The Pensando SoC controller is a SPI connected companion device that is present in all Pensando SoC board designs. The essential board management registers are accessed on chip select 0 with board mgmt IO support accessed using additional chip selects. Signed-off-by: Brad Larson <blarson@xxxxxxx> --- v14 changes: - Save 8 bytes of code size by swapping spi_device and reset_controller_dev in penctrl_device - Code simplification and clarity from review inputs - Set penctrl_spi_driver.driver.name to match compatible pensando-elba-ctrl - Remove unused include in amd-pensando-ctrl.h v13 changes: - Update include list in pensando-ctrl.c - Change variable spi_dev to spi throughout - Removed unneeded variable initialization, simplification of error checks, remove extra castings, and use dev_err_probe() - Sort the includes in amd-pensando-ctrl.h - Updates to cleanup if there is an error in penctrl_spi_probe() v12 changes: - Fix gcc-12.1.0 warning: Reported-by: kernel test robot <lkp@xxxxxxxxx> Link: https://lore.kernel.org/oe-kbuild-all/202303120925.SxLjwOd2-lkp@xxxxxxxxx/ v11 changes: - Fix the compatible to be specific 'amd,pensando-elba-ctrl' v10 changes: - Different driver implementation specific to this Pensando controller device. - Moved to soc/amd directory under new name based on guidance. This driver is of no use to any design other than all Pensando SoC based cards. - Removed use of builtin_driver, can be built as a module. v9 changes: - Previously patch 14/17 - After the change to the device tree node and squashing reset-cells into the parent simplified this to not use any MFD API and move it to drivers/spi/pensando-sr.c. - Change the naming to remove elba since this driver is common for all Pensando SoC designs . - Default yes SPI_PENSANDO_SR for ARCH_PENSANDO --- drivers/soc/Kconfig | 1 + drivers/soc/Makefile | 1 + drivers/soc/amd/Kconfig | 16 ++ drivers/soc/amd/Makefile | 2 + drivers/soc/amd/pensando-ctrl.c | 368 +++++++++++++++++++++++++ include/uapi/linux/amd-pensando-ctrl.h | 29 ++ 6 files changed, 417 insertions(+) create mode 100644 drivers/soc/amd/Kconfig create mode 100644 drivers/soc/amd/Makefile create mode 100644 drivers/soc/amd/pensando-ctrl.c create mode 100644 include/uapi/linux/amd-pensando-ctrl.h diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig index 4e176280113a..9e023f74e47c 100644 --- a/drivers/soc/Kconfig +++ b/drivers/soc/Kconfig @@ -2,6 +2,7 @@ menu "SOC (System On Chip) specific Drivers" source "drivers/soc/actions/Kconfig" +source "drivers/soc/amd/Kconfig" source "drivers/soc/amlogic/Kconfig" source "drivers/soc/apple/Kconfig" source "drivers/soc/aspeed/Kconfig" diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile index 3b0f9fb3b5c8..8914530f2721 100644 --- a/drivers/soc/Makefile +++ b/drivers/soc/Makefile @@ -4,6 +4,7 @@ # obj-$(CONFIG_ARCH_ACTIONS) += actions/ +obj-y += amd/ obj-y += apple/ obj-y += aspeed/ obj-$(CONFIG_ARCH_AT91) += atmel/ diff --git a/drivers/soc/amd/Kconfig b/drivers/soc/amd/Kconfig new file mode 100644 index 000000000000..011d5339d14e --- /dev/null +++ b/drivers/soc/amd/Kconfig @@ -0,0 +1,16 @@ +# SPDX-License-Identifier: GPL-2.0-only +menu "AMD Pensando SoC drivers" + +config AMD_PENSANDO_CTRL + tristate "AMD Pensando SoC Controller" + depends on SPI_MASTER=y + depends on (ARCH_PENSANDO && OF) || COMPILE_TEST + default ARCH_PENSANDO + select REGMAP_SPI + select MFD_SYSCON + help + Enables AMD Pensando SoC controller device support. This is