diff options
Diffstat (limited to 'drivers/pinctrl/pinctrl-mcp23s08.c')
-rw-r--r-- | drivers/pinctrl/pinctrl-mcp23s08.c | 643 |
1 files changed, 643 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinctrl-mcp23s08.c b/drivers/pinctrl/pinctrl-mcp23s08.c new file mode 100644 index 000000000..5f356edfd --- /dev/null +++ b/drivers/pinctrl/pinctrl-mcp23s08.c @@ -0,0 +1,643 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* MCP23S08 SPI/I2C GPIO driver */ + +#include <linux/bitops.h> +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/mutex.h> +#include <linux/mod_devicetable.h> +#include <linux/module.h> +#include <linux/export.h> +#include <linux/gpio/driver.h> +#include <linux/gpio/consumer.h> +#include <linux/slab.h> +#include <asm/byteorder.h> +#include <linux/interrupt.h> +#include <linux/regmap.h> +#include <linux/pinctrl/pinctrl.h> +#include <linux/pinctrl/pinconf.h> +#include <linux/pinctrl/pinconf-generic.h> + +#include "pinctrl-mcp23s08.h" + +/* Registers are all 8 bits wide. + * + * The mcp23s17 has twice as many bits, and can be configured to work + * with either 16 bit registers or with two adjacent 8 bit banks. + */ +#define MCP_IODIR 0x00 /* init/reset: all ones */ +#define MCP_IPOL 0x01 +#define MCP_GPINTEN 0x02 +#define MCP_DEFVAL 0x03 +#define MCP_INTCON 0x04 +#define MCP_IOCON 0x05 +# define IOCON_MIRROR (1 << 6) +# define IOCON_SEQOP (1 << 5) +# define IOCON_HAEN (1 << 3) +# define IOCON_ODR (1 << 2) +# define IOCON_INTPOL (1 << 1) +# define IOCON_INTCC (1) +#define MCP_GPPU 0x06 +#define MCP_INTF 0x07 +#define MCP_INTCAP 0x08 +#define MCP_GPIO 0x09 +#define MCP_OLAT 0x0a + +static const struct reg_default mcp23x08_defaults[] = { + {.reg = MCP_IODIR, .def = 0xff}, + {.reg = MCP_IPOL, .def = 0x00}, + {.reg = MCP_GPINTEN, .def = 0x00}, + {.reg = MCP_DEFVAL, .def = 0x00}, + {.reg = MCP_INTCON, .def = 0x00}, + {.reg = MCP_IOCON, .def = 0x00}, + {.reg = MCP_GPPU, .def = 0x00}, + {.reg = MCP_OLAT, .def = 0x00}, +}; + +static const struct regmap_range mcp23x08_volatile_range = { + .range_min = MCP_INTF, + .range_max = MCP_GPIO, +}; + +static const struct regmap_access_table mcp23x08_volatile_table = { + .yes_ranges = &mcp23x08_volatile_range, + .n_yes_ranges = 1, +}; + +static const struct regmap_range mcp23x08_precious_range = { + .range_min = MCP_GPIO, + .range_max = MCP_GPIO, +}; + +static const struct regmap_access_table mcp23x08_precious_table = { + .yes_ranges = &mcp23x08_precious_range, + .n_yes_ranges = 1, +}; + +const struct regmap_config mcp23x08_regmap = { + .reg_bits = 8, + .val_bits = 8, + + .reg_stride = 1, + .volatile_table = &mcp23x08_volatile_table, + .precious_table = &mcp23x08_precious_table, + .reg_defaults = mcp23x08_defaults, + .num_reg_defaults = ARRAY_SIZE(mcp23x08_defaults), + .cache_type = REGCACHE_FLAT, + .max_register = MCP_OLAT, +}; +EXPORT_SYMBOL_GPL(mcp23x08_regmap); + +static const struct reg_default mcp23x17_defaults[] = { + {.reg = MCP_IODIR << 1, .def = 0xffff}, + {.reg = MCP_IPOL << 1, .def = 0x0000}, + {.reg = MCP_GPINTEN << 1, .def = 0x0000}, + {.reg = MCP_DEFVAL << 1, .def = 0x0000}, + {.reg = MCP_INTCON << 1, .def = 0x0000}, + {.reg = MCP_IOCON << 1, .def = 0x0000}, + {.reg = MCP_GPPU << 1, .def = 0x0000}, + {.reg = MCP_OLAT << 1, .def = 0x0000}, +}; + +static const struct regmap_range mcp23x17_volatile_range = { + .range_min = MCP_INTF << 1, + .range_max = MCP_GPIO << 1, +}; + +static const struct regmap_access_table mcp23x17_volatile_table = { + .yes_ranges = &mcp23x17_volatile_range, + .n_yes_ranges = 1, +}; + +static const struct regmap_range mcp23x17_precious_range = { + .range_min = MCP_INTCAP << 1, + .range_max = MCP_GPIO << 1, +}; + +static const struct regmap_access_table mcp23x17_precious_table = { + .yes_ranges = &mcp23x17_precious_range, + .n_yes_ranges = 1, +}; + +const struct regmap_config mcp23x17_regmap = { + .reg_bits = 8, + .val_bits = 16, + + .reg_stride = 2, + .max_register = MCP_OLAT << 1, + .volatile_table = &mcp23x17_volatile_table, + .precious_table = &mcp23x17_precious_table, + .reg_defaults = mcp23x17_defaults, + .num_reg_defaults = ARRAY_SIZE(mcp23x17_defaults), + .cache_type = REGCACHE_FLAT, + .val_format_endian = REGMAP_ENDIAN_LITTLE, +}; +EXPORT_SYMBOL_GPL(mcp23x17_regmap); + +static int mcp_read(struct mcp23s08 *mcp, unsigned int reg, unsigned int *val) +{ + return regmap_read(mcp->regmap, reg << mcp->reg_shift, val); +} + +static int mcp_write(struct mcp23s08 *mcp, unsigned int reg, unsigned int val) +{ + return regmap_write(mcp->regmap, reg << mcp->reg_shift, val); +} + +static int mcp_set_mask(struct mcp23s08 *mcp, unsigned int reg, + unsigned int mask, bool enabled) +{ + u16 val = enabled ? 0xffff : 0x0000; + return regmap_update_bits(mcp->regmap, reg << mcp->reg_shift, + mask, val); +} + +static int mcp_set_bit(struct mcp23s08 *mcp, unsigned int reg, + unsigned int pin, bool enabled) +{ + u16 mask = BIT(pin); + return mcp_set_mask(mcp, reg, mask, enabled); +} + +static const struct pinctrl_pin_desc mcp23x08_pins[] = { + 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"), +}; + +static const struct pinctrl_pin_desc mcp23x17_pins[] = { + 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"), + 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 mcp_pinctrl_get_groups_count(struct pinctrl_dev *pctldev) +{ + return 0; +} + +static const char *mcp_pinctrl_get_group_name(struct pinctrl_dev *pctldev, + unsigned int group) +{ + return NULL; +} + +static int mcp_pinctrl_get_group_pins(struct pinctrl_dev *pctldev, + unsigned int group, + const unsigned int **pins, + unsigned int *num_pins) +{ + return -ENOTSUPP; +} + +static const struct pinctrl_ops mcp_pinctrl_ops = { + .get_groups_count = mcp_pinctrl_get_groups_count, + .get_group_name = mcp_pinctrl_get_group_name, + .get_group_pins = mcp_pinctrl_get_group_pins, +#ifdef CONFIG_OF + .dt_node_to_map = pinconf_generic_dt_node_to_map_pin, + .dt_free_map = pinconf_generic_dt_free_map, +#endif +}; + +static int mcp_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin, + unsigned long *config) +{ + struct mcp23s08 *mcp = pinctrl_dev_get_drvdata(pctldev); + enum pin_config_param param = pinconf_to_config_param(*config); + unsigned int data, status; + int ret; + + switch (param) { + case PIN_CONFIG_BIAS_PULL_UP: + ret = mcp_read(mcp, MCP_GPPU, &data); + if (ret < 0) + return ret; + status = (data & BIT(pin)) ? 1 : 0; + break; + default: + return -ENOTSUPP; + } + + *config = 0; + + return status ? 