// SPDX-License-Identifier: GPL-2.0-only /* * MAX732x I2C Port Expander with 8/16 I/O * * Copyright (C) 2007 Marvell International Ltd. * Copyright (C) 2008 Jack Ren <jack.ren@marvell.com> * Copyright (C) 2008 Eric Miao <eric.miao@marvell.com> * Copyright (C) 2015 Linus Walleij <linus.walleij@linaro.org> * * Derived from drivers/gpio/pca953x.c */ #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/gpio/driver.h> #include <linux/interrupt.h> #include <linux/i2c.h> #include <linux/platform_data/max732x.h> #include <linux/of.h> /* * Each port of MAX732x (including MAX7319) falls into one of the * following three types: * * - Push Pull Output * - Input * - Open Drain I/O * * designated by 'O', 'I' and 'P' individually according to MAXIM's * datasheets. 'I' and 'P' ports are interrupt capables, some with * a dedicated interrupt mask. * * There are two groups of I/O ports, each group usually includes * up to 8 I/O ports, and is accessed by a specific I2C address: * * - Group A : by I2C address 0b'110xxxx * - Group B : by I2C address 0b'101xxxx * * where 'xxxx' is decided by the connections of pin AD2/AD0. The * address used also affects the initial state of output signals. * * Within each group of ports, there are five known combinations of * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for * the detailed organization of these ports. Only Goup A is interrupt * capable. * * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16', * and GPIOs from GROUP_A are numbered before those from GROUP_B * (if there are two groups). * * NOTE: MAX7328/MAX7329 are drop-in replacements for PCF8574/a, so * they are not supported by this driver. */ #define PORT_NONE 0x0 /* '/' No Port */ #define PORT_OUTPUT 0x1 /* 'O' Push-Pull, Output Only */ #define PORT_INPUT 0x2 /* 'I' Input Only */ #define PORT_OPENDRAIN 0x3 /* 'P' Open-Drain, I/O */ #define IO_4I4O 0x5AA5 /* O7 O6 I5 I4 I3 I2 O1 O0 */ #define IO_4P4O 0x5FF5 /* O7 O6 P5 P4 P3 P2 O1 O0 */ #define IO_8I 0xAAAA /* I7 I6 I5 I4 I3 I2 I1 I0 */ #define IO_8P 0xFFFF /* P7 P6 P5 P4 P3 P2 P1 P0 */ #define IO_8O 0x5555 /* O7 O6 O5 O4 O3 O2 O1 O0 */ #define GROUP_A(x) ((x) & 0xffff) /* I2C Addr: 0b'110xxxx */ #define GROUP_B(x) ((x) << 16) /* I2C Addr: 0b'101xxxx */ #define INT_NONE 0x0 /* No interrupt capability */ #define INT_NO_MASK 0x1 /* Has interrupts, no mask */ #define INT_INDEP_MASK 0x2 /* Has interrupts, independent mask */ #define INT_MERGED_MASK 0x3 /* Has interrupts, merged mask */ #define INT_CAPS(x) (((uint64_t)(x)) << 32) enum { MAX7319, MAX7320, MAX7321, MAX7322, MAX7323, MAX7324, MAX7325, MAX7326, MAX7327, }; static uint64_t max732x_features[] = { [MAX7319] = GROUP_A(IO_8I) | INT_CAPS(INT_MERGED_MASK), [MAX7320] = GROUP_B(IO_8O), [MAX7321] = GROUP_A(IO_8P) | INT_CAPS(INT_NO_MASK), [MAX7322] = GROUP_A(IO_4I4O) | INT_CAPS(INT_MERGED_MASK), [MAX7323] = GROUP_A(IO_4P4O) | INT_CAPS(INT_INDEP_MASK), [MAX7324] = GROUP_A(IO_8I) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK), [MAX7325] = GROUP_A(IO_8P) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK), [MAX7326] = GROUP_A(IO_4I4O) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK), [MAX7327] = GROUP_A(IO_4P4O) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK), }; static const struct i2c_device_id max732x_id[] = { { "max7319", MAX7319 }, { "max7320", MAX7320 }, { "max7321", MAX7321 }, { "max7322", MAX7322 }, { "max7323", MAX7323 }, { "max7324", MAX7324 }, { "max7325", MAX7325 }, { "max7326", MAX7326 }, { "max7327", MAX7327 }, { }, }; MODULE_DEVICE_TABLE(i2c, max732x_id); #ifdef CONFIG_OF static const struct of_device_id max732x_of_table[] = { { .compatible = "maxim,max7319" }, { .compatible = "maxim,max7320" }, { .compatible = "maxim,max7321" }, { .compatible = "maxim,max7322" }, { .compatible = "maxim,max7323" }, { .compatible = "maxim,max7324" }, { .compatible = "maxim,max7325" }, { .compatible = "maxim,max7326" }, { .compatible = "maxim,max7327" }, { } }; MODULE_DEVICE_TABLE(of, max732x_of_table); #endif struct max732x_chip { struct gpio_chip gpio_chip; struct i2c_client *client; /* "main" client */ struct i2c_client *client_dummy; struct i2c_client *client_group_a; struct i2c_client *client_group_b; unsigned int mask_group_a; unsigned int dir_input; unsigned int dir_output; struct mutex lock; uint8_t reg_out[2]; #ifdef CONFIG_GPIO_MAX732X_IRQ struct mutex irq_lock; uint8_t irq_mask; uint8_t irq_mask_cur; uint8_t irq_trig_raise; uint8_t irq_trig_fall; uint8_t irq_features; #endif }; static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val) { struct i2c_client *client; int ret; client = group_a ? chip->client_group_a : chip->client_group_b; ret = i2c_smbus_write_byte(client, val); if (ret < 0) { dev_err(&client->dev, "failed writing\n"); return ret; } return 0; } static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val) { struct i2c_client *client; int ret; client = group_a ? chip->client_group_a : chip->client_group_b; ret = i2c_smbus_read_byte(client); if (ret < 0) { dev_err(&client->dev, "failed reading\n"); return ret; } *val = (uint8_t)ret; return 0; } static inline int is_group_a(struct max732x_chip *chip, unsigned off) { return (1u << off) & chip->mask_group_a; } static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off) { struct max732x_chip *chip = gpiochip_get_data(gc); uint8_t reg_val; int ret; ret = max732x_readb(chip, is_group_a(chip, off), ®_val); if (ret < 0) return ret; return !!(reg_val & (1u << (off & 0x7))); } static void max732x_gpio_set_mask(struct gpio_chip *gc, unsigned off, int mask, int val) { struct max732x_chip *chip = gpiochip_get_data(gc); uint8_t reg_out; int ret; mutex_lock(&chip->lock); reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0]; reg_out = (reg_out & ~mask) | (val & mask); ret = max732x_writeb(chip, is_group_a(chip, off), reg_out); if (ret < 0) goto out; /* update the shadow register then */ if (off > 7) chip->reg_out[1] = reg_out; else chip->reg_out[0] = reg_out; out: mutex_unlock(&chip->lock); } static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val) { unsigned base = off & ~0x7; uint8_t mask = 1u << (off & 0x7); max732x_gpio_set_mask(gc, base, mask, val << (off & 0x7)); } static void max732x_gpio_set_multiple(struct gpio_chip *gc, unsigned long *mask, unsigned long *bits) { unsigned mask_lo = mask[0] & 0xff; unsigned mask_hi = (mask[0] >> 8) & 0xff; if (mask_lo) max732x_gpio_set_mask(gc, 0, mask_lo, bits[0] & 0xff); if (mask_hi) max732x_gpio_set_mask(gc, 8, mask_hi, (bits[0] >> 8) & 0xff); } static int max732x_gpio_direction_input(struct gpio_chip *gc, unsigned off) { struct max732x_chip *chip = gpiochip_get_data(gc); unsigned int mask = 1u << off; if ((mask & chip->dir_input) == 0) { dev_dbg(&chip->client->dev, "%s port %d is output only\n", chip->client->name, off); return -EACCES; } /* * Open-drain pins must be set to high impedance (which is * equivalent to output-high) to be turned into an input. */ if ((mask & chip->dir_output)) max732x_gpio_set_value(gc, off, 1); return 0; } static int max732x_gpio_direction_output(struct gpio_chip *gc, unsigned off, int val) { struct max732x_chip *chip = gpiochip_get_data(gc); unsigned int mask = 1u << off; if ((mask & chip->dir_output) == 0) { dev_dbg(&chip->client->dev, "%s port %d is input only\n", chip->client->name, off); return -EACCES; } max732x_gpio_set_value(gc, off, val); return 0; } #ifdef CONFIG_GPIO_MAX732X_IRQ static int max732x_writew(struct max732x_chip *chip, uint16_t val) { int ret; val = cpu_to_le16(val); ret = i2c_master_send(chip->client_group_a, (char *)&val, 2); if (ret < 0) { dev_err(&chip->client_group_a->dev, "failed writing\n"); return ret; } return 0; } static int max732x_readw(struct max732x_chip *chip, uint16_t *val) { int ret; ret = i2c_master_recv(chip->client_group_a, (char *)val, 2); if (ret < 0) { dev_err(&chip->client_group_a->dev, "failed reading\n"); return ret; } *val = le16_to_cpu(*val); return 0; } static void max732x_irq_update_mask(struct max732x_chip *chip) { uint16_t msg; if (chip->irq_mask == chip->irq_mask_cur) return; chip->irq_mask = chip->irq_mask_cur; if (chip->irq_features == INT_NO_MASK) return; mutex_lock(&chip->lock); switch (chip->irq_features) { case INT_INDEP_MASK: msg = (chip->irq_mask << 8) | chip->reg_out[0]; max732x_writew(chip, msg); break; case INT_MERGED_MASK: msg = chip->irq_mask | chip->reg_out[0]; max732x_writeb(chip, 1, (uint8_t)msg); break; } mutex_unlock(&chip->lock); } static void max732x_irq_mask(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct max732x_chip *chip = gpiochip_get_data(gc); chip->irq_mask_cur &= ~(1 << d->hwirq); } static void max732x_irq_unmask(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct max732x_chip *chip = gpiochip_get_data(gc); chip->irq_mask_cur |= 1 << d->hwirq; } static void max732x_irq_bus_lock(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct max732x_chip *chip = gpiochip_get_data(gc); mutex_lock(&chip->irq_lock); chip->irq_mask_cur = chip->irq_mask; } static void max732x_irq_bus_sync_unlock(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct max732x_chip *chip = gpiochip_get_data(gc); uint16_t new_irqs; uint16_t level; max732x_irq_update_mask(chip); new_irqs = chip->irq_trig_fall | chip->irq_trig_raise; while (new_irqs) { level = __ffs(new_irqs); max732x_gpio_direction_input(&chip->gpio_chip, level); new_irqs &= ~(1 << level); } mutex_unlock(&chip->irq_lock); } static int max732x_irq_set_type(struct irq_data *d, unsigned int type) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct max732x_chip *chip = gpiochip_get_data(gc); uint16_t off = d->hwirq; uint16_t mask = 1 << off; if (!(mask & chip->dir_input)) { dev_dbg(&chip->client->dev, "%s port %d is output only\n", chip->client->name, off); return -EACCES; } if (!(type & IRQ_TYPE_EDGE_BOTH)) { dev_err(&chip->client->dev, "irq %d: unsupported type %d\n", d->irq, type); return -EINVAL; } if (type & IRQ_TYPE_EDGE_FALLING) chip->irq_trig_fall |= mask; else chip->irq_trig_fall &= ~mask; if (type & IRQ_TYPE_EDGE_RISING) chip->irq_trig_raise |= mask; else chip->irq_trig_raise &= ~mask; return 0; } static int max732x_irq_set_wake(struct irq_data *data, unsigned int on) { struct max732x_chip *chip = irq_data_get_irq_chip_data(data); irq_set_irq_wake(chip->client->irq, on); return 0; } static struct irq_chip max732x_irq_chip = { .name = "max732x", .irq_mask = max732x_irq_mask, .irq_unmask = max732x_irq_unmask, .irq_bus_lock = max732x_irq_bus_lock, .irq_bus_sync_unlock = max732x_irq_bus_sync_unlock, .irq_set_type = max732x_irq_set_type, .irq_set_wake = max732x_irq_set_wake, }; static uint8_t max732x_irq_pending(struct max732x_chip *chip) { uint8_t cur_stat; uint8_t old_stat; uint8_t trigger; uint8_t pending; uint16_t status; int ret; ret = max732x_readw(chip, &status); if (ret) return 0; trigger = status >> 8; trigger &= chip->irq_mask; if (!trigger) return 0; cur_stat = status & 0xFF; cur_stat &= chip->irq_mask; old_stat = cur_stat ^ trigger; pending = (old_stat & chip->irq_trig_fall) | (cur_stat & chip->irq_trig_raise); pending &= trigger; return pending; } static irqreturn_t max732x_irq_handler(int irq, void *devid) { struct max732x_chip *chip = devid; uint8_t pending; uint8_t level; pending = max732x_irq_pending(chip); if (!pending) return IRQ_HANDLED; do { level = __ffs(pending); handle_nested_irq(irq_find_mapping(chip->gpio_chip.irq.domain, level)); pending &= ~(1 << level); } while (pending); return IRQ_HANDLED; } static int max732x_irq_setup(struct max732x_chip *chip, const struct i2c_device_id *id) { struct i2c_client *client = chip->client; struct max732x_platform_data *pdata = dev_get_platdata(&client->dev); int has_irq = max732x_features[id->driver_data] >> 32; int irq_base = 0; int ret; if (((pdata && pdata->irq_base) || client->irq) && has_irq != INT_NONE) { if (pdata) irq_base = pdata->irq_base; chip->irq_features = has_irq; mutex_init(&chip->irq_lock); ret = devm_request_threaded_irq(&client->dev, client->irq, NULL, max732x_irq_handler, IRQF_ONESHOT | IRQF_TRIGGER_FALLING | IRQF_SHARED, dev_name(&client->dev), chip); if (ret) { dev_err(&client->dev, "failed to request irq %d\n", client->irq); return ret; } ret = gpiochip_irqchip_add_nested(&chip->gpio_chip, &max732x_irq_chip, irq_base, handle_simple_irq, IRQ_TYPE_NONE); if (ret) { dev_err(&client->dev, "could not connect irqchip to gpiochip\n"); return ret; } gpiochip_set_nested_irqchip(&chip->gpio_chip, &max732x_irq_chip, client->irq); } return 0; } #else /* CONFIG_GPIO_MAX732X_IRQ */ static int max732x_irq_setup(struct max732x_chip *chip, const struct i2c_device_id *id) { struct i2c_client *client = chip->client; struct max732x_platform_data *pdata = dev_get_platdata(&client->dev); int has_irq = max732x_features[id->driver_data] >> 32; if (((pdata && pdata->irq_base) || client->irq) && has_irq != INT_NONE) dev_warn(&client->dev, "interrupt support not compiled in\n"); return 0; } #endif static int max732x_setup_gpio(struct max732x_chip *chip, const struct i2c_device_id *id, unsigned gpio_start) { struct gpio_chip *gc = &chip->gpio_chip; uint32_t id_data = (uint32_t)max732x_features[id->driver_data]; int i, port = 0; for (i = 0; i < 16; i++, id_data >>= 2) { unsigned int mask = 1 << port; switch (id_data & 0x3) { case PORT_OUTPUT: chip->dir_output |= mask; break; case PORT_INPUT: chip->dir_input |= mask; break; case PORT_OPENDRAIN: chip->dir_output |= mask; chip->dir_input |= mask; break; default: continue; } if (i < 8) chip->mask_group_a |= mask; port++; } if (chip->dir_input) gc->direction_input = max732x_gpio_direction_input; if (chip->dir_output) { gc->direction_output = max732x_gpio_direction_output; gc->set = max732x_gpio_set_value; gc->set_multiple = max732x_gpio_set_multiple; } gc->get = max732x_gpio_get_value; gc->can_sleep = true; gc->base = gpio_start; gc->ngpio = port; gc->label = chip->client->name; gc->parent = &chip->client->dev; gc->owner = THIS_MODULE; return port; } static struct max732x_platform_data *of_gpio_max732x(struct device *dev) { struct max732x_platform_data *pdata; pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) return NULL; pdata->gpio_base = -1; return pdata; } static int max732x_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct max732x_platform_data *pdata; struct device_node *node; struct max732x_chip *chip; struct i2c_client *c; uint16_t addr_a, addr_b; int ret, nr_port; pdata = dev_get_platdata(&client->dev); node = client->dev.of_node; if (!pdata && node) pdata = of_gpio_max732x(&client->dev); if (!pdata) { dev_dbg(&client->dev, "no platform data\n"); return -EINVAL; } chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); if (chip == NULL) return -ENOMEM; chip->client = client; nr_port = max732x_setup_gpio(chip, id, pdata->gpio_base); chip->gpio_chip.parent = &client->dev; addr_a = (client->addr & 0x0f) | 0x60; addr_b = (client->addr & 0x0f) | 0x50; switch (client->addr & 0x70) { case 0x60: chip->client_group_a = client; if (nr_port > 8) { c = devm_i2c_new_dummy_device(&client->dev, client->adapter, addr_b); if (IS_ERR(c)) { dev_err(&client->dev, "Failed to allocate I2C device\n"); return PTR_ERR(c); } chip->client_group_b = chip->client_dummy = c; } break; case 0x50: chip->client_group_b = client; if (nr_port > 8) { c = devm_i2c_new_dummy_device(&client->dev, client->adapter, addr_a); if (IS_ERR(c)) { dev_err(&client->dev, "Failed to allocate I2C device\n"); return PTR_ERR(c); } chip->client_group_a = chip->client_dummy = c; } break; default: dev_err(&client->dev, "invalid I2C address specified %02x\n", client->addr); return -EINVAL; } if (nr_port > 8 && !chip->client_dummy) { dev_err(&client->dev, "Failed to allocate second group I2C device\n"); return -ENODEV; } mutex_init(&chip->lock); ret = max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]); if (ret) return ret; if (nr_port > 8) { ret = max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]); if (ret) return ret; } ret = devm_gpiochip_add_data(&client->dev, &chip->gpio_chip, chip); if (ret) return ret; ret = max732x_irq_setup(chip, id); if (ret) return ret; if (pdata && pdata->setup) { ret = pdata->setup(client, chip->gpio_chip.base, chip->gpio_chip.ngpio, pdata->context); if (ret < 0) dev_warn(&client->dev, "setup failed, %d\n", ret); } i2c_set_clientdata(client, chip); return 0; } static int max732x_remove(struct i2c_client *client) { struct max732x_platform_data *pdata = dev_get_platdata(&client->dev); struct max732x_chip *chip = i2c_get_clientdata(client); if (pdata && pdata->teardown) { int ret; ret = pdata->teardown(client, chip->gpio_chip.base, chip->gpio_chip.ngpio, pdata->context); if (ret < 0) { dev_err(&client->dev, "%s failed, %d\n", "teardown", ret); return ret; } } return 0; } static struct i2c_driver max732x_driver = { .driver = { .name = "max732x", .of_match_table = of_match_ptr(max732x_of_table), }, .probe = max732x_probe, .remove = max732x_remove, .id_table = max732x_id, }; static int __init max732x_init(void) { return i2c_add_driver(&max732x_driver); } /* register after i2c postcore initcall and before * subsys initcalls that may rely on these GPIOs */ subsys_initcall(max732x_init); static void __exit max732x_exit(void) { i2c_del_driver(&max732x_driver); } module_exit(max732x_exit); MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>"); MODULE_DESCRIPTION("GPIO expander driver for MAX732X"); MODULE_LICENSE("GPL");