From: Oleksandr Suvorov oleksandr.suvorov@toradex.com
Initial support for Fairchild's 8 bit I2C gpio expander FXL6408. The CONFIG_FXL6408_GPIO define enables support for such devices.
Based on: https://patchwork.kernel.org/patch/9148419/
Signed-off-by: Oleksandr Suvorov oleksandr.suvorov@toradex.com Reviewed-by: Simon Glass sjg@chromium.org Tested-by: Marcel Ziswiler marcel.ziswiler@toradex.com Signed-off-by: Oleksandr Suvorov cryosay@gmail.com Signed-off-by: Oleksandr Suvorov oleksandr.suvorov@foundries.io ---
Changes in v3: - fix a warning: ...drivers/gpio/gpio-fxl6408.c:348:15: warning: format ‘%ld’ expects argument of type ‘long int’, but argument 3 has type ‘int’ [-Wformat=]... - add Tested-by record.
drivers/gpio/Kconfig | 7 + drivers/gpio/Makefile | 1 + drivers/gpio/gpio-fxl6408.c | 366 ++++++++++++++++++++++++++++++++++++ 3 files changed, 374 insertions(+) create mode 100644 drivers/gpio/gpio-fxl6408.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 4a89c1a62b..f56e4cc261 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -123,6 +123,13 @@ config DA8XX_GPIO help This driver supports the DA8xx GPIO controller
+config FXL6408_GPIO + bool "FXL6408 I2C GPIO expander driver" + depends on DM_GPIO && DM_I2C + help + This driver supports the Fairchild FXL6408 device. FXL6408 is a + fully configurable 8-bit I2C-controlled GPIO expander. + config INTEL_BROADWELL_GPIO bool "Intel Broadwell GPIO driver" depends on DM diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 58f4704f6b..83d8b5c9d8 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_AT91_GPIO) += at91_gpio.o obj-$(CONFIG_ATMEL_PIO4) += atmel_pio4.o obj-$(CONFIG_BCM6345_GPIO) += bcm6345_gpio.o obj-$(CONFIG_CORTINA_GPIO) += cortina_gpio.o +obj-$(CONFIG_FXL6408_GPIO) += gpio-fxl6408.o obj-$(CONFIG_INTEL_GPIO) += intel_gpio.o obj-$(CONFIG_INTEL_ICH6_GPIO) += intel_ich6_gpio.o obj-$(CONFIG_INTEL_BROADWELL_GPIO) += intel_broadwell_gpio.o diff --git a/drivers/gpio/gpio-fxl6408.c b/drivers/gpio/gpio-fxl6408.c new file mode 100644 index 0000000000..dbc68618f9 --- /dev/null +++ b/drivers/gpio/gpio-fxl6408.c @@ -0,0 +1,366 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2021 Toradex + * Copyright (C) 2016 Broadcom + */ + +/** + * DOC: FXL6408 I2C to GPIO expander. + * + * This chip has 8 GPIO lines out of it, and is controlled by an I2C + * bus (a pair of lines), providing 4x expansion of GPIO lines. It + * also provides an interrupt line out for notifying of state changes. + * + * Any preconfigured state will be left in place until the GPIO lines + * get activated. At power on, everything is treated as an input, + * default input is HIGH and pulled-up, all interrupts are masked. + * + * Documentation can be found at: + * https://www.fairchildsemi.com/datasheets/FX/FXL6408.pdf + * + * This driver bases on: + * - the original driver by Eric Anholt eric@anholt.net: + * https://patchwork.kernel.org/patch/9148419/ + * - the Toradex version by Max Krummenacher max.krummenacher@toradex.com: + * http://git.toradex.com/cgit/linux-toradex.git/tree/drivers/gpio/gpio-fxl6408... + * - the U-boot PCA953x driver by Peng Fan van.freenix@gmail.com: + * drivers/gpio/pca953x_gpio.c + * + * TODO: + * - Add interrupts support + * - Replace deprecated callbacks direction_input/output() with set_flags() + */ + +#include <common.h> +#include <dm.h> +#include <dm/device_compat.h> +#include <i2c.h> +#include <log.h> +#include <asm-generic/gpio.h> +#include <asm/global_data.h> +#include <linux/bitops.h> +#include <dt-bindings/gpio/gpio.h> + +#define REG_DEVID_CTRL 0x01 +# define SW_RST BIT(0) +# define RST_INT BIT(1) +/* 0b101 is the Manufacturer's ID assigned to Fairchild by Nokia */ +# define MF_ID_FAIRCHILD 