| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright 2007-2008 Extreme Engineering Solutions, Inc. |
| * |
| * Author: Nate Case <ncase@xes-inc.com> |
| * |
| * LED driver for various PCA955x I2C LED drivers |
| * |
| * Supported devices: |
| * |
| * Device Description 7-bit slave address |
| * ------ ----------- ------------------- |
| * PCA9550 2-bit driver 0x60 .. 0x61 |
| * PCA9551 8-bit driver 0x60 .. 0x67 |
| * PCA9552 16-bit driver 0x60 .. 0x67 |
| * PCA9553/01 4-bit driver 0x62 |
| * PCA9553/02 4-bit driver 0x63 |
| * |
| * Philips PCA955x LED driver chips follow a register map as shown below: |
| * |
| * Control Register Description |
| * ---------------- ----------- |
| * 0x0 Input register 0 |
| * .. |
| * NUM_INPUT_REGS - 1 Last Input register X |
| * |
| * NUM_INPUT_REGS Frequency prescaler 0 |
| * NUM_INPUT_REGS + 1 PWM register 0 |
| * NUM_INPUT_REGS + 2 Frequency prescaler 1 |
| * NUM_INPUT_REGS + 3 PWM register 1 |
| * |
| * NUM_INPUT_REGS + 4 LED selector 0 |
| * NUM_INPUT_REGS + 4 |
| * + NUM_LED_REGS - 1 Last LED selector |
| * |
| * where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many |
| * bits the chip supports. |
| */ |
| |
| #include <linux/ctype.h> |
| #include <linux/delay.h> |
| #include <linux/err.h> |
| #include <linux/gpio/driver.h> |
| #include <linux/i2c.h> |
| #include <linux/leds.h> |
| #include <linux/module.h> |
| #include <linux/of.h> |
| #include <linux/property.h> |
| #include <linux/slab.h> |
| #include <linux/string.h> |
| |
| #include <dt-bindings/leds/leds-pca955x.h> |
| |
| /* LED select registers determine the source that drives LED outputs */ |
| #define PCA955X_LS_LED_ON 0x0 /* Output LOW */ |
| #define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */ |
| #define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */ |
| #define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */ |
| |
| #define PCA955X_GPIO_INPUT LED_OFF |
| #define PCA955X_GPIO_HIGH LED_OFF |
| #define PCA955X_GPIO_LOW LED_FULL |
| |
| enum pca955x_type { |
| pca9550, |
| pca9551, |
| pca9552, |
| ibm_pca9552, |
| pca9553, |
| }; |
| |
| struct pca955x_chipdef { |
| int bits; |
| u8 slv_addr; /* 7-bit slave address mask */ |
| int slv_addr_shift; /* Number of bits to ignore */ |
| }; |
| |
| static struct pca955x_chipdef pca955x_chipdefs[] = { |
| [pca9550] = { |
| .bits = 2, |
| .slv_addr = /* 110000x */ 0x60, |
| .slv_addr_shift = 1, |
| }, |
| [pca9551] = { |
| .bits = 8, |
| .slv_addr = /* 1100xxx */ 0x60, |
| .slv_addr_shift = 3, |
| }, |
| [pca9552] = { |
| .bits = 16, |
| .slv_addr = /* 1100xxx */ 0x60, |
| .slv_addr_shift = 3, |
| }, |
| [ibm_pca9552] = { |
| .bits = 16, |
| .slv_addr = /* 0110xxx */ 0x30, |
| .slv_addr_shift = 3, |
| }, |
| [pca9553] = { |
| .bits = 4, |
| .slv_addr = /* 110001x */ 0x62, |
| .slv_addr_shift = 1, |
| }, |
| }; |
| |
| static const struct i2c_device_id pca955x_id[] = { |
| { "pca9550", pca9550 }, |
| { "pca9551", pca9551 }, |
| { "pca9552", pca9552 }, |
| { "ibm-pca9552", ibm_pca9552 }, |
| { "pca9553", pca9553 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, pca955x_id); |
| |
| struct pca955x { |
| struct mutex lock; |
| struct pca955x_led *leds; |
| struct pca955x_chipdef *chipdef; |
| struct i2c_client *client; |
| #ifdef CONFIG_LEDS_PCA955X_GPIO |
| struct gpio_chip gpio; |
| #endif |
| }; |
| |
| struct pca955x_led { |
| struct pca955x *pca955x; |
| struct led_classdev led_cdev; |
| int led_num; /* 0 .. 15 potentially */ |
| u32 type; |
| int default_state; |
| struct fwnode_handle *fwnode; |
| }; |
| |
| struct pca955x_platform_data { |
| struct pca955x_led *leds; |
| int num_leds; |
| }; |
| |
| /* 8 bits per input register */ |
| static inline int pca95xx_num_input_regs(int bits) |
| { |
| return (bits + 7) / 8; |
| } |
| |
| /* 4 bits per LED selector register */ |
| static inline int pca95xx_num_led_regs(int bits) |
| { |
| return (bits + 3) / 4; |
| } |
| |
| /* |
| * Return an LED selector register value based on an existing one, with |
| * the appropriate 2-bit state value set for the given LED number (0-3). |
| */ |
| static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state) |
| { |
| return (oldval & (~(0x3 << (led_num << 1)))) | |
| ((state & 0x3) << (led_num << 1)); |
| } |
| |
| /* |
| * Write to frequency prescaler register, used to program the |
| * period of the PWM output. period = (PSCx + 1) / 38 |
| */ |
| static int pca955x_write_psc(struct i2c_client *client, int n, u8 val) |
| { |
| struct pca955x *pca955x = i2c_get_clientdata(client); |
| u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n); |
| int ret; |
| |
| ret = i2c_smbus_write_byte_data(client, cmd, val); |
| if (ret < 0) |
| dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", |
| __func__, n, val, ret); |
| return ret; |
| } |
| |
| /* |
| * Write to PWM register, which determines the duty cycle of the |
| * output. LED is OFF when the count is less than the value of this |
| * register, and ON when it is greater. If PWMx == 0, LED is always OFF. |
| * |
| * Duty cycle is (256 - PWMx) / 256 |
| */ |
| static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val) |
| { |
| struct pca955x *pca955x = i2c_get_clientdata(client); |
| u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n); |
| int ret; |
| |
| ret = i2c_smbus_write_byte_data(client, cmd, val); |
| if (ret < 0) |
| dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", |
| __func__, n, val, ret); |
| return ret; |
| } |
| |
| /* |
| * Write to LED selector register, which determines the source that |
| * drives the LED output. |
| */ |
| static int pca955x_write_ls(struct i2c_client *client, int n, u8 val) |
| { |
| struct pca955x *pca955x = i2c_get_clientdata(client); |
| u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n; |
| int ret; |
| |
| ret = i2c_smbus_write_byte_data(client, cmd, val); |
| if (ret < 0) |
| dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", |
| __func__, n, val, ret); |
| return ret; |
| } |
| |
| /* |
| * Read the LED selector register, which determines the source that |
| * drives the LED output. |
| */ |
| static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val) |
| { |
| struct pca955x *pca955x = i2c_get_clientdata(client); |
| u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n; |
| int ret; |
| |
| ret = i2c_smbus_read_byte_data(client, cmd); |
| if (ret < 0) { |
| dev_err(&client->dev, "%s: reg 0x%x, err %d\n", |
| __func__, n, ret); |
| return ret; |
| } |
| *val = (u8)ret; |
| return 0; |
| } |
| |
| static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val) |
| { |
| struct pca955x *pca955x = i2c_get_clientdata(client); |
| u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n); |
| int ret; |
| |
| ret = i2c_smbus_read_byte_data(client, cmd); |
| if (ret < 0) { |
| dev_err(&client->dev, "%s: reg 0x%x, err %d\n", |
| __func__, n, ret); |
| return ret; |
| } |
| *val = (u8)ret; |
| return 0; |
| } |
| |
| static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev) |
| { |
| struct pca955x_led *pca955x_led = container_of(led_cdev, |
| struct pca955x_led, |
| led_cdev); |
| struct pca955x *pca955x = pca955x_led->pca955x; |
| u8 ls, pwm; |
| int ret; |
| |
| ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls); |
| if (ret) |
| return ret; |
| |
| ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3; |
| switch (ls) { |
| case PCA955X_LS_LED_ON: |
| ret = LED_FULL; |
| break; |
| case PCA955X_LS_LED_OFF: |
| ret = LED_OFF; |
| break; |
| case PCA955X_LS_BLINK0: |
| ret = LED_HALF; |
| break; |
| case PCA955X_LS_BLINK1: |
| ret = pca955x_read_pwm(pca955x->client, 1, &pwm); |
| if (ret) |
| return ret; |
| ret = 255 - pwm; |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static int pca955x_led_set(struct led_classdev *led_cdev, |
| enum led_brightness value) |
| { |
| struct pca955x_led *pca955x_led; |
| struct pca955x *pca955x; |
| u8 ls; |
| int chip_ls; /* which LSx to use (0-3 potentially) */ |
| int ls_led; /* which set of bits within LSx to use (0-3) */ |
| int ret; |
| |
| pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev); |
| pca955x = pca955x_led->pca955x; |
| |
| chip_ls = pca955x_led->led_num / 4; |
| ls_led = pca955x_led->led_num % 4; |
| |
| mutex_lock(&pca955x->lock); |
| |
| ret = pca955x_read_ls(pca955x->client, chip_ls, &ls); |
| if (ret) |
| goto out; |
| |
| switch (value) { |
| case LED_FULL: |
| ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON); |
| break; |
| case LED_OFF: |
| ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF); |
| break; |
| case LED_HALF: |
| ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0); |
| break; |
| default: |
| /* |
| * Use PWM1 for all other values. This has the unwanted |
| * side effect of making all LEDs on the chip share the |
| * same brightness level if set to a value other than |
| * OFF, HALF, or FULL. But, this is probably better than |
| * just turning off for all other values. |
| */ |
| ret = pca955x_write_pwm(pca955x->client, 1, 255 - value); |
| if (ret) |
| goto out; |
| ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1); |
| break; |
| } |
| |
| ret = pca955x_write_ls(pca955x->client, chip_ls, ls); |
| |
| out: |
| mutex_unlock(&pca955x->lock); |
| |
| return ret; |
| } |
| |
| #ifdef CONFIG_LEDS_PCA955X_GPIO |
| /* |
| * Read the INPUT register, which contains the state of LEDs. |
| */ |
| static int pca955x_read_input(struct i2c_client *client, int n, u8 *val) |
| { |
| int ret = i2c_smbus_read_byte_data(client, n); |
| |
| if (ret < 0) { |
| dev_err(&client->dev, "%s: reg 0x%x, err %d\n", |
| __func__, n, ret); |
| return ret; |
| } |
| *val = (u8)ret; |
| return 0; |
| |
| } |
| |
| static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset) |
| { |
| struct pca955x *pca955x = gpiochip_get_data(gc); |
| struct pca955x_led *led = &pca955x->leds[offset]; |
| |
| if (led->type == PCA955X_TYPE_GPIO) |
| return 0; |
| |
| return -EBUSY; |
| } |
| |
| static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset, |
| int val) |
| { |
| struct pca955x *pca955x = gpiochip_get_data(gc); |
| struct pca955x_led *led = &pca955x->leds[offset]; |
| |
| if (val) |
| return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH); |
| |
| return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW); |
| } |
| |
| static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset, |
| int val) |
| { |
| pca955x_set_value(gc, offset, val); |
| } |
| |
| static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset) |
| { |
| struct pca955x *pca955x = gpiochip_get_data(gc); |
| struct pca955x_led *led = &pca955x->leds[offset]; |
| u8 reg = 0; |
| |
| /* There is nothing we can do about errors */ |
| pca955x_read_input(pca955x->client, led->led_num / 8, ®); |
| |
| return !!(reg & (1 << (led->led_num % 8))); |
| } |
| |
| static int pca955x_gpio_direction_input(struct gpio_chip *gc, |
| unsigned int offset) |
| { |
| struct pca955x *pca955x = gpiochip_get_data(gc); |
| struct pca955x_led *led = &pca955x->leds[offset]; |
| |
| /* To use as input ensure pin is not driven. */ |
| return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT); |
| } |
| |
| static int pca955x_gpio_direction_output(struct gpio_chip *gc, |
| unsigned int offset, int val) |
| { |
| return pca955x_set_value(gc, offset, val); |
| } |
| #endif /* CONFIG_LEDS_PCA955X_GPIO */ |
| |
| static struct pca955x_platform_data * |
| pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip) |
| { |
| struct pca955x_platform_data *pdata; |
| struct pca955x_led *led; |
| struct fwnode_handle *child; |
| int count; |
| |
| count = device_get_child_node_count(&client->dev); |
| if (!count || count > chip->bits) |
| return ERR_PTR(-ENODEV); |
| |
| pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL); |
| if (!pdata) |
| return ERR_PTR(-ENOMEM); |
| |
| pdata->leds = devm_kcalloc(&client->dev, |
| chip->bits, sizeof(struct pca955x_led), |
| GFP_KERNEL); |
| if (!pdata->leds) |
| return ERR_PTR(-ENOMEM); |
| |
| device_for_each_child_node(&client->dev, child) { |
| const char *state; |
| u32 reg; |
| int res; |
| |
| res = fwnode_property_read_u32(child, "reg", ®); |
| if ((res != 0) || (reg >= chip->bits)) |
| continue; |
| |
| led = &pdata->leds[reg]; |
| led->type = PCA955X_TYPE_LED; |
| led->fwnode = child; |
| fwnode_property_read_u32(child, "type", &led->type); |
| |
| if (!fwnode_property_read_string(child, "default-state", |
| &state)) { |
| if (!strcmp(state, "keep")) |
| led->default_state = LEDS_GPIO_DEFSTATE_KEEP; |
| else if (!strcmp(state, "on")) |
| led->default_state = LEDS_GPIO_DEFSTATE_ON; |
| else |
| led->default_state = LEDS_GPIO_DEFSTATE_OFF; |
| } else { |
| led->default_state = LEDS_GPIO_DEFSTATE_OFF; |
| } |
| } |
| |
| pdata->num_leds = chip->bits; |
| |
| return pdata; |
| } |
| |
| static const struct of_device_id of_pca955x_match[] = { |
| { .compatible = "nxp,pca9550", .data = (void *)pca9550 }, |
| { .compatible = "nxp,pca9551", .data = (void *)pca9551 }, |
| { .compatible = "nxp,pca9552", .data = (void *)pca9552 }, |
| { .compatible = "ibm,pca9552", .data = (void *)ibm_pca9552 }, |
| { .compatible = "nxp,pca9553", .data = (void *)pca9553 }, |
| {}, |
| }; |
| MODULE_DEVICE_TABLE(of, of_pca955x_match); |
| |
| static int pca955x_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| struct pca955x *pca955x; |
| struct pca955x_led *pca955x_led; |
| struct pca955x_chipdef *chip; |
| struct led_classdev *led; |
| struct led_init_data init_data; |
| struct i2c_adapter *adapter; |
| int i, err; |
| struct pca955x_platform_data *pdata; |
| int ngpios = 0; |
| bool set_default_label = false; |
| bool keep_pwm = false; |
| char default_label[8]; |
| |
| chip = &pca955x_chipdefs[id->driver_data]; |
| adapter = client->adapter; |
| pdata = dev_get_platdata(&client->dev); |
| if (!pdata) { |
| pdata = pca955x_get_pdata(client, chip); |
| if (IS_ERR(pdata)) |
| return PTR_ERR(pdata); |
| } |
| |
| /* Make sure the slave address / chip type combo given is possible */ |
| if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) != |
| chip->slv_addr) { |
| dev_err(&client->dev, "invalid slave address %02x\n", |
| client->addr); |
| return -ENODEV; |
| } |
| |
| dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at " |
| "slave address 0x%02x\n", client->name, chip->bits, |
| client->addr); |
| |
| if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) |
| return -EIO; |
| |
| if (pdata->num_leds != chip->bits) { |
| dev_err(&client->dev, |
| "board info claims %d LEDs on a %d-bit chip\n", |
| pdata->num_leds, chip->bits); |
| return -ENODEV; |
| } |
| |
| pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL); |
| if (!pca955x) |
| return -ENOMEM; |
| |
| pca955x->leds = devm_kcalloc(&client->dev, chip->bits, |
| sizeof(*pca955x_led), GFP_KERNEL); |
| if (!pca955x->leds) |
| return -ENOMEM; |
| |
| i2c_set_clientdata(client, pca955x); |
| |
| mutex_init(&pca955x->lock); |
| pca955x->client = client; |
| pca955x->chipdef = chip; |
| |
| init_data.devname_mandatory = false; |
| init_data.devicename = "pca955x"; |
| |
| for (i = 0; i < chip->bits; i++) { |
| pca955x_led = &pca955x->leds[i]; |
| pca955x_led->led_num = i; |
| pca955x_led->pca955x = pca955x; |
| pca955x_led->type = pdata->leds[i].type; |
| |
| switch (pca955x_led->type) { |
| case PCA955X_TYPE_NONE: |
| break; |
| case PCA955X_TYPE_GPIO: |
| ngpios++; |
| break; |
| case PCA955X_TYPE_LED: |
| led = &pca955x_led->led_cdev; |
| led->brightness_set_blocking = pca955x_led_set; |
| led->brightness_get = pca955x_led_get; |
| |
| if (pdata->leds[i].default_state == |
| LEDS_GPIO_DEFSTATE_OFF) { |
| err = pca955x_led_set(led, LED_OFF); |
| if (err) |
| return err; |
| } else if (pdata->leds[i].default_state == |
| LEDS_GPIO_DEFSTATE_ON) { |
| err = pca955x_led_set(led, LED_FULL); |
| if (err) |
| return err; |
| } |
| |
| init_data.fwnode = pdata->leds[i].fwnode; |
| |
| if (is_of_node(init_data.fwnode)) { |
| if (to_of_node(init_data.fwnode)->name[0] == |
| '\0') |
| set_default_label = true; |
| else |
| set_default_label = false; |
| } else { |
| set_default_label = true; |
| } |
| |
| if (set_default_label) { |
| snprintf(default_label, sizeof(default_label), |
| "%d", i); |
| init_data.default_label = default_label; |
| } else { |
| init_data.default_label = NULL; |
| } |
| |
| err = devm_led_classdev_register_ext(&client->dev, led, |
| &init_data); |
| if (err) |
| return err; |
| |
| /* |
| * For default-state == "keep", let the core update the |
| * brightness from the hardware, then check the |
| * brightness to see if it's using PWM1. If so, PWM1 |
| * should not be written below. |
| */ |
| if (pdata->leds[i].default_state == |
| LEDS_GPIO_DEFSTATE_KEEP) { |
| if (led->brightness != LED_FULL && |
| led->brightness != LED_OFF && |
| led->brightness != LED_HALF) |
| keep_pwm = true; |
| } |
| } |
| } |
| |
| /* PWM0 is used for half brightness or 50% duty cycle */ |
| err = pca955x_write_pwm(client, 0, 255 - LED_HALF); |
| if (err) |
| return err; |
| |
| if (!keep_pwm) { |
| /* PWM1 is used for variable brightness, default to OFF */ |
| err = pca955x_write_pwm(client, 1, 0); |
| if (err) |
| return err; |
| } |
| |
| /* Set to fast frequency so we do not see flashing */ |
| err = pca955x_write_psc(client, 0, 0); |
| if (err) |
| return err; |
| err = pca955x_write_psc(client, 1, 0); |
| if (err) |
| return err; |
| |
| #ifdef CONFIG_LEDS_PCA955X_GPIO |
| if (ngpios) { |
| pca955x->gpio.label = "gpio-pca955x"; |
| pca955x->gpio.direction_input = pca955x_gpio_direction_input; |
| pca955x->gpio.direction_output = pca955x_gpio_direction_output; |
| pca955x->gpio.set = pca955x_gpio_set_value; |
| pca955x->gpio.get = pca955x_gpio_get_value; |
| pca955x->gpio.request = pca955x_gpio_request_pin; |
| pca955x->gpio.can_sleep = 1; |
| pca955x->gpio.base = -1; |
| pca955x->gpio.ngpio = ngpios; |
| pca955x->gpio.parent = &client->dev; |
| pca955x->gpio.owner = THIS_MODULE; |
| |
| err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio, |
| pca955x); |
| if (err) { |
| /* Use data->gpio.dev as a flag for freeing gpiochip */ |
| pca955x->gpio.parent = NULL; |
| dev_warn(&client->dev, "could not add gpiochip\n"); |
| return err; |
| } |
| dev_info(&client->dev, "gpios %i...%i\n", |
| pca955x->gpio.base, pca955x->gpio.base + |
| pca955x->gpio.ngpio - 1); |
| } |
| #endif |
| |
| return 0; |
| } |
| |
| static struct i2c_driver pca955x_driver = { |
| .driver = { |
| .name = "leds-pca955x", |
| .of_match_table = of_pca955x_match, |
| }, |
| .probe = pca955x_probe, |
| .id_table = pca955x_id, |
| }; |
| |
| module_i2c_driver(pca955x_driver); |
| |
| MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>"); |
| MODULE_DESCRIPTION("PCA955x LED driver"); |
| MODULE_LICENSE("GPL v2"); |