a SPI + attached companion device in all Pensando SoC board designs which + provides essential board control/status registers and management IO + support. +endmenu diff --git a/drivers/soc/amd/Makefile b/drivers/soc/amd/Makefile new file mode 100644 index 000000000000..a2de0424f68d --- /dev/null +++ b/drivers/soc/amd/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +obj-$(CONFIG_AMD_PENSANDO_CTRL) += pensando-ctrl.o diff --git a/drivers/soc/amd/pensando-ctrl.c b/drivers/soc/amd/pensando-ctrl.c new file mode 100644 index 000000000000..ba37c8328853 --- /dev/null +++ b/drivers/soc/amd/pensando-ctrl.c @@ -0,0 +1,368 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * AMD Pensando SoC Controller + * + * Userspace interface and reset driver support for SPI connected Pensando SoC + * controller device. This device is present in all Pensando SoC designs and + * contains board control/status registers and management IO support. + * + * Copyright 2023 Advanced Micro Devices, Inc. + */ + +#include <linux/cdev.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/reset-controller.h> +#include <linux/spi/spi.h> + +#include <linux/amd-pensando-ctrl.h> + +struct penctrl_device { + struct reset_controller_dev rcdev; + struct spi_device *spi; +}; + +static DEFINE_MUTEX(spi_lock); +static dev_t penctrl_devt; +static struct penctrl_device *penctrl; +static struct class *penctrl_class; + +static long +penctrl_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + void __user *in_arg = (void __user *)arg; + struct penctrl_device *penctrl; + u8 tx_buf[PENCTRL_MAX_MSG_LEN]; + u8 rx_buf[PENCTRL_MAX_MSG_LEN]; + struct spi_transfer t[2] = {}; + struct penctrl_spi_xfer *msg; + struct spi_device *spi; + unsigned int num_msgs; + struct spi_message m; + u32 size; + int ret; + + /* Check for a valid command */ + if (_IOC_TYPE(cmd) != PENCTRL_IOC_MAGIC) + return -ENOTTY; + + if (_IOC_NR(cmd) > PENCTRL_IOC_MAXNR) + return -ENOTTY; + + if (((_IOC_DIR(cmd) & _IOC_READ)) && !access_ok(in_arg, _IOC_SIZE(cmd))) + return -EFAULT; + + if (((_IOC_DIR(cmd) & _IOC_WRITE)) && !access_ok(in_arg, _IOC_SIZE(cmd))) + return -EFAULT; + + /* Get a reference to the SPI device */ + penctrl = filp->private_data; + if (!penctrl) + return -ESHUTDOWN; + + spi = spi_dev_get(penctrl->spi); + if (!spi) + return -ESHUTDOWN; + + /* Verify and prepare SPI message */ + size = _IOC_SIZE(cmd); + num_msgs = size / sizeof(struct penctrl_spi_xfer); + if (num_msgs > 2 || size == 0 || size % sizeof(struct penctrl_spi_xfer)) { + ret = -EINVAL; + goto out_unlock; + } + msg = memdup_user((struct penctrl_spi_xfer *)arg, size); + if (IS_ERR(msg)) { + ret = PTR_ERR(msg); + goto out_unlock; + } + if (msg->len > PENCTRL_MAX_MSG_LEN) { + ret = -EINVAL; + goto out_unlock; + } + + t[0].tx_buf = tx_buf; + t[0].len = msg->len; + if (copy_from_user(tx_buf, (void __user *)msg->tx_buf, msg->len)) { + ret = -EFAULT; + goto out_unlock; + } + if (num_msgs > 1) { + msg++; + if (msg->len > PENCTRL_MAX_MSG_LEN) { + ret = -EINVAL; + goto out_unlock; + } + t[1].rx_buf = rx_buf; + t[1].len = msg->len; + } + spi_message_init_with_transfers(&m, t, num_msgs); + + /* Perform the transfer */ + mutex_lock(&spi_lock); + ret = spi_sync(spi, &m); + mutex_unlock(&spi_lock); + + if (ret || (num_msgs == 1)) + goto out_unlock; + + if (copy_to_user((void __user *)msg->rx_buf, rx_buf, msg->len)) + ret = -EFAULT; + +out_unlock: + spi_dev_put(spi); + return ret; +} + +static int penctrl_open(struct inode *inode, struct file *filp) +{ + struct spi_device *spi; + u8 current_cs; + + filp->private_data = penctrl; + current_cs = iminor(inode); + spi = penctrl->spi; + spi->chip_select = current_cs; + spi->cs_gpiod = spi->controller->cs_gpiods[current_cs]; + spi_setup(spi); + return stream_open(inode, filp); +} + +static int penctrl_release(struct inode *inode, struct file *filp) +{ + filp->private_data = NULL; + return 0; +} + +static const struct file_operations penctrl_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = penctrl_ioctl, + .open = penctrl_open, + .release = penctrl_release, + .llseek = no_llseek, +}; + +static int penctrl_regs_read(struct penctrl_device *penctrl, u32 reg, u32 *val) +{ + struct spi_device *spi = penctrl->spi; + struct spi_transfer t[2] = {}; + struct spi_message m; + u8 txbuf[3]; + u8 rxbuf[1]; + int ret; + + txbuf[0] = PENCTRL_SPI_CMD_REGRD; + txbuf[1] = reg; + txbuf[2] = 0; + t[0].tx_buf = txbuf; + t[0].len = sizeof(txbuf); + + rxbuf[0] = 0; + t[1].rx_buf = rxbuf; + t[1].len = sizeof(rxbuf); + + spi_message_init_with_transfers(&m, t, ARRAY_SIZE(t)); + ret = spi_sync(spi, &m); + if (ret == 0) + *val = rxbuf[0]; + + return ret; +} + +static int penctrl_regs_write(struct penctrl_device *penctrl, u32 reg, u32 val) +{ + struct spi_device *spi = penctrl->spi; + struct spi_transfer t; + struct spi_message m; + u8 txbuf[4]; + + txbuf[0] = PENCTRL_SPI_CMD_REGWR; + txbuf[1] = reg; + txbuf[2] = val; + txbuf[3] = 0; + + t.tx_buf = txbuf; + t.len = sizeof(txbuf); + spi_message_init_with_transfers(&m, &t, 1); + return spi_sync(spi, &m); +} + +static int penctrl_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct penctrl_device *penctrl = + container_of(rcdev, struct penctrl_device, rcdev); + struct spi_device *spi = penctrl->spi; + unsigned int val; + int ret; + + mutex_lock(&spi_lock); + spi->chip_select = 0; + spi->cs_gpiod = spi->controller->cs_gpiods[0]; + spi_setup(spi); + ret = penctrl_regs_read(penctrl, PENCTRL_REG_CTRL0, &val); + if (ret) { + dev_err(&spi->dev, "error reading ctrl0 reg\n"); + goto out_unlock; + } + + val |= BIT(6); + ret = penctrl_regs_write(penctrl, PENCTRL_REG_CTRL0, val); + if (ret) + dev_err(&spi->dev, "error writing ctrl0 reg\n"); + +out_unlock: + mutex_unlock(&spi_lock); + return ret; +} + +static int penctrl_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct penctrl_device *penctrl = + container_of(rcdev, struct penctrl_device, rcdev); + struct spi_device *spi = penctrl->spi; + unsigned int val; + int ret; + + mutex_lock(&spi_lock); + spi->chip_select = 0; + spi->cs_gpiod = spi->controller->cs_gpiods[0]; + spi_setup(spi); + ret = penctrl_regs_read(penctrl, PENCTRL_REG_CTRL0, &val); + if (ret) { + dev_err(&spi->dev, "error reading ctrl0 reg\n"); + goto out_unlock; + } + + val &= ~BIT(6); + ret = penctrl_regs_write(penctrl, PENCTRL_REG_CTRL0, val); + if (ret) + dev_err(&spi->dev, "error writing ctrl0 reg\n"); + +out_unlock: + mutex_unlock(&spi_lock); + return ret; +} + +static const struct reset_control_ops penctrl_reset_ops = { + .assert = penctrl_reset_assert, + .deassert = penctrl_reset_deassert, +}; + +static int penctrl_spi_probe(struct spi_device *spi) +{ + struct device *dev; + struct cdev *cdev; + u32 num_cs; + int ret; + u32 cs; + + ret = device_property_read_u32(spi->dev.parent, "num-cs", &num_cs); + if (ret) + return dev_err_probe(&spi->dev, ret, + "number of chip-selects not defined\n"); + + ret = alloc_chrdev_region(&penctrl_devt, 