diff options
Diffstat (limited to 'drivers/leds/leds-pca955x.c')
| -rw-r--r-- | drivers/leds/leds-pca955x.c | 699 |
1 files changed, 699 insertions, 0 deletions
diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c new file mode 100644 index 000000000..81aaf2121 --- /dev/null +++ b/drivers/leds/leds-pca955x.c @@ -0,0 +1,699 @@ +// 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/bitops.h> +#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; + unsigned long active_pins; +#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); + + return test_and_set_bit(offset, &pca955x->active_pins) ? -EBUSY : 0; +} + +static void pca955x_gpio_free_pin(struct gpio_chip *gc, unsigned int offset) +{ + struct pca955x *pca955x = gpiochip_get_data(gc); + + clear_bit(offset, &pca955x->active_pins); +} + +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 > 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) +{ + 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; + bool set_default_label = false; + bool keep_pwm = false; + char default_label[8]; + enum pca955x_type chip_type; + const void *md = device_get_match_data(&client->dev); + + if (md) { + chip_type = (enum pca955x_type)md; + } else { + const struct i2c_device_id *id = i2c_match_id(pca955x_id, + client); + + if (id) { + chip_type = (enum pca955x_type)id->driver_data; + } else { + dev_err(&client->dev, "unknown chip\n"); + return -ENODEV; + } + } + + chip = &pca955x_chipdefs[chip_type]; + 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: + case PCA955X_TYPE_GPIO: + 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; + + set_bit(i, &pca955x->active_pins); + + /* + * 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 + 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.free = pca955x_gpio_free_pin; + pca955x->gpio.can_sleep = 1; + pca955x->gpio.base = -1; + pca955x->gpio.ngpio = chip->bits; + 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_new = 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"); |