diff options
Diffstat (limited to 'drivers/leds/leds-pca963x.c')
-rw-r--r-- | drivers/leds/leds-pca963x.c | 442 |
1 files changed, 442 insertions, 0 deletions
diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c new file mode 100644 index 000000000..a7e052c1d --- /dev/null +++ b/drivers/leds/leds-pca963x.c @@ -0,0 +1,442 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2011 bct electronic GmbH + * Copyright 2013 Qtechnology/AS + * + * Author: Peter Meerwald <p.meerwald@bct-electronic.com> + * Author: Ricardo Ribalda <ribalda@kernel.org> + * + * Based on leds-pca955x.c + * + * LED driver for the PCA9633 I2C LED driver (7-bit slave address 0x62) + * LED driver for the PCA9634/5 I2C LED driver (7-bit slave address set by hw.) + * + * Note that hardware blinking violates the leds infrastructure driver + * interface since the hardware only supports blinking all LEDs with the + * same delay_on/delay_off rates. That is, only the LEDs that are set to + * blink will actually blink but all LEDs that are set to blink will blink + * in identical fashion. The delay_on/delay_off values of the last LED + * that is set to blink will be used for all of the blinking LEDs. + * Hardware blinking is disabled by default but can be enabled by setting + * the 'blink_type' member in the platform_data struct to 'PCA963X_HW_BLINK' + * or by adding the 'nxp,hw-blink' property to the DTS. + */ + +#include <linux/module.h> +#include <linux/delay.h> +#include <linux/string.h> +#include <linux/ctype.h> +#include <linux/leds.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/property.h> +#include <linux/slab.h> +#include <linux/of.h> + +/* LED select registers determine the source that drives LED outputs */ +#define PCA963X_LED_OFF 0x0 /* LED driver off */ +#define PCA963X_LED_ON 0x1 /* LED driver on */ +#define PCA963X_LED_PWM 0x2 /* Controlled through PWM */ +#define PCA963X_LED_GRP_PWM 0x3 /* Controlled through PWM/GRPPWM */ + +#define PCA963X_MODE2_OUTDRV 0x04 /* Open-drain or totem pole */ +#define PCA963X_MODE2_INVRT 0x10 /* Normal or inverted direction */ +#define PCA963X_MODE2_DMBLNK 0x20 /* Enable blinking */ + +#define PCA963X_MODE1 0x00 +#define PCA963X_MODE2 0x01 +#define PCA963X_PWM_BASE 0x02 + +enum pca963x_type { + pca9633, + pca9634, + pca9635, +}; + +struct pca963x_chipdef { + u8 grppwm; + u8 grpfreq; + u8 ledout_base; + int n_leds; + unsigned int scaling; +}; + +static struct pca963x_chipdef pca963x_chipdefs[] = { + [pca9633] = { + .grppwm = 0x6, + .grpfreq = 0x7, + .ledout_base = 0x8, + .n_leds = 4, + }, + [pca9634] = { + .grppwm = 0xa, + .grpfreq = 0xb, + .ledout_base = 0xc, + .n_leds = 8, + }, + [pca9635] = { + .grppwm = 0x12, + .grpfreq = 0x13, + .ledout_base = 0x14, + .n_leds = 16, + }, +}; + +/* Total blink period in milliseconds */ +#define PCA963X_BLINK_PERIOD_MIN 42 +#define PCA963X_BLINK_PERIOD_MAX 10667 + +static const struct i2c_device_id pca963x_id[] = { + { "pca9632", pca9633 }, + { "pca9633", pca9633 }, + { "pca9634", pca9634 }, + { "pca9635", pca9635 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, pca963x_id); + +struct pca963x; + +struct pca963x_led { + struct pca963x *chip; + struct led_classdev led_cdev; + int led_num; /* 0 .. 15 potentially */ + bool blinking; + u8 gdc; + u8 gfrq; +}; + +struct pca963x { + struct pca963x_chipdef *chipdef; + struct mutex mutex; + struct i2c_client *client; + unsigned long leds_on; + struct pca963x_led leds[]; +}; + +static int pca963x_brightness(struct pca963x_led *led, + enum led_brightness brightness) +{ + struct i2c_client *client = led->chip->client; + struct pca963x_chipdef *chipdef = led->chip->chipdef; + u8 ledout_addr, ledout, mask, val; + int shift; + int ret; + + ledout_addr = chipdef->ledout_base + (led->led_num / 4); + shift = 2 * (led->led_num % 4); + mask = 0x3 << shift; + ledout = i2c_smbus_read_byte_data(client, ledout_addr); + + switch (brightness) { + case LED_FULL: + if (led->blinking) { + val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift); + ret = i2c_smbus_write_byte_data(client, + PCA963X_PWM_BASE + + led->led_num, + LED_FULL); + } else { + val = (ledout & ~mask) | (PCA963X_LED_ON << shift); + } + ret = i2c_smbus_write_byte_data(client, ledout_addr, val); + break; + case LED_OFF: + val = ledout & ~mask; + ret = i2c_smbus_write_byte_data(client, ledout_addr, val); + led->blinking = false; + break; + default: + ret = i2c_smbus_write_byte_data(client, + PCA963X_PWM_BASE + + led->led_num, + brightness); + if (ret < 0) + return ret; + + if (led->blinking) + val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift); + else + val = (ledout & ~mask) | (PCA963X_LED_PWM << shift); + + ret = i2c_smbus_write_byte_data(client, ledout_addr, val); + break; + } + + return ret; +} + +static void pca963x_blink(struct pca963x_led *led) +{ + struct i2c_client *client = led->chip->client; + struct pca963x_chipdef *chipdef = led->chip->chipdef; + u8 ledout_addr, ledout, mask, val, mode2; + int shift; + + ledout_addr = chipdef->ledout_base + (led->led_num / 4); + shift = 2 * (led->led_num % 4); + mask = 0x3 << shift; + mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2); + + i2c_smbus_write_byte_data(client, chipdef->grppwm, led->gdc); + + i2c_smbus_write_byte_data(client, chipdef->grpfreq, led->gfrq); + + if (!