0, num_cs, "penctrl"); + if (ret) + return dev_err_probe(&spi->dev, ret, + "failed to alloc chrdev region\n"); + + penctrl_class = class_create(THIS_MODULE, "penctrl"); + if (IS_ERR(penctrl_class)) { + ret = dev_err_probe(&spi->dev, PTR_ERR(penctrl_class), + "failed to create class\n"); + goto unregister_chrdev; + } + + cdev = cdev_alloc(); + if (!cdev) { + ret = dev_err_probe(&spi->dev, -ENOMEM, + "allocation of cdev failed\n"); + goto destroy_class; + } + cdev->owner = THIS_MODULE; + cdev_init(cdev, &penctrl_fops); + + ret = cdev_add(cdev, penctrl_devt, num_cs); + if (ret) { + ret = dev_err_probe(&spi->dev, ret, + "register of cdev failed\n"); + goto free_cdev; + } + + /* Allocate driver data */ + penctrl = kzalloc(sizeof(*penctrl), GFP_KERNEL); + if (!penctrl) { + ret = -ENOMEM; + goto free_cdev; + } + penctrl->spi = spi; + mutex_init(&spi_lock); + + /* Create a device for each chip select */ + for (cs = 0; cs < num_cs; cs++) { + dev = device_create(penctrl_class, + &spi->dev, + MKDEV(MAJOR(penctrl_devt), cs), + penctrl, + "penctrl0.%d", + cs); + if (IS_ERR(dev)) { + ret = dev_err_probe(&spi->dev, PTR_ERR(dev), + "error creating device\n"); + goto destroy_device; + } + dev_dbg(&spi->dev, "created device major %u, minor %d\n", + MAJOR(penctrl_devt), cs); + } + + /* Register reset controller */ + penctrl->rcdev.dev = &spi->dev; + penctrl->rcdev.ops = &penctrl_reset_ops; + penctrl->rcdev.owner = THIS_MODULE; + penctrl->rcdev.of_node = spi->dev.of_node; + penctrl->rcdev.nr_resets = 1; + + ret = reset_controller_register(&penctrl->rcdev); + if (ret) + return dev_err_probe(&spi->dev, ret, + "failed to register reset controller\n"); + return 0; + +destroy_device: + for (cs = 0; cs < num_cs; cs++) + device_destroy(penctrl_class, MKDEV(MAJOR(penctrl_devt), cs)); + kfree(penctrl); +free_cdev: + cdev_del(cdev); +destroy_class: + class_destroy(penctrl_class); +unregister_chrdev: + unregister_chrdev(MAJOR(penctrl_devt), "penctrl"); + + return ret; +} + +static const struct of_device_id penctrl_dt_match[] = { + { .compatible = "amd,pensando-elba-ctrl" }, + { /* sentinel */ } +}; + +static struct spi_driver penctrl_spi_driver = { + .probe = penctrl_spi_probe, + .driver = { + .name = "pensando-elba-ctrl", + .of_match_table = penctrl_dt_match, + }, +}; +module_spi_driver(penctrl_spi_driver); + +MODULE_AUTHOR("Brad Larson <blarson@xxxxxxx>"); +MODULE_DESCRIPTION("AMD Pensando SoC Controller via SPI"); +MODULE_LICENSE("GPL"); diff --git a/include/uapi/linux/amd-pensando-ctrl.h b/include/uapi/linux/amd-pensando-ctrl.h new file mode 100644 index 000000000000..e5f9f0dfe146 --- /dev/null +++ b/include/uapi/linux/amd-pensando-ctrl.h @@ -0,0 +1,29 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +/* + * Userspace interface for /dev/penctrl + * + * This file can be used by applications that need to communicate + * with the AMD Pensando SoC controller device via the ioctl interface. + */ +#ifndef _UAPI_LINUX_AMD_PENSANDO_CTRL_H +#define _UAPI_LINUX_AMD_PENSANDO_CTRL_H + +#include <linux/types.h> + +#define PENCTRL_SPI_CMD_REGRD 0x0b +#define PENCTRL_SPI_CMD_REGWR 0x02 +#define PENCTRL_IOC_MAGIC 'k' +#define PENCTRL_IOC_MAXNR 0 +#define PENCTRL_MAX_MSG_LEN 16 +#define PENCTRL_MAX_REG 0xff +#define PENCTRL_REG_CTRL0 0x10 + +struct penctrl_spi_xfer { + __u64 tx_buf; + __u64 rx_buf; + __u32 len; + __u32 speed_hz; + __u64 compat; +}; + +#endif /* _UAPI_LINUX_AMD_PENSANDO_CTRL_H */ base-commit: fe15c26ee26efa11741a7b632e9f23b01aca4cc6 -- 2.17.1
