/* * Copyright 2007-2008 Extreme Engineering Solutions, Inc. * * Author: Nate Case * * This file is subject to the terms and conditions of version 2 of * the GNU General Public License. See the file COPYING in the main * directory of this archive for more details. * * 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 #include #include #include #include #include #include #include #include #include #include #include #include /* 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 */ enum pca955x_type { pca9550, pca9551, 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, }, [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 }, { "pca9553", pca9553 }, { } }; MODULE_DEVICE_TABLE(i2c, pca955x_id); static const struct acpi_device_id pca955x_acpi_ids[] = { { "PCA9550", pca9550 }, { "PCA9551", pca9551 }, { "PCA9552", pca9552 }, { "PCA9553", pca9553 }, { } }; MODULE_DEVICE_TABLE(acpi, pca955x_acpi_ids); 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 */ char name[32]; u32 type; const char *default_trigger; }; 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 void pca955x_write_psc(struct i2c_client *client, int n, u8 val) { struct pca955x *pca955x = i2c_get_clientdata(client); i2c_smbus_write_byte_data(client, pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n, val); } /* * 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 void pca955x_write_pwm(struct i2c_client *client, int n, u8 val) { struct pca955x *pca955x = i2c_get_clientdata(client); i2c_smbus_write_byte_data(client, pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n, val); } /* * Write to LED selector register, which determines the source that * drives the LED output. */ static void pca955x_write_ls(struct i2c_client *client, int n, u8 val) { struct pca955x *pca955x = i2c_get_clientdata(client); i2c_smbus_write_byte_data(client, pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n, val); } /* * Read the LED selector register, which determines the source that * drives the LED output. */ static u8 pca955x_read_ls(struct i2c_client *client, int n) { struct pca955x *pca955x = i2c_get_clientdata(client); return (u8) i2c_smbus_read_byte_data(client, pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n); } 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) */ 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); ls = pca955x_read_ls(pca955x->client, chip_ls); 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. */ pca955x_write_pwm(pca955x->client, 1, 255 - value); ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1); break; } pca955x_write_ls(pca955x->client, chip_ls, ls); mutex_unlock(&pca955x->lock); return 0; } #ifdef CONFIG_LEDS_PCA955X_GPIO /* * Read the INPUT register, which contains the state of LEDs. */ static u8 pca955x_read_input(struct i2c_client *client, int n) { return (u8)i2c_smbus_read_byte_data(client, n); } 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 void pca955x_gpio_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) pca955x_led_set(&led->led_cdev, LED_FULL); else pca955x_led_set(&led->led_cdev, LED_OFF); } 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 = 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) { /* To use as input ensure pin is not driven */ pca955x_gpio_set_value(gc, offset, 0); return 0; } static int pca955x_gpio_direction_output(struct gpio_chip *gc, unsigned int offset, int val) { pca955x_gpio_set_value(gc, offset, val); return 0; } #endif /* CONFIG_LEDS_PCA955X_GPIO */ #if IS_ENABLED(CONFIG_OF) static struct pca955x_platform_data * pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip) { struct device_node *np = client->dev.of_node; struct device_node *child; struct pca955x_platform_data *pdata; int count; count = of_get_child_count(np); 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_kzalloc(&client->dev, sizeof(struct pca955x_led) * chip->bits, GFP_KERNEL); if (!pdata->leds) return ERR_PTR(-ENOMEM); for_each_child_of_node(np, child) { const char *name; u32 reg; int res; res = of_property_read_u32(child, "reg", ®); if ((res != 0) || (reg >= chip->bits)) continue; if (of_property_read_string(child, "label", &name)) name = child->name; snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name), "%s", name); pdata->leds[reg].type = PCA955X_TYPE_LED; of_property_read_u32(child, "type", &pdata->leds[reg].type); of_property_read_string(child, "linux,default-trigger", &pdata->leds[reg].default_trigger); } 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 = "nxp,pca9553", .data = (void *)pca9553 }, {}, }; MODULE_DEVICE_TABLE(of, of_pca955x_match); #else static struct pca955x_platform_data * pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip) { return ERR_PTR(-ENODEV); } #endif 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 i2c_adapter *adapter; int i, err; struct pca955x_platform_data *pdata; int ngpios = 0; if (id) { chip = &pca955x_chipdefs[id->driver_data]; } else { const struct acpi_device_id *acpi_id; acpi_id = acpi_match_device(pca955x_acpi_ids, &client->dev); if (!acpi_id) return -ENODEV; chip = &pca955x_chipdefs[acpi_id->driver_data]; } adapter = to_i2c_adapter(client->dev.parent); pdata = dev_get_platdata(&client->dev); if (!pdata) { pdata = pca955x_pdata_of_init(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_kzalloc(&client->dev, sizeof(*pca955x_led) * chip->bits, GFP_KERNEL); if (!pca955x->leds) return -ENOMEM; i2c_set_clientdata(client, pca955x); mutex_init(&pca955x->lock); pca955x->client = client; pca955x->chipdef = chip; 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: /* * Platform data can specify LED names and * default triggers */ if (pdata->leds[i].name) snprintf(pca955x_led->name, sizeof(pca955x_led->name), "pca955x:%s", pdata->leds[i].name); if (pdata->leds[i].default_trigger) pca955x_led->led_cdev.default_trigger = pdata->leds[i].default_trigger; pca955x_led->led_cdev.name = pca955x_led->name; pca955x_led->led_cdev.brightness_set_blocking = pca955x_led_set; err = devm_led_classdev_register(&client->dev, &pca955x_led->led_cdev); if (err) return err; /* Turn off LED */ pca955x_led_set(&pca955x_led->led_cdev, LED_OFF); } } /* PWM0 is used for half brightness or 50% duty cycle */ pca955x_write_pwm(client, 0, 255-LED_HALF); /* PWM1 is used for variable brightness, default to OFF */ pca955x_write_pwm(client, 1, 0); /* Set to fast frequency so we do not see flashing */ pca955x_write_psc(client, 0, 0); pca955x_write_psc(client, 1, 0); #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", .acpi_match_table = ACPI_PTR(pca955x_acpi_ids), .of_match_table = of_match_ptr(of_pca955x_match), }, .probe = pca955x_probe, .id_table = pca955x_id, }; module_i2c_driver(pca955x_driver); MODULE_AUTHOR("Nate Case "); MODULE_DESCRIPTION("PCA955x LED driver"); MODULE_LICENSE("GPL v2");