0 : -EINVAL; +} + +static int mcp_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin, + unsigned long *configs, unsigned int num_configs) +{ + struct mcp23s08 *mcp = pinctrl_dev_get_drvdata(pctldev); + enum pin_config_param param; + u32 arg; + int ret = 0; + int i; + + for (i = 0; i < num_configs; i++) { + param = pinconf_to_config_param(configs[i]); + arg = pinconf_to_config_argument(configs[i]); + + switch (param) { + case PIN_CONFIG_BIAS_PULL_UP: + ret = mcp_set_bit(mcp, MCP_GPPU, pin, arg); + break; + default: + dev_dbg(mcp->dev, "Invalid config param %04x\n", param); + return -ENOTSUPP; + } + } + + return ret; +} + +static const struct pinconf_ops mcp_pinconf_ops = { + .pin_config_get = mcp_pinconf_get, + .pin_config_set = mcp_pinconf_set, + .is_generic = true, +}; + +/*----------------------------------------------------------------------*/ + +static int mcp23s08_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct mcp23s08 *mcp = gpiochip_get_data(chip); + int status; + + mutex_lock(&mcp->lock); + status = mcp_set_bit(mcp, MCP_IODIR, offset, true); + mutex_unlock(&mcp->lock); + + return status; +} + +static int mcp23s08_get(struct gpio_chip *chip, unsigned offset) +{ + struct mcp23s08 *mcp = gpiochip_get_data(chip); + int status, ret; + + mutex_lock(&mcp->lock); + + /* REVISIT reading this clears any IRQ ... */ + ret = mcp_read(mcp, MCP_GPIO, &status); + if (ret < 0) + status = 0; + else { + mcp->cached_gpio = status; + status = !!(status & (1 << offset)); + } + + mutex_unlock(&mcp->lock); + return status; +} + +static int __mcp23s08_set(struct mcp23s08 *mcp, unsigned mask, bool value) +{ + return mcp_set_mask(mcp, MCP_OLAT, mask, value); +} + +static void mcp23s08_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct mcp23s08 *mcp = gpiochip_get_data(chip); + unsigned mask = BIT(offset); + + mutex_lock(&mcp->lock); + __mcp23s08_set(mcp, mask, !!value); + mutex_unlock(&mcp->lock); +} + +static int +mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value) +{ + struct mcp23s08 *mcp = gpiochip_get_data(chip); + unsigned mask = BIT(offset); + int status; + + mutex_lock(&mcp->lock); + status = __mcp23s08_set(mcp, mask, value); + if (status == 0) { + status = mcp_set_mask(mcp, MCP_IODIR, mask, false); + } + mutex_unlock(&mcp->lock); + return status; +} + +/*----------------------------------------------------------------------*/ +static irqreturn_t mcp23s08_irq(int irq, void *data) +{ + struct mcp23s08 *mcp = data; + int intcap, intcon, intf, i, gpio, gpio_orig, intcap_mask, defval; + unsigned int child_irq; + bool intf_set, intcap_changed, gpio_bit_changed, + defval_changed, gpio_set; + + mutex_lock(&mcp->lock); + if (mcp_read(mcp, MCP_INTF, &intf)) + goto unlock; + + if (intf == 0) { + /* There is no interrupt pending */ + goto unlock; + } + + if (mcp_read(mcp, MCP_INTCAP, &intcap)) + goto unlock; + + if (mcp_read(mcp, MCP_INTCON, &intcon)) + goto unlock; + + if (mcp_read(mcp, MCP_DEFVAL, &defval)) + goto unlock; + + /* This clears the interrupt(configurable on S18) */ + if (mcp_read(mcp, MCP_GPIO, &gpio)) + goto unlock; + + gpio_orig = mcp->cached_gpio; + mcp->cached_gpio = gpio; + mutex_unlock(&mcp->lock); + + dev_dbg(mcp->chip.parent, + "intcap 0x%04X intf 0x%04X gpio_orig 0x%04X gpio 0x%04X\n", + intcap, intf, gpio_orig, gpio); + + for (i = 0; i < mcp->chip.ngpio; i++) { + /* We must check all of the inputs on the chip, + * otherwise we may not notice a change on >=2 pins. + * + * On at least the mcp23s17, INTCAP is only updated + * one byte at a time(INTCAPA and INTCAPB are + * not written to at the same time - only on a per-bank + * basis). + * + * INTF only contains the single bit that caused the + * interrupt per-bank. On the mcp23s17, there is + * INTFA and INTFB. If two pins are changed on the A + * side at the same time, INTF will only have one bit + * set. If one pin on the A side and one pin on the B + * side are changed at the same time, INTF will have + * two bits set. Thus, INTF can't be the only check + * to see if the input has changed. + */ + + intf_set = intf & BIT(i); + if (i < 8 && intf_set) + intcap_mask = 0x00FF; + else if (i >= 8 && intf_set) + intcap_mask = 0xFF00; + else + intcap_mask = 0x00; + + intcap_changed = (intcap_mask & + (intcap & BIT(i))) != + (intcap_mask & (BIT(i) & gpio_orig)); + gpio_set = BIT(i) & gpio; + gpio_bit_changed = (BIT(i) & gpio_orig) != + (BIT(i) & gpio); + defval_changed = (BIT(i) & intcon) && + ((BIT(i) & gpio) != + (BIT(i) & defval)); + + if (((gpio_bit_changed || intcap_changed) && + (BIT(i) & mcp->irq_rise) && gpio_set) || + ((gpio_bit_changed || intcap_changed) && + (BIT(i) & mcp->irq_fall) && !gpio_set) || + defval_changed) { + child_irq = irq_find_mapping(mcp->chip.irq.domain, i); + handle_nested_irq(child_irq); + } + } + + return IRQ_HANDLED; + +unlock: + mutex_unlock(&mcp->lock); + return IRQ_HANDLED; +} + +static void mcp23s08_irq_mask(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct mcp23s08 *mcp = gpiochip_get_data(gc); + unsigned int pos = data->hwirq; + + mcp_set_bit(mcp, MCP_GPINTEN, pos, false); +} + +static void mcp23s08_irq_unmask(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct mcp23s08 *mcp = gpiochip_get_data(gc); + unsigned int pos = data->hwirq; + + mcp_set_bit(mcp, MCP_GPINTEN, pos, true); +} + +static int mcp23s08_irq_set_type(struct irq_data *data, unsigned int type) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct mcp23s08 *mcp = gpiochip_get_data(gc); + unsigned int pos = data->hwirq; + + if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) { + mcp_set_bit(mcp, MCP_INTCON, pos, false); + mcp->irq_rise |= BIT(pos); + mcp->irq_fall |= BIT(pos); + } else if (type & IRQ_TYPE_EDGE_RISING) { + mcp_set_bit(mcp, MCP_INTCON, pos, false); + mcp->irq_rise |= BIT(pos); + mcp->irq_fall &= ~BIT(pos); + } else if (type & IRQ_TYPE_EDGE_FALLING) { + mcp_set_bit(mcp, MCP_INTCON, pos, false); + mcp->irq_rise &= ~BIT(pos); + mcp->irq_fall |= BIT(pos); + } else if (type & IRQ_TYPE_LEVEL_HIGH) { + mcp_set_bit(mcp, MCP_INTCON, pos, true); + mcp_set_bit(mcp, MCP_DEFVAL, pos, false); + } else if (type & IRQ_TYPE_LEVEL_LOW) { + mcp_set_bit(mcp, MCP_INTCON, pos, true); + mcp_set_bit(mcp, MCP_DEFVAL, pos, true); + } else + return -EINVAL; + + return 0; +} + +static void mcp23s08_irq_bus_lock(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct mcp23s08 *mcp = gpiochip_get_data(gc); + + mutex_lock(&mcp->lock); + regcache_cache_only(mcp->regmap, true); +} + +static void mcp23s08_irq_bus_unlock(struct irq_data *data) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct mcp23s08 *mcp = gpiochip_get_data(gc); + + regcache_cache_only(mcp->regmap, false); + regcache_sync(mcp->regmap); + + mutex_unlock(&mcp->lock); +} + +static int mcp23s08_irq_setup(struct mcp23s08 *mcp) +{ + struct gpio_chip *chip = &mcp->chip; + int err; + unsigned long irqflags = IRQF_ONESHOT | IRQF_SHARED; + + if (mcp->irq_active_high) + irqflags |= IRQF_TRIGGER_HIGH; + else + irqflags |= IRQF_TRIGGER_LOW; + + err = devm_request_threaded_irq(chip->parent, mcp->irq, NULL, + mcp23s08_irq, + irqflags, dev_name(chip->parent), mcp); + if (err != 0) { + dev_err(chip->parent, "unable to request IRQ#%d: %d\n", + mcp->irq, err); + return err; + } + + return 0; +} + +/*----------------------------------------------------------------------*/ + +int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev, + unsigned int addr, unsigned int