diff options
Diffstat (limited to 'drivers/pinctrl/pinctrl-aw9523.c')
| -rw-r--r-- | drivers/pinctrl/pinctrl-aw9523.c | 1119 |
1 files changed, 1119 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinctrl-aw9523.c b/drivers/pinctrl/pinctrl-aw9523.c new file mode 100644 index 0000000000..4edd371c46 --- /dev/null +++ b/drivers/pinctrl/pinctrl-aw9523.c @@ -0,0 +1,1119 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Awinic AW9523B i2c pin controller driver + * Copyright (c) 2020, AngeloGioacchino Del Regno + * <angelogioacchino.delregno@somainline.org> + */ + +#include <linux/bitfield.h> +#include <linux/gpio/consumer.h> +#include <linux/gpio/driver.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/mutex.h> +#include <linux/module.h> +#include <linux/pinctrl/pinconf.h> +#include <linux/pinctrl/pinctrl.h> +#include <linux/pinctrl/pinmux.h> +#include <linux/pinctrl/pinconf-generic.h> +#include <linux/property.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> +#include <linux/slab.h> + +#define AW9523_MAX_FUNCS 2 +#define AW9523_NUM_PORTS 2 +#define AW9523_PINS_PER_PORT 8 + +/* + * HW needs at least 20uS for reset and at least 1-2uS to recover from + * reset, but we have to account for eventual board quirks, if any: + * for this reason, keep reset asserted for 50uS and wait for 20uS + * to recover from the reset. + */ +#define AW9523_HW_RESET_US 50 +#define AW9523_HW_RESET_RECOVERY_US 20 + +/* Port 0: P0_0...P0_7 - Port 1: P1_0...P1_7 */ +#define AW9523_PIN_TO_PORT(pin) (pin >> 3) +#define AW9523_REG_IN_STATE(pin) (0x00 + AW9523_PIN_TO_PORT(pin)) +#define AW9523_REG_OUT_STATE(pin) (0x02 + AW9523_PIN_TO_PORT(pin)) +#define AW9523_REG_CONF_STATE(pin) (0x04 + AW9523_PIN_TO_PORT(pin)) +#define AW9523_REG_INTR_DIS(pin) (0x06 + AW9523_PIN_TO_PORT(pin)) +#define AW9523_REG_CHIPID 0x10 +#define AW9523_VAL_EXPECTED_CHIPID 0x23 + +#define AW9523_REG_GCR 0x11 +#define AW9523_GCR_ISEL_MASK GENMASK(0, 1) +#define AW9523_GCR_GPOMD_MASK BIT(4) + +#define AW9523_REG_PORT_MODE(pin) (0x12 + AW9523_PIN_TO_PORT(pin)) +#define AW9523_REG_SOFT_RESET 0x7f +#define AW9523_VAL_RESET 0x00 + +/* + * struct aw9523_irq - Interrupt controller structure + * @lock: mutex locking for the irq bus + * @irqchip: structure holding irqchip params + * @cached_gpio: stores the previous gpio status for bit comparison + */ +struct aw9523_irq { + struct mutex lock; + struct irq_chip *irqchip; + u16 cached_gpio; +}; + +/* + * struct aw9523_pinmux - Pin mux params + * @name: Name of the mux + * @grps: Groups of the mux + * @num_grps: Number of groups (sizeof array grps) + */ +struct aw9523_pinmux { + const char *name; + const char * const *grps; + const u8 num_grps; +}; + +/* + * struct aw9523 - Main driver structure + * @dev: device handle + * @regmap: regmap handle for current device + * @i2c_lock: Mutex lock for i2c operations + * @reset_gpio: Hardware reset (RSTN) signal GPIO + * @vio_vreg: VCC regulator (Optional) + * @pctl: pinctrl handle for current device + * @gpio: structure holding gpiochip params + * @irq: Interrupt controller structure + */ +struct aw9523 { + struct device *dev; + struct regmap *regmap; + struct mutex i2c_lock; + struct gpio_desc *reset_gpio; + struct regulator *vio_vreg; + struct pinctrl_dev *pctl; + struct gpio_chip gpio; + struct aw9523_irq *irq; +}; + +static const struct pinctrl_pin_desc aw9523_pins[] = { + /* Port 0 */ + PINCTRL_PIN(0, "gpio0"), + PINCTRL_PIN(1, "gpio1"), + PINCTRL_PIN(2, "gpio2"), + PINCTRL_PIN(3, "gpio3"), + PINCTRL_PIN(4, "gpio4"), + PINCTRL_PIN(5, "gpio5"), + PINCTRL_PIN(6, "gpio6"), + PINCTRL_PIN(7, "gpio7"), + + /* Port 1 */ + PINCTRL_PIN(8, "gpio8"), + PINCTRL_PIN(9, "gpio9"), + PINCTRL_PIN(10, "gpio10"), + PINCTRL_PIN(11, "gpio11"), + PINCTRL_PIN(12, "gpio12"), + PINCTRL_PIN(13, "gpio13"), + PINCTRL_PIN(14, "gpio14"), + PINCTRL_PIN(15, "gpio15"), +}; + +static int aw9523_pinctrl_get_groups_count(struct pinctrl_dev *pctldev) +{ + return ARRAY_SIZE(aw9523_pins); +} + +static const char *aw9523_pinctrl_get_group_name(struct pinctrl_dev *pctldev, + unsigned int selector) +{ + return aw9523_pins[selector].name; +} + +static int aw9523_pinctrl_get_group_pins(struct pinctrl_dev *pctldev, + unsigned int selector, + const unsigned int **pins, + unsigned int *num_pins) +{ + *pins = &aw9523_pins[selector].number; + *num_pins = 1; + return 0; +} + +static const struct pinctrl_ops aw9523_pinctrl_ops = { + .get_groups_count = aw9523_pinctrl_get_groups_count, + .get_group_pins = aw9523_pinctrl_get_group_pins, + .get_group_name = aw9523_pinctrl_get_group_name, + .dt_node_to_map = pinconf_generic_dt_node_to_map_pin, + .dt_free_map = pinconf_generic_dt_free_map, +}; + +static const char * const gpio_pwm_groups[] = { + "gpio0", "gpio1", "gpio2", "gpio3", "gpio4", "gpio5", + "gpio6", "gpio7", "gpio8", "gpio9", "gpio10", "gpio11", + "gpio12", "gpio13", "gpio14", "gpio15" +}; + +/* Warning: Do NOT reorder this array */ +static const struct aw9523_pinmux aw9523_pmx[] = { + { + .name = "pwm", + .grps = gpio_pwm_groups, + .num_grps = ARRAY_SIZE(gpio_pwm_groups), + }, + { + .name = "gpio", + .grps = gpio_pwm_groups, + .num_grps = ARRAY_SIZE(gpio_pwm_groups), + }, +}; + +static int aw9523_pmx_get_funcs_count(struct pinctrl_dev *pctl) +{ + return ARRAY_SIZE(aw9523_pmx); +} + +static const char *aw9523_pmx_get_fname(struct pinctrl_dev *pctl, + unsigned int sel) +{ + return aw9523_pmx[sel].name; +} + +static int aw9523_pmx_get_groups(struct pinctrl_dev *pctl, unsigned int sel, + const char * const **groups, + unsigned int * const num_groups) +{ + *groups = aw9523_pmx[sel].grps; + *num_groups = aw9523_pmx[sel].num_grps; + return 0; +} + +static int aw9523_pmx_set_mux(struct pinctrl_dev *pctl, unsigned int fsel, + unsigned int grp) +{ + struct aw9523 *awi = pinctrl_dev_get_drvdata(pctl); + int ret, pin = aw9523_pins[grp].number % AW9523_PINS_PER_PORT; + + if (fsel >= ARRAY_SIZE(aw9523_pmx)) + return -EINVAL; + + /* + * This maps directly to the aw9523_pmx array: programming a + * high bit means "gpio" and a low bit means "pwm". + */ + mutex_lock(&awi->i2c_lock); + ret = regmap_update_bits(awi->regmap, AW9523_REG_PORT_MODE(pin), + BIT(pin), (fsel ? BIT(pin) : 0)); + mutex_unlock(&awi->i2c_lock); + return ret; +} + +static const struct pinmux_ops aw9523_pinmux_ops = { + .get_functions_count = aw9523_pmx_get_funcs_count, + .get_function_name = aw9523_pmx_get_fname, + .get_function_groups = aw9523_pmx_get_groups, + .set_mux = aw9523_pmx_set_mux, +}; + +static int aw9523_pcfg_param_to_reg(enum pin_config_param pcp, int pin, u8 *r) +{ + u8 reg; + + switch (pcp) { + case PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: + case PIN_CONFIG_BIAS_PULL_DOWN: + case PIN_CONFIG_BIAS_PULL_UP: + reg = AW9523_REG_IN_STATE(pin); + break; + case PIN_CONFIG_DRIVE_OPEN_DRAIN: + case PIN_CONFIG_DRIVE_PUSH_PULL: + reg = AW9523_REG_GCR; + break; + case PIN_CONFIG_INPUT_ENABLE: + case PIN_CONFIG_OUTPUT_ENABLE: + reg = AW9523_REG_CONF_STATE(pin); + break; + case PIN_CONFIG_OUTPUT: + reg = AW9523_REG_OUT_STATE(pin); + break; + default: + return -EOPNOTSUPP; + } + *r = reg; + + return 0; +} + +static int aw9523_pconf_get(struct pinctrl_dev *pctldev, unsigned int pin, + unsigned long *config) +{ + struct aw9523 *awi = pinctrl_dev_get_drvdata(pctldev); + enum pin_config_param param = pinconf_to_config_param(*config); + int regbit = pin % AW9523_PINS_PER_PORT; + unsigned int val; + u8 reg; + int rc; + + rc = aw9523_pcfg_param_to_reg(param, pin, ®); + if (rc) + return rc; + + mutex_lock(&awi->i2c_lock); + rc = regmap_read(awi->regmap, reg, &val); + mutex_unlock(&awi->i2c_lock); + if (rc) + return rc; + + switch (param) { + case PIN_CONFIG_BIAS_PULL_UP: + case PIN_CONFIG_INPUT_ENABLE: + case PIN_CONFIG_OUTPUT: + val &= BIT(regbit); + break; + case PIN_CONFIG_BIAS_PULL_DOWN: + case PIN_CONFIG_OUTPUT_ENABLE: + val &= BIT(regbit); + val = !val; + break; + case PIN_CONFIG_DRIVE_OPEN_DRAIN: + if (pin >= AW9523_PINS_PER_PORT) + val = 0; + else + val = !FIELD_GET(AW9523_GCR_GPOMD_MASK, val); + break; + case PIN_CONFIG_DRIVE_PUSH_PULL: + if (pin >= AW9523_PINS_PER_PORT) + val = 1; + else + val = FIELD_GET(AW9523_GCR_GPOMD_MASK, val); + break; + default: + return -EOPNOTSUPP; + } + if (val < 1) + return -EINVAL; + + *config = pinconf_to_config_packed(param, !!val); + + return rc; +} + +static int aw9523_pconf_set(struct pinctrl_dev *pctldev, unsigned int pin, + unsigned long *configs, unsigned int num_configs) +{ + struct aw9523 *awi = pinctrl_dev_get_drvdata(pctldev); + enum pin_config_param param; + int regbit = pin % AW9523_PINS_PER_PORT; + u32 arg; + u8 reg; + unsigned int mask, val; + int i, rc; + + mutex_lock(&awi->i2c_lock); + for (i = 0; i < num_configs; i++) { + param = pinconf_to_config_param(configs[i]); + arg = pinconf_to_config_argument(configs[i]); + + rc = aw9523_pcfg_param_to_reg(param, pin, ®); + if (rc) + goto end; + + switch (param) { + case PIN_CONFIG_OUTPUT: + /* First, enable pin output */ + rc = regmap_update_bits(awi->regmap, + AW9523_REG_CONF_STATE(pin), + BIT(regbit), 0); + if (rc) + goto end; + + /* Then, fall through to config output level */ + fallthrough; + case PIN_CONFIG_OUTPUT_ENABLE: + arg = !arg; + fallthrough; + case PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: + case PIN_CONFIG_BIAS_PULL_DOWN: + case PIN_CONFIG_BIAS_PULL_UP: + case PIN_CONFIG_INPUT_ENABLE: + mask = BIT(regbit); + val = arg ? BIT(regbit) : 0; + break; + case PIN_CONFIG_DRIVE_OPEN_DRAIN: + /* Open-Drain is supported only on port 0 */ + if (pin >= AW9523_PINS_PER_PORT) { + rc = -EOPNOTSUPP; + goto end; + } + mask = AW9523_GCR_GPOMD_MASK; + val = 0; + break; + case PIN_CONFIG_DRIVE_PUSH_PULL: + /* Port 1 is always Push-Pull */ + if (pin >= AW9523_PINS_PER_PORT) { + mask = 0; + val = 0; + continue; + } + mask = AW9523_GCR_GPOMD_MASK; + val = AW9523_GCR_GPOMD_MASK; + break; + default: + rc = -EOPNOTSUPP; + goto end; + } + + rc = regmap_update_bits(awi->regmap, reg, mask, val); + if (rc) + goto end; + } +end: + mutex_unlock(&awi->i2c_lock); + return rc; +} + +static const struct pinconf_ops aw9523_pinconf_ops = { + .pin_config_get = aw9523_pconf_get, + .pin_config_set = aw9523_pconf_set, + .is_generic = true, +}; + +/* + * aw9523_get_pin_direction - Get pin direction + * @regmap: Regmap structure + * @pin: gpiolib pin number + * @n: pin index in port register + * + * Return: Pin direction for success or negative number for error + */ +static int aw9523_get_pin_direction(struct regmap *regmap, u8 pin, u8 n) +{ + int ret; + + ret = regmap_test_bits(regmap, AW9523_REG_CONF_STATE(pin), BIT(n)); + if (ret < 0) + return ret; + + return ret ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT; +} + +/* + * aw9523_get_port_state - Get input or output state for entire port + * @regmap: Regmap structure + * @pin: gpiolib pin number + * @regbit: hw pin index, used to retrieve port number + * @state: returned port state + * + * Return: Zero for success or negative number for error + */ +static int aw9523_get_port_state(struct regmap *regmap, u8 pin, + u8 regbit, unsigned int *state) +{ + u8 reg; + int dir; + + dir = aw9523_get_pin_direction(regmap, pin, regbit); + if (dir < 0) + return dir; + + if (dir == GPIO_LINE_DIRECTION_IN) + reg = AW9523_REG_IN_STATE(pin); + else + reg = AW9523_REG_OUT_STATE(pin); + + return regmap_read(regmap, reg, state); +} + +static int aw9523_gpio_irq_type(struct irq_data *d, unsigned int type) +{ + switch (type) { + case IRQ_TYPE_NONE: + case IRQ_TYPE_EDGE_BOTH: + return 0; + default: + return -EINVAL; + }; +} + +/* + * aw9523_irq_mask - Mask interrupt + * @d: irq data + * + * Sets which interrupt to mask in the bitmap; + * The interrupt will be masked when unlocking the irq bus. + */ +static void aw9523_irq_mask(struct irq_data *d) +{ + struct aw9523 *awi = gpiochip_get_data(irq_data_get_irq_chip_data(d)); + unsigned int n = d->hwirq % AW9523_PINS_PER_PORT; + + regmap_update_bits(awi->regmap, + AW9523_REG_INTR_DIS(d->hwirq), + BIT(n), BIT(n)); + gpiochip_disable_irq(&awi->gpio, irqd_to_hwirq(d)); +} + +/* + * aw9523_irq_unmask - Unmask interrupt + * @d: irq data + * + * Sets which interrupt to unmask in the bitmap; + * The interrupt will be masked when unlocking the irq bus. + */ +static void aw9523_irq_unmask(struct irq_data *d) +{ + struct aw9523 *awi = gpiochip_get_data(irq_data_get_irq_chip_data(d)); + unsigned int n = d->hwirq % AW9523_PINS_PER_PORT; + + gpiochip_enable_irq(&awi->gpio, irqd_to_hwirq(d)); + regmap_update_bits(awi->regmap, + AW9523_REG_INTR_DIS(d->hwirq), + BIT(n), 0); +} + +static irqreturn_t aw9523_irq_thread_func(int irq, void *dev_id) +{ + struct aw9523 *awi = (struct aw9523 *)dev_id; + unsigned long n, val = 0; + unsigned long changed_gpio; + unsigned int tmp, port_pin, i, ret; + + for (i = 0; i < AW9523_NUM_PORTS; i++) { + port_pin = i * AW9523_PINS_PER_PORT; + ret = regmap_read(awi->regmap, + AW9523_REG_IN_STATE(port_pin), + &tmp); + if (ret) + return ret; + val |= (u8)tmp << (i * 8); + } + + /* Handle GPIO input release interrupt as well */ + changed_gpio = awi->irq->cached_gpio ^ val; + awi->irq->cached_gpio = val; + + /* + * To avoid up to four *slow* i2c reads from any driver hooked + * up to our interrupts, just check for the irq_find_mapping + * result: if the interrupt is not mapped, then we don't want + * to care about it. + */ + for_each_set_bit(n, &changed_gpio, awi->gpio.ngpio) { + tmp = irq_find_mapping(awi->gpio.irq.domain, n); + if (tmp <= 0) + continue; + handle_nested_irq(tmp); + } + + return IRQ_HANDLED; +} + +/* + * aw9523_irq_bus_lock - Grab lock for interrupt operation + * @d: irq data + */ +static void aw9523_irq_bus_lock(struct irq_data *d) +{ + struct aw9523 *awi = gpiochip_get_data(irq_data_get_irq_chip_data(d)); + + mutex_lock(&awi->irq->lock); + regcache_cache_only(awi->regmap, true); +} + +/* + * aw9523_irq_bus_sync_unlock - Synchronize state and unlock + * @d: irq data + * + * Writes the interrupt mask bits (found in the bit map) to the + * hardware, then unlocks the bus. + */ +static void aw9523_irq_bus_sync_unlock(struct irq_data *d) +{ + struct aw9523 *awi = gpiochip_get_data(irq_data_get_irq_chip_data(d)); + + regcache_cache_only(awi->regmap, false); + regcache_sync(awi->regmap); + mutex_unlock(&awi->irq->lock); +} + +static int aw9523_gpio_get_direction(struct gpio_chip *chip, + unsigned int offset) +{ + struct aw9523 *awi = gpiochip_get_data(chip); + u8 regbit = offset % AW9523_PINS_PER_PORT; + int ret; + + mutex_lock(&awi->i2c_lock); + ret = aw9523_get_pin_direction(awi->regmap, offset, regbit); + mutex_unlock(&awi->i2c_lock); + + return ret; +} + +static int aw9523_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + struct aw9523 *awi = gpiochip_get_data(chip); + u8 regbit = offset % AW9523_PINS_PER_PORT; + unsigned int val; + int ret; + + mutex_lock(&awi->i2c_lock); + ret = aw9523_get_port_state(awi->regmap, offset, regbit, &val); + mutex_unlock(&awi->i2c_lock); + if (ret) + return ret; + + return !!