree data\n"); + return -ENODEV; + } + + if (mux->pdata->num_enable <= 0 || mux->pdata->num_enable > 8 || + mux->pdata->num_channels <= 0 || mux->pdata->num_channels > 8) { + dev_err(dev, "Invalid platform data\n"); + return -EINVAL; + } + + mux->bus_count = mux->pdata->num_enable * mux->pdata->num_channels; + + mux->parent = i2c_get_adapter(mux->pdata->parent_bus_num); + if (!mux->parent) { + dev_err(dev, "Parent adapter (%d) not found\n", + mux->pdata->parent_bus_num); + return -ENODEV; + } + + muxc = i2c_mux_alloc(mux->parent, dev, mux->bus_count, 0, 0, + i2c_mux_ptxpmb_select, i2c_mux_ptxpmb_deselect); + if (!muxc) { + ret = -ENOMEM; + goto err; + } + muxc->priv = mux; + mux->muxc = muxc; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(dev, "No memory resource\n"); + ret = -ENODEV; + goto err; + } + + mux->cpld = devm_ioremap_nocache(dev, res->start, resource_size(res)); + if (!mux->cpld) { + ret = -ENOMEM; + goto err; + } + + for (i = 0; i < mux->bus_count; i++) { + u32 bus = mux->pdata->base_bus_num ? + mux->pdata->base_bus_num + i : 0; + + ret = i2c_mux_add_adapter(muxc, bus, i, 0); + if (ret) { + dev_err(dev, "Failed to add adapter %d\n", i); + goto err_del_adapter; + } + } + + return 0; + +err_del_adapter: + i2c_mux_del_adapters(mux->muxc); +err: + i2c_put_adapter(mux->parent); + return ret; +} + +static int i2c_mux_ptxpmb_remove(struct platform_device *pdev) +{ + struct i2c_mux_ptxpmb *mux = platform_get_drvdata(pdev); + + i2c_mux_del_adapters(mux->muxc); + i2c_put_adapter(mux->parent); + + return 0; +} + +static struct platform_driver i2c_mux_ptxpmb_driver = { + .driver = { + .name = "i2c-mux-ptxpmb-cpld", + .owner = THIS_MODULE, + .of_match_table = i2c_mux_ptxpmb_of_match, + }, + .probe = i2c_mux_ptxpmb_probe, + .remove = i2c_mux_ptxpmb_remove, +}; + +module_platform_driver(i2c_mux_ptxpmb_driver); + +MODULE_DESCRIPTION("ptxpmb CPLD I2C multiplexer driver"); +MODULE_AUTHOR("Guenter Roeck <groeck@xxxxxxxxxxx>"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:i2c-mux-ptxpmb-cpld"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