type, unsigned int base) +{ + int status, ret; + bool mirror = false; + bool open_drain = false; + + mutex_init(&mcp->lock); + + mcp->dev = dev; + mcp->addr = addr; + + mcp->irq_active_high = false; + mcp->irq_chip.name = dev_name(dev); + mcp->irq_chip.irq_mask = mcp23s08_irq_mask; + mcp->irq_chip.irq_unmask = mcp23s08_irq_unmask; + mcp->irq_chip.irq_set_type = mcp23s08_irq_set_type; + mcp->irq_chip.irq_bus_lock = mcp23s08_irq_bus_lock; + mcp->irq_chip.irq_bus_sync_unlock = mcp23s08_irq_bus_unlock; + + mcp->chip.direction_input = mcp23s08_direction_input; + mcp->chip.get = mcp23s08_get; + mcp->chip.direction_output = mcp23s08_direction_output; + mcp->chip.set = mcp23s08_set; + + mcp->chip.base = base; + mcp->chip.can_sleep = true; + mcp->chip.parent = dev; + mcp->chip.owner = THIS_MODULE; + + mcp->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); + + /* verify MCP_IOCON.SEQOP = 0, so sequential reads work, + * and MCP_IOCON.HAEN = 1, so we work with all chips. + */ + + ret = mcp_read(mcp, MCP_IOCON, &status); + if (ret < 0) + return dev_err_probe(dev, ret, "can't identify chip %d\n", addr); + + mcp->irq_controller = + device_property_read_bool(dev, "interrupt-controller"); + if (mcp->irq && mcp->irq_controller) { + mcp->irq_active_high = + device_property_read_bool(dev, + "microchip,irq-active-high"); + + mirror = device_property_read_bool(dev, "microchip,irq-mirror"); + open_drain = device_property_read_bool(dev, "drive-open-drain"); + } + + if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror || + mcp->irq_active_high || open_drain) { + /* mcp23s17 has IOCON twice, make sure they are in sync */ + status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8)); + status |= IOCON_HAEN | (IOCON_HAEN << 8); + if (mcp->irq_active_high) + status |= IOCON_INTPOL | (IOCON_INTPOL << 8); + else + status &= ~(IOCON_INTPOL | (IOCON_INTPOL << 8)); + + if (mirror) + status |= IOCON_MIRROR | (IOCON_MIRROR << 8); + + if (open_drain) + status |= IOCON_ODR | (IOCON_ODR << 8); + + if (type == MCP_TYPE_S18 || type == MCP_TYPE_018) + status |= IOCON_INTCC | (IOCON_INTCC << 8); + + ret = mcp_write(mcp, MCP_IOCON, status); + if (ret < 0) + return dev_err_probe(dev, ret, "can't write IOCON %d\n", addr); + } + + if (mcp->irq && mcp->irq_controller) { + struct gpio_irq_chip *girq = &mcp->chip.irq; + + girq->chip = &mcp->irq_chip; + /* This will let us handle the parent IRQ in the driver */ + girq->parent_handler = NULL; + girq->num_parents = 0; + girq->parents = NULL; + girq->default_type = IRQ_TYPE_NONE; + girq->handler = handle_simple_irq; + girq->threaded = true; + } + + ret = devm_gpiochip_add_data(dev, &mcp->chip, mcp); + if (ret < 0) + return dev_err_probe(dev, ret, "can't add GPIO chip\n"); + + mcp->pinctrl_desc.pctlops = &mcp_pinctrl_ops; + mcp->pinctrl_desc.confops = &mcp_pinconf_ops; + mcp->pinctrl_desc.npins = mcp->chip.ngpio; + if (mcp->pinctrl_desc.npins == 8) + mcp->pinctrl_desc.pins = mcp23x08_pins; + else if (mcp->pinctrl_desc.npins == 16) + mcp->pinctrl_desc.pins = mcp23x17_pins; + mcp->pinctrl_desc.owner = THIS_MODULE; + + mcp->pctldev = devm_pinctrl_register(dev, &mcp->pinctrl_desc, mcp); + if (IS_ERR(mcp->pctldev)) + return dev_err_probe(dev, PTR_ERR(mcp->pctldev), "can't register controller\n"); + + if (mcp->irq) { + ret = mcp23s08_irq_setup(mcp); + if (ret) + return dev_err_probe(dev, ret, "can't setup IRQ\n"); + } + + return 0; +} +EXPORT_SYMBOL_GPL(mcp23s08_probe_one); + +MODULE_LICENSE("GPL"); |