(val & BIT(regbit)); +} + +/** + * _aw9523_gpio_get_multiple - Get I/O state for an entire port + * @regmap: Regmap structure + * @pin: gpiolib pin number + * @regbit: hw pin index, used to retrieve port number + * @state: returned port I/O state + * + * Return: Zero for success or negative number for error + */ +static int _aw9523_gpio_get_multiple(struct aw9523 *awi, u8 regbit, + u8 *state, u8 mask) +{ + u32 dir_in, val; + u8 m; + int ret; + + /* Registers are 8-bits wide */ + ret = regmap_read(awi->regmap, AW9523_REG_CONF_STATE(regbit), &dir_in); + if (ret) + return ret; + *state = 0; + + m = mask & dir_in; + if (m) { + ret = regmap_read(awi->regmap, AW9523_REG_IN_STATE(regbit), + &val); + if (ret) + return ret; + *state |= (u8)val & m; + } + + m = mask & ~dir_in; + if (m) { + ret = regmap_read(awi->regmap, AW9523_REG_OUT_STATE(regbit), + &val); + if (ret) + return ret; + *state |= (u8)val & m; + } + + return 0; +} + +static int aw9523_gpio_get_multiple(struct gpio_chip *chip, + unsigned long *mask, + unsigned long *bits) +{ + struct aw9523 *awi = gpiochip_get_data(chip); + u8 m, state = 0; + int ret; + + mutex_lock(&awi->i2c_lock); + + /* Port 0 (gpio 0-7) */ + m = *mask & U8_MAX; + if (m) { + ret = _aw9523_gpio_get_multiple(awi, 0, &state, m); + if (ret) + goto out; + } + *bits = state; + + /* Port 1 (gpio 8-15) */ + m = (*mask >> 8) & U8_MAX; + if (m) { + ret = _aw9523_gpio_get_multiple(awi, AW9523_PINS_PER_PORT, + &state, m); + if (ret) + goto out; + + *bits |= (state << 8); + } +out: + mutex_unlock(&awi->i2c_lock); + return ret; +} + +static void aw9523_gpio_set_multiple(struct gpio_chip *chip, + unsigned long *mask, + unsigned long *bits) +{ + struct aw9523 *awi = gpiochip_get_data(chip); + u8 mask_lo, mask_hi, bits_lo, bits_hi; + unsigned int reg; + int ret = 0; + + mask_lo = *mask & U8_MAX; + mask_hi = (*mask >> 8) & U8_MAX; + mutex_lock(&awi->i2c_lock); + if (mask_hi) { + reg = AW9523_REG_OUT_STATE(AW9523_PINS_PER_PORT); + bits_hi = (*bits >> 8) & U8_MAX; + + ret = regmap_write_bits(awi->regmap, reg, mask_hi, bits_hi); + if (ret) { + dev_warn(awi->dev, "Cannot write port1 out level\n"); + goto out; + } + } + if (mask_lo) { + reg = AW9523_REG_OUT_STATE(0); + bits_lo = *bits & U8_MAX; + ret = regmap_write_bits(awi->regmap, reg, mask_lo, bits_lo); + if (ret) + dev_warn(awi->dev, "Cannot write port0 out level\n"); + } +out: + mutex_unlock(&awi->i2c_lock); +} + +static void aw9523_gpio_set(struct gpio_chip *chip, + unsigned int offset, int value) +{ + struct aw9523 *awi = gpiochip_get_data(chip); + u8 regbit = offset % AW9523_PINS_PER_PORT; + + mutex_lock(&awi->i2c_lock); + regmap_update_bits(awi->regmap, AW9523_REG_OUT_STATE(offset), + BIT(regbit), value ? BIT(regbit) : 0); + mutex_unlock(&awi->i2c_lock); +} + + +static int aw9523_direction_input(struct gpio_chip *chip, unsigned int offset) +{ + struct aw9523 *awi = gpiochip_get_data(chip); + u8 regbit = offset % AW9523_PINS_PER_PORT; + int ret; + + mutex_lock(&awi->i2c_lock); + ret = regmap_update_bits(awi->regmap, AW9523_REG_CONF_STATE(offset), + BIT(regbit), BIT(regbit)); + mutex_unlock(&awi->i2c_lock); + + return ret; +} + +static int aw9523_direction_output(struct gpio_chip *chip, + unsigned int offset, int value) +{ + struct aw9523 *awi = gpiochip_get_data(chip); + u8 regbit = offset % AW9523_PINS_PER_PORT; + int ret; + + mutex_lock(&awi->i2c_lock); + ret = regmap_update_bits(awi->regmap, AW9523_REG_OUT_STATE(offset), + BIT(regbit), value ? BIT(regbit) : 0); + if (ret) + goto end; + + ret = regmap_update_bits(awi->regmap, AW9523_REG_CONF_STATE(offset), + BIT(regbit), 0); +end: + mutex_unlock(&awi->i2c_lock); + return ret; +} + +static int aw9523_drive_reset_gpio(struct aw9523 *awi) +{ + unsigned int chip_id; + int ret; + + /* + * If the chip is already configured for any reason, then we + * will probably succeed in sending the soft reset signal to + * the hardware through I2C: this operation takes less time + * compared to a full HW reset and it gives the same results. + */ + ret = regmap_write(awi->regmap, AW9523_REG_SOFT_RESET, 0); + if (ret == 0) + goto done; + + dev_dbg(awi->dev, "Cannot execute soft reset: trying hard reset\n"); + ret = gpiod_direction_output(awi->reset_gpio, 0); + if (ret) + return ret; + + /* The reset pulse has to be longer than 20uS due to deglitch */ + usleep_range(AW9523_HW_RESET_US, AW9523_HW_RESET_US + 1); + + ret = gpiod_direction_output(awi->reset_gpio, 1); + if (ret) + return ret; +done: + /* The HW needs at least 1uS to reliably recover after reset */ + usleep_range(AW9523_HW_RESET_RECOVERY_US, + AW9523_HW_RESET_RECOVERY_US + 1); + + /* Check the ChipID */ + ret = regmap_read(awi->regmap, AW9523_REG_CHIPID, &chip_id); + if (ret) { + dev_err(awi->dev, "Cannot read Chip ID: %d\n", ret); + return ret; + } + if (chip_id != AW9523_VAL_EXPECTED_CHIPID) { + dev_err(awi->dev, "Bad ChipID; read 0x%x, expected 0x%x\n", + chip_id, AW9523_VAL_EXPECTED_CHIPID); + return -EINVAL; + } + + return 0; +} + +static int aw9523_hw_reset(struct aw9523 *awi) +{ + int ret, max_retries = 2; + + /* Sometimes the chip needs more than one reset cycle */ + do { + ret = aw9523_drive_reset_gpio(awi); + if (ret == 0) + break; + max_retries--; + } while (max_retries); + + return ret; +} + +static int aw9523_init_gpiochip(struct aw9523 *awi, unsigned int npins) +{ + struct device *dev = awi->dev; + struct gpio_chip *gc = &awi->gpio; + + gc->label = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL); + if (!gc->label) + return -ENOMEM; + + gc->base = -1; + gc->ngpio = npins; + gc->get_direction = aw9523_gpio_get_direction; + gc->direction_input = aw9523_direction_input; + gc->direction_output = aw9523_direction_output; + gc->get = aw9523_gpio_get; + gc->get_multiple = aw9523_gpio_get_multiple; + gc->set = aw9523_gpio_set; + gc->set_multiple = aw9523_gpio_set_multiple; + gc->set_config = gpiochip_generic_config; + gc->parent = dev; + gc->owner = THIS_MODULE; + gc->can_sleep = false; + + return 0; +} + +static const struct irq_chip aw9523_irq_chip = { + .name = "aw9523", + .irq_mask = aw9523_irq_mask, + .irq_unmask = aw9523_irq_unmask, + .irq_bus_lock = aw9523_irq_bus_lock, + .irq_bus_sync_unlock = aw9523_irq_bus_sync_unlock, + .irq_set_type = aw9523_gpio_irq_type, + .flags = IRQCHIP_IMMUTABLE, + GPIOCHIP_IRQ_RESOURCE_HELPERS, +}; + +static int aw9523_init_irq(struct aw9523 *awi, int irq) +{ + struct device *dev = awi->dev; + struct gpio_irq_chip *girq; + struct irq_chip *irqchip; + int ret; + + if (!device_property_read_bool(dev, "interrupt-controller")) + return 0; + + irqchip = devm_kzalloc(dev, sizeof(*irqchip), GFP_KERNEL); + if (!irqchip) + return -ENOMEM; + + awi->irq = devm_kzalloc(dev, sizeof(*awi->irq), GFP_KERNEL); + if (!awi->irq) + return -ENOMEM; + + awi->irq->irqchip = irqchip; + mutex_init(&awi->irq->lock); + + ret = devm_request_threaded_irq(dev, irq, NULL, aw9523_irq_thread_func, + IRQF_ONESHOT, dev_name(dev), awi); + if (ret) { + dev_err(dev, "Failed to request irq %d\n", irq); + return ret; + } + + girq = &awi->gpio.irq; + gpio_irq_chip_set_chip(girq, &aw9523_irq_chip); + girq->parent_handler = NULL; + girq->num_parents = 0; + girq->parents = NULL; + girq->default_type = IRQ_TYPE_EDGE_BOTH; + girq->handler = handle_simple_irq; + girq->threaded = true; + + return 0; +} + +static bool aw9523_is_reg_hole(unsigned int reg) +{ + return (reg > AW9523_REG_PORT_MODE(AW9523_PINS_PER_PORT) && + reg < AW9523_REG_SOFT_RESET) || + (reg > AW9523_REG_INTR_DIS(AW9523_PINS_PER_PORT) && + reg < AW9523_REG_CHIPID); +} + +static bool aw9523_readable_reg(struct device *dev, unsigned int reg) +{ + /* All available registers (minus holes) can be read */ + return !aw9523_is_reg_hole(reg); +} + +static bool aw9523_volatile_reg(struct device *dev, unsigned int reg) +{ + return aw9523_is_reg_hole(reg) || + reg == AW9523_REG_IN_STATE(0) || + reg == AW9523_REG_IN_STATE(AW9523_PINS_PER_PORT) || + reg == AW9523_REG_CHIPID || + reg == AW9523_REG_SOFT_RESET; +} + +static bool aw9523_writeable_reg(struct device *dev, unsigned int reg) +{ + return !aw9523_is_reg_hole(reg) && reg != AW9523_REG_CHIPID; +} + +static bool aw9523_precious_reg(struct device *dev, unsigned int reg) +{ + /* Reading AW9523_REG_IN_STATE clears interrupt status */ + return aw9523_is_reg_hole(reg) || + reg == AW9523_REG_IN_STATE(0) || + reg == AW9523_REG_IN_STATE(AW9523_PINS_PER_PORT); +} + +static const struct regmap_config aw9523_regmap = { + .reg_bits = 8, + .val_bits = 8, + .reg_stride = 1, + + .precious_reg = aw9523_precious_reg, + .readable_reg = aw9523_readable_reg, + .volatile_reg = aw9523_volatile_reg, + .writeable_reg = aw9523_writeable_reg, + + .cache_type = REGCACHE_FLAT, + .disable_locking = true, + + .num_reg_defaults_raw = AW9523_REG_SOFT_RESET, +}; + +static int aw9523_hw_init(struct aw9523 *awi) +{ + u8 p1_pin = AW9523_PINS_PER_PORT; + unsigned int val; + int ret; + + /* No register caching during initialization */ + regcache_cache_bypass(awi->regmap, true); + + /* Bring up the chip */ + ret = aw9523_hw_reset(awi); + if (ret) { + dev_err(awi->dev, "HW Reset failed: %d\n", ret); + return ret; + } + + /* + * This is the expected chip and it is running: it's time to + * set a safe default configuration in case the user doesn't + * configure (all of the available) pins in this chip. + * P.S.: The writes order doesn't matter. + */ + + /* Set all pins as GPIO */ + ret = regmap_write(awi->regmap, AW9523_REG_PORT_MODE(0), U8_MAX); + if (ret) + return ret; + ret = regmap_write(awi->regmap, AW9523_REG_PORT_MODE(p1_pin), U8_MAX); + if (ret) + return ret; + + /* Set Open-Drain mode on Port 0 (Port 1 is always P-P) */ + ret = regmap_write(awi->regmap, AW9523_REG_GCR, 0); + if (ret) + return ret; + + /* Set all pins as inputs */ + ret = regmap_write(awi->regmap, AW9523_REG_CONF_STATE(0), U8_MAX); + if (ret) + return ret; + ret = regmap_write(awi->regmap, AW9523_REG_CONF_STATE(p1_pin), U8_MAX); + if (ret) + return ret; + + /* Disable all interrupts to avoid unreasoned wakeups */ + ret = regmap_write(awi->regmap, AW9523_REG_INTR_DIS(0), U8_MAX); + if (ret) + return ret; + ret = regmap_write(awi->regmap, AW9523_REG_INTR_DIS(p1_pin), U8_MAX); + if (ret) + return ret; + + /* Clear setup-generated interrupts by performing a port state read */ + ret = aw9523_get_port_state(awi->regmap, 0, 0, &val); + if (ret) + return ret; + ret = aw9523_get_port_state(awi->regmap, p1_pin, 0, &val); + if (ret) + return ret; + + /* Everything went fine: activate and reinitialize register cache */ + regcache_cache_bypass(awi->regmap, false); + return regmap_reinit_cache(awi->regmap, &aw9523_regmap); +} + +static int aw9523_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct pinctrl_desc *pdesc; + struct aw9523 *awi; + int ret; + + awi = devm_kzalloc(dev, sizeof(*awi), GFP_KERNEL); + if (!awi) + return -ENOMEM; + + i2c_set_clientdata(client, awi); + + awi->dev = dev; + awi->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); + if (IS_ERR(awi->reset_gpio)) + return PTR_ERR(awi->reset_gpio); + gpiod_set_consumer_name(awi->reset_gpio, "aw9523 reset"); + + awi->regmap = devm_regmap_init_i2c(client, &aw9523_regmap); + if (IS_ERR(awi->regmap)) + return PTR_ERR(awi->regmap); + + awi->vio_vreg = devm_regulator_get_optional(dev, "vio"); + if (IS_ERR(awi->vio_vreg)) { + if (PTR_ERR(awi->vio_vreg) == -EPROBE_DEFER) + return -EPROBE_DEFER; + awi->vio_vreg = NULL; + } else { + ret = regulator_enable(awi->vio_vreg); + if (ret) + return ret; + } + + mutex_init(&awi->i2c_lock); + lockdep_set_subclass(&awi->i2c_lock, + i2c_adapter_depth(client->adapter)); + + pdesc = devm_kzalloc(dev, sizeof(*pdesc), GFP_KERNEL); + if (!pdesc) + return -ENOMEM; + + ret = aw9523_hw_init(awi); + if (ret) + goto err_disable_vregs; + + pdesc->name = dev_name(dev); + pdesc->owner = THIS_MODULE; + pdesc->pctlops = &aw9523_pinctrl_ops; + pdesc->pmxops = &aw9523_pinmux_ops; + pdesc->confops = &aw9523_pinconf_ops; + pdesc->pins = aw9523_pins; + pdesc->npins = ARRAY_SIZE(aw9523_pins); + + ret = aw9523_init_gpiochip(awi, pdesc->npins); + if (ret) + goto err_disable_vregs; + + if (client->irq) { + ret = aw9523_init_irq(awi, client->irq); + if (ret) + goto err_disable_vregs; + } + + awi->pctl = devm_pinctrl_register(dev, pdesc, awi); + if (IS_ERR(awi->pctl)) { + ret = PTR_ERR(awi->pctl); + dev_err(dev, "Cannot register pinctrl: %d", ret); + goto err_disable_vregs; + } + + ret = devm_gpiochip_add_data(dev, &awi->gpio, awi); + if (ret) + goto err_disable_vregs; + + return ret; + +err_disable_vregs: + if (awi->vio_vreg) + regulator_disable(awi->vio_vreg); + mutex_destroy(&awi->i2c_lock); + return ret; +} + +static void aw9523_remove(struct i2c_client *client) +{ + struct aw9523 *awi = i2c_get_clientdata(client); + int ret; + + if (!awi) + return; + + /* + * If the chip VIO is connected to a regulator that we can turn + * off, life is easy... otherwise, reinitialize the chip and + * set the pins to hardware defaults before removing the driver + * to leave it in a clean, safe and predictable state. + */ + if (awi->vio_vreg) { + regulator_disable(awi->vio_vreg); + } else { + mutex_lock(&awi->i2c_lock); + ret = aw9523_hw_init(awi); + mutex_unlock(&awi->i2c_lock); + if (ret) + return; + } + + mutex_destroy(&awi->i2c_lock); +} + +static const struct i2c_device_id aw9523_i2c_id_table[] = { + { "aw9523_i2c", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, aw9523_i2c_id_table); + +static const struct of_device_id of_aw9523_i2c_match[] = { + { .compatible = "awinic,aw9523-pinctrl", }, + { } +}; +MODULE_DEVICE_TABLE(of, of_aw9523_i2c_match); + +static struct i2c_driver aw9523_driver = { + .driver = { + .name = "aw9523-pinctrl", + .of_match_table = of_aw9523_i2c_match, + }, + .probe = aw9523_probe, + .remove = aw9523_remove, + .id_table = aw9523_i2c_id_table, +}; +module_i2c_driver(aw9523_driver); + +MODULE_DESCRIPTION("Awinic AW9523 I2C GPIO Expander driver"); +MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>"); +MODULE_LICENSE("GPL v2"); |