5 + +/* Bits set here indicate that the GPIO is an output */ +#define REG_IO_DIR 0x03 + +/* + * Bits set here, when the corresponding bit of REG_IO_DIR is set, drive + * the output high instead of low. + */ +#define REG_OUT_STATE 0x05 + +/* Bits here make the output High-Z, instead of the OUTPUT value */ +#define REG_OUT_HIGH_Z 0x07 + +/* + * Bits here define the expected input state of the GPIO. + * INTERRUPT_STATUS bits will be set when the INPUT transitions away + * from this value. + */ +#define REG_IN_DEFAULT_STATE 0x09 + +/* + * Bits here enable either pull up or pull down according to + * REG_PULL_MODE. + */ +#define REG_PULL_ENABLE 0x0b + +/* + * Bits set here selects a pull-up/pull-down state of pin, which + * is configured as Input and the corresponding REG_PULL_ENABLE bit is + * set. + */ +#define REG_PULL_MODE 0x0d + +/* Returns the current status (1 = HIGH) of the input pins */ +#define REG_IN_STATUS 0x0f + +/* Mask of pins which can generate interrupts */ +#define REG_INT_MASK 0x11 + +/* Mask of pins which have generated an interrupt. Cleared on read */ +#define REG_INT_STATUS 0x13 + +/* Manufacturer's ID getting from Device ID & Ctrl register */ +enum { + MF_ID_MASK = GENMASK(7, 5), + MF_ID_SHIFT = 5, +}; + +/* Firmware revision getting from Device ID & Ctrl register */ +enum { + FW_REV_MASK = GENMASK(4, 2), + FW_REV_SHIFT = 2, +}; + +enum io_direction { + DIR_IN, + DIR_OUT, +}; + +/* + * struct fxl6408_info - Data for fxl6408 + * + * @dev: udevice structure for the device + * @addr: i2c slave address + * @reg_io_dir: hold the value of direction register + * @reg_output: hold the value of output register + */ +struct fxl6408_info { + struct udevice *dev; + int addr; + u8 device_id; + u8 reg_io_dir; + u8 reg_output; +}; + +static inline int fxl6408_write(struct udevice *dev, int reg, u8 val) +{ + return dm_i2c_write(dev, reg, &val, 1); +} + +static int fxl6408_read(struct udevice *dev, int reg) +{ + int ret; + u8 tmp; + + ret = dm_i2c_read(dev, reg, &tmp, 1); + if (!ret) + ret = tmp; + + return ret; +} + +/* + * fxl6408_is_output() - check whether the gpio configures as either + * output or input. + * Return: false - input, true - output. + */ +static bool fxl6408_is_output(struct udevice *dev, int offset) +{ + struct fxl6408_info *info = dev_get_plat(dev); + + return info->reg_io_dir & BIT(offset); +} + +static int fxl6408_get_value(struct udevice *dev, uint offset) +{ + int ret, reg = fxl6408_is_output(dev, offset) ? REG_OUT_STATE : REG_IN_STATUS; + + ret = fxl6408_read(dev, reg); + if (ret < 0) + return ret; + + return !!(ret & BIT(offset)); +} + +static int fxl6408_set_value(struct udevice *dev, uint offset, int value) +{ + struct fxl6408_info *info = dev_get_plat(dev); + u8 val; + int ret; + + if (value) + val = info->reg_output | BIT(offset); + else + val = info->reg_output & ~BIT(offset); + + ret = fxl6408_write(dev, REG_OUT_STATE, val); + if (ret < 0) + return ret; + + info->reg_output = val; + + return 0; +} + +static int fxl6408_set_direction(struct udevice *dev, uint offset, + enum io_direction dir) +{ + struct fxl6408_info *info = dev_get_plat(dev); + u8 val; + int ret; + + if (dir == DIR_IN) + val = info->reg_io_dir & ~BIT(offset); + else + val = info->reg_io_dir | BIT(offset); + + ret = fxl6408_write(dev, REG_IO_DIR, val); + if (ret < 0) + return ret; + + info->reg_io_dir = val; + + return 0; +} + +static int fxl6408_direction_input(struct udevice *dev, uint offset) +{ + return fxl6408_set_direction(dev, offset, DIR_IN); +} + +static int fxl6408_direction_output(struct udevice *dev, uint offset, int value) +{ + int ret; + + /* Configure output value */ + ret = fxl6408_set_value(dev, offset, value); + if (ret < 0) + return ret; + /* Configure direction as output */ + fxl6408_set_direction(dev, offset, DIR_OUT); + + return 0; +} + +static int fxl6408_get_function(struct udevice *dev, uint offset) +{ + if (fxl6408_is_output(dev, offset)) + return GPIOF_OUTPUT; + else + return GPIOF_INPUT; +} + +static int fxl6408_xlate(struct udevice *dev, struct gpio_desc *desc, + struct ofnode_phandle_args *args) +{ + desc->offset = args->args[0]; + desc->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW : 0; + + return 0; +} + +static const struct dm_gpio_ops fxl6408_ops = { + .direction_input = fxl6408_direction_input, + .direction_output = fxl6408_direction_output, + .get_value = fxl6408_get_value, + .set_value = fxl6408_set_value, + .get_function = fxl6408_get_function, + .xlate = fxl6408_xlate, +}; + +static int fxl6408_probe(struct udevice *dev) +{ + struct fxl6408_info *info = dev_get_plat(dev); + struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev); + char name[32], label[32], *str; + int addr; + int ret; + int size; + const u8 *tmp; + u32 val32; + + addr = dev_read_addr(dev); + if (addr == 0) + return -EINVAL; + info->addr = addr; + + /* + * Check the device ID register to see if it's responding. + * This also clears RST_INT as a side effect, so we won't get + * the "we've been power cycled" interrupt once interrupts + * being enabled. + */ + ret = fxl6408_read(dev, REG_DEVID_CTRL); + if (ret < 0) { + dev_err(dev, "FXL6408 probe returned %d\n", ret); + return ret; + } + + if ((ret & MF_ID_MASK) >> MF_ID_SHIFT != MF_ID_FAIRCHILD) { + dev_err(dev, "FXL6408 probe: wrong Manufacturer's ID: 0x%02x\n", ret); + return -ENXIO; + } + info->device_id = ret; + + /* + * Disable High-Z of outputs, so that the OUTPUT updates + * actually take effect. + */ + ret = fxl6408_write(dev, REG_OUT_HIGH_Z, (u8)0); + if (ret < 0) { + dev_err(dev, "Error writing High-Z register\n"); + return ret; + } + + /* + * If configured, set initial output state and direction, + * otherwise read them from the chip. + */ + if (dev_read_u32(dev, "initial_io_dir", &val32)) { + ret = fxl6408_read(dev, REG_IO_DIR); + if (ret < 0) { + dev_err(dev, "Error reading direction register\n"); + return ret; + } + info->reg_io_dir = ret; + } else { + info->reg_io_dir = val32 & 0xFF; + ret = fxl6408_write(dev, REG_IO_DIR, info->reg_io_dir); + if (ret < 0) { + dev_err(dev, "Error setting direction register\n"); + return ret; + } + } + + if (dev_read_u32(dev, "initial_output", &val32)) { + ret = fxl6408_read(dev, REG_OUT_STATE); + if (ret < 0) { + dev_err(dev, "Error reading output register\n"); + return ret; + } + info->reg_output = ret; + } else { + info->reg_output = val32 & 0xFF; + ret = fxl6408_write(dev, REG_OUT_STATE, info->reg_output); + if (ret < 0) { + dev_err(dev, "Error setting output register\n"); + return ret; + } + } + + tmp = dev_read_prop(dev, "label", &size); + if (tmp) { + size = min(size, (int)sizeof(label) - 1); + memcpy(label, tmp, size); + label[size] = '\0'; + snprintf(name, sizeof(name), "%s@%x_", label, info->addr); + } else { + snprintf(name, sizeof(name), "gpio@%x_", info->addr); + } + + str = strdup(name); + if (!str) + return -ENOMEM; + + uc_priv->bank_name = str; + uc_priv->gpio_count = dev_get_driver_data(dev); + uc_priv->gpio_base = -1; + + dev_dbg(dev, "%s (FW rev. %d) is ready\n", str, + (info->device_id & MF_ID_MASK) >> MF_ID_SHIFT); + + return 0; +} + +static const struct udevice_id fxl6408_ids[] = { + { .compatible = "fcs,fxl6408", .data = 8 }, + { } +}; + +U_BOOT_DRIVER(fxl6408_gpio) = { + .name = "fxl6408_gpio", + .id = UCLASS_GPIO, + .ops = &fxl6408_ops, + .probe = fxl6408_probe, + .of_match = fxl6408_ids, + .plat_auto = sizeof(struct fxl6408_info), +};