(mode2 & PCA963X_MODE2_DMBLNK)) + i2c_smbus_write_byte_data(client, PCA963X_MODE2, + mode2 | PCA963X_MODE2_DMBLNK); + + mutex_lock(&led->chip->mutex); + + ledout = i2c_smbus_read_byte_data(client, ledout_addr); + if ((ledout & mask) != (PCA963X_LED_GRP_PWM << shift)) { + val = (ledout & ~mask) | (PCA963X_LED_GRP_PWM << shift); + i2c_smbus_write_byte_data(client, ledout_addr, val); + } + + mutex_unlock(&led->chip->mutex); + led->blinking = true; +} + +static int pca963x_power_state(struct pca963x_led *led) +{ + struct i2c_client *client = led->chip->client; + unsigned long *leds_on = &led->chip->leds_on; + unsigned long cached_leds = *leds_on; + + if (led->led_cdev.brightness) + set_bit(led->led_num, leds_on); + else + clear_bit(led->led_num, leds_on); + + if (!(*leds_on) != !cached_leds) + return i2c_smbus_write_byte_data(client, PCA963X_MODE1, + *leds_on ? 0 : BIT(4)); + + return 0; +} + +static int pca963x_led_set(struct led_classdev *led_cdev, + enum led_brightness value) +{ + struct pca963x_led *led; + int ret; + + led = container_of(led_cdev, struct pca963x_led, led_cdev); + + mutex_lock(&led->chip->mutex); + + ret = pca963x_brightness(led, value); + if (ret < 0) + goto unlock; + ret = pca963x_power_state(led); + +unlock: + mutex_unlock(&led->chip->mutex); + return ret; +} + +static unsigned int pca963x_period_scale(struct pca963x_led *led, + unsigned int val) +{ + unsigned int scaling = led->chip->chipdef->scaling; + + return scaling ? DIV_ROUND_CLOSEST(val * scaling, 1000) : val; +} + +static int pca963x_blink_set(struct led_classdev *led_cdev, + unsigned long *delay_on, unsigned long *delay_off) +{ + unsigned long time_on, time_off, period; + struct pca963x_led *led; + u8 gdc, gfrq; + + led = container_of(led_cdev, struct pca963x_led, led_cdev); + + time_on = *delay_on; + time_off = *delay_off; + + /* If both zero, pick reasonable defaults of 500ms each */ + if (!time_on && !time_off) { + time_on = 500; + time_off = 500; + } + + period = pca963x_period_scale(led, time_on + time_off); + + /* If period not supported by hardware, default to someting sane. */ + if ((period < PCA963X_BLINK_PERIOD_MIN) || + (period > PCA963X_BLINK_PERIOD_MAX)) { + time_on = 500; + time_off = 500; + period = pca963x_period_scale(led, 1000); + } + + /* + * From manual: duty cycle = (GDC / 256) -> + * (time_on / period) = (GDC / 256) -> + * GDC = ((time_on * 256) / period) + */ + gdc = (pca963x_period_scale(led, time_on) * 256) / period; + + /* + * From manual: period = ((GFRQ + 1) / 24) in seconds. + * So, period (in ms) = (((GFRQ + 1) / 24) * 1000) -> + * GFRQ = ((period * 24 / 1000) - 1) + */ + gfrq = (period * 24 / 1000) - 1; + + led->gdc = gdc; + led->gfrq = gfrq; + + pca963x_blink(led); + led->led_cdev.brightness = LED_FULL; + pca963x_led_set(led_cdev, LED_FULL); + + *delay_on = time_on; + *delay_off = time_off; + + return 0; +} + +static int pca963x_register_leds(struct i2c_client *client, + struct pca963x *chip) +{ + struct pca963x_chipdef *chipdef = chip->chipdef; + struct pca963x_led *led = chip->leds; + struct device *dev = &client->dev; + struct fwnode_handle *child; + bool hw_blink; + s32 mode2; + u32 reg; + int ret; + + if (device_property_read_u32(dev, "nxp,period-scale", + &chipdef->scaling)) + chipdef->scaling = 1000; + + hw_blink = device_property_read_bool(dev, "nxp,hw-blink"); + + mode2 = i2c_smbus_read_byte_data(client, PCA963X_MODE2); + if (mode2 < 0) + return mode2; + + /* default to open-drain unless totem pole (push-pull) is specified */ + if (device_property_read_bool(dev, "nxp,totem-pole")) + mode2 |= PCA963X_MODE2_OUTDRV; + else + mode2 &= ~PCA963X_MODE2_OUTDRV; + + /* default to non-inverted output, unless inverted is specified */ + if (device_property_read_bool(dev, "nxp,inverted-out")) + mode2 |= PCA963X_MODE2_INVRT; + else + mode2 &= ~PCA963X_MODE2_INVRT; + + ret = i2c_smbus_write_byte_data(client, PCA963X_MODE2, mode2); + if (ret < 0) + return ret; + + device_for_each_child_node(dev, child) { + struct led_init_data init_data = {}; + char default_label[32]; + + ret = fwnode_property_read_u32(child, "reg", ®); + if (ret || reg >= chipdef->n_leds) { + dev_err(dev, "Invalid 'reg' property for node %pfw\n", + child); + ret = -EINVAL; + goto err; + } + + led->led_num = reg; + led->chip = chip; + led->led_cdev.brightness_set_blocking = pca963x_led_set; