// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2007-2008 Extreme Engineering Solutions, Inc. * * Author: Nate Case * * 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 */ #define PCA955X_GPIO_INPUT LED_OFF #define PCA955X_GPIO_HIGH LED_OFF #define PCA955X_GPIO_LOW LED_FULL #define PCA955X_BLINK_DEFAULT_MS 1000 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 */ int blink_div; /* PSC divider */ }; static struct pca955x_chipdef pca955x_chipdefs[] = { [pca9550] = { .bits = 2, .slv_addr = /* 110000x */ 0x60, .slv_addr_shift = 1, .blink_div = 44, }, [pca9551] = { .bits = 8, .slv_addr = /* 1100xxx */ 0x60, .slv_addr_shift = 3, .blink_div = 38, }, [pca9552] = { .bits = 16, .slv_addr = /* 1100xxx */ 0x60, .slv_addr_shift = 3, .blink_div = 44, }, [ibm_pca9552] = { .bits = 16, .slv_addr = /* 0110xxx */ 0x30, .slv_addr_shift = 3, .blink_div = 44, }, [pca9553] = { .bits = 4, .slv_addr = /* 110001x */ 0x62, .slv_addr_shift = 1, .blink_div = 44, }, }; 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_blink; unsigned long active_pins; unsigned long blink_period; #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; }; #define led_to_pca955x(l) container_of(l, struct pca955x_led, led_cdev) struct pca955x_platform_data { struct pca955x_led *leds; int num_leds; }; /* 8 bits per input register */ static inline int pca955x_num_input_regs(int bits) { return (bits + 7) / 8; } /* 4 bits per LED selector register */ static inline int pca955x_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)); } static inline int pca955x_ledstate(u8 ls, int led_num) { return (ls >> (led_num << 1)) & 0x3; } /* * Write to frequency prescaler register, used to program the * period of the PWM output. period = (PSCx + 1) / coeff * Where for pca9551 chips coeff = 38 and for all other chips coeff = 44 */ static int pca955x_write_psc(struct pca955x *pca955x, int n, u8 val) { u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + (2 * n); int ret; ret = i2c_smbus_write_byte_data(pca955x->client, cmd, val); if (ret < 0) dev_err(&pca955x->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 pca955x *pca955x, int n, u8 val) { u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n); int ret; ret = i2c_smbus_write_byte_data(pca955x->client, cmd, val); if (ret < 0) dev_err(&pca955x->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 pca955x *pca955x, int n, u8 val) { u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + 4 + n; int ret; ret = i2c_smbus_write_byte_data(pca955x->client, cmd, val); if (ret < 0) dev_err(&pca955x->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 pca955x *pca955x, int n, u8 *val) { u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + 4 + n; int ret; ret = i2c_smbus_read_byte_data(pca955x->client, cmd); if (ret < 0) { dev_err(&pca955x->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 pca955x *pca955x, int n, u8 *val) { u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n); int ret; ret = i2c_smbus_read_byte_data(pca955x->client, cmd); if (ret < 0) { dev_err(&pca955x->client->dev, "%s: reg 0x%x, err %d\n", __func__, n, ret); return ret; } *val = (u8)ret; return 0; } static int pca955x_read_psc(struct pca955x *pca955x, int n, u8 *val) { u8 cmd = pca955x_num_input_regs(pca955x->chipdef->bits) + (2 * n); int ret; ret = i2c_smbus_read_byte_data(pca955x->client, cmd); if (ret < 0) { dev_err(&pca955x->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 = led_to_pca955x(led_cdev); struct pca955x *pca955x = pca955x_led->pca955x; u8 ls, pwm; int ret; ret = pca955x_read_ls(pca955x, pca955x_led->led_num / 4, &ls); if (ret) return ret; switch (pca955x_ledstate(ls, pca955x_led->led_num % 4)) { case PCA955X_LS_LED_ON: ret = LED_FULL; break; case PCA955X_LS_LED_OFF: ret = LED_OFF; break; case PCA955X_LS_BLINK0: ret = pca955x_read_pwm(pca955x, 0, &pwm); if (ret) return ret; ret = 256 - pwm; break; case PCA955X_LS_BLINK1: ret = pca955x_read_pwm(pca955x, 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 = led_to_pca955x(led_cdev); struct pca955x *pca955x = pca955x_led->pca955x; int reg = pca955x_led->led_num / 4; int bit = pca955x_led->led_num % 4; u8 ls; int ret; mutex_lock(&pca955x->lock); ret = pca955x_read_ls(pca955x, reg, &ls); if (ret) goto out; if (test_bit(pca955x_led->led_num, &pca955x->active_blink)) { if (value == LED_OFF) { clear_bit(pca955x_led->led_num, &pca955x->active_blink); ls = pca955x_ledsel(ls, bit, PCA955X_LS_LED_OFF); } else { ret = pca955x_write_pwm(pca955x, 0, 256 - value); goto out; } } else { switch (value) { case LED_FULL: ls = pca955x_ledsel(ls, bit, PCA955X_LS_LED_ON); break; case LED_OFF: ls = pca955x_ledsel(ls, bit, PCA955X_LS_LED_OFF); 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 or FULL. But, this is probably better than just * turning off for all other values. */ ret = pca955x_write_pwm(pca955x, 1, 255 - value); if (ret) goto out; ls = pca955x_ledsel(ls, bit, PCA955X_LS_BLINK1); break; } } ret = pca955x_write_ls(pca955x, reg, ls); out: mutex_unlock(&pca955x->lock); return ret; } static u8 pca955x_period_to_psc(struct pca955x *pca955x, unsigned long p) { p *= pca955x->chipdef->blink_div; p /= MSEC_PER_SEC; p -= 1; return p; } static unsigned long pca955x_psc_to_period(struct pca955x *pca955x, u8 psc) { unsigned long p = psc; p += 1; p *= MSEC_PER_SEC; p /= pca955x->chipdef->blink_div; return p; } static int pca955x_led_blink(struct led_classdev *led_cdev, unsigned long *delay_on, unsigned long *delay_off) { struct pca955x_led *pca955x_led = led_to_pca955x(led_cdev); struct pca955x *pca955x = pca955x_led->pca955x; unsigned long p = *delay_on + *delay_off; int ret = 0; mutex_lock(&pca955x->lock); if (p) { if (*delay_on != *delay_off) { ret = -EINVAL; goto out; } if (p < pca955x_psc_to_period(pca955x, 0) || p > pca955x_psc_to_period(pca955x, 0xff)) { ret = -EINVAL; goto out; } } else { p = pca955x->active_blink ? pca955x->blink_period : PCA955X_BLINK_DEFAULT_MS; } if (!pca955x->active_blink || pca955x->active_blink == BIT(pca955x_led->led_num) || pca955x->blink_period == p) { u8 psc = pca955x_period_to_psc(pca955x, p); if (!test_and_set_bit(pca955x_led->led_num, &pca955x->active_blink)) { u8 ls; int reg = pca955x_led->led_num / 4; int bit = pca955x_led->led_num % 4; ret = pca955x_read_ls(pca955x, reg, &ls); if (ret) goto out; ls = pca955x_ledsel(ls, bit, PCA955X_LS_BLINK0); ret = pca955x_write_ls(pca955x, reg, ls); if (ret) goto out; } if (pca955x->blink_period != p) { pca955x->blink_period = p; ret = pca955x_write_psc(pca955x, 0, psc); if (ret) goto out; } p = pca955x_psc_to_period(pca955x, psc); p /= 2; *delay_on = p; *delay_off = p; } else { ret = -EBUSY; } 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, bit, err, nls, reg; u8 ls1[4]; u8 ls2[4]; struct pca955x_platform_data *pdata; u8 psc0; bool keep_psc0 = false; bool set_default_label = 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; pca955x->blink_period = PCA955X_BLINK_DEFAULT_MS; init_data.devname_mandatory = false; init_data.devicename = "pca955x"; nls = pca955x_num_led_regs(chip->bits); for (i = 0; i < nls; ++i) { err = pca955x_read_ls(pca955x, i, &ls1[i]); if (err) return err; ls2[i] = ls1[i]; } 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: bit = i % 4; reg = i / 4; led = &pca955x_led->led_cdev; led->brightness_set_blocking = pca955x_led_set; led->brightness_get = pca955x_led_get; led->blink_set = pca955x_led_blink; if (pdata->leds[i].default_state == LEDS_GPIO_DEFSTATE_OFF) { ls2[reg] = pca955x_ledsel(ls2[reg], bit, PCA955X_LS_LED_OFF); } else if (pdata->leds[i].default_state == LEDS_GPIO_DEFSTATE_ON) { ls2[reg] = pca955x_ledsel(ls2[reg], bit, PCA955X_LS_LED_ON); } else if (pca955x_ledstate(ls2[reg], bit) == PCA955X_LS_BLINK0) { keep_psc0 = true; set_bit(i, &pca955x->active_blink); } 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 (i = 0; i < nls; ++i) { if (ls1[i] != ls2[i]) { err = pca955x_write_ls(pca955x, i, ls2[i]); if (err) return err; } } if (keep_psc0) { err = pca955x_read_psc(pca955x, 0, &psc0); } else { psc0 = pca955x_period_to_psc(pca955x, pca955x->blink_period); err = pca955x_write_psc(pca955x, 0, psc0); } if (err) return err; pca955x->blink_period = pca955x_psc_to_period(pca955x, psc0); /* Set PWM1 to fast frequency so we do not see flashing */ err = pca955x_write_psc(pca955x, 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 "); MODULE_DESCRIPTION("PCA955x LED driver"); MODULE_LICENSE("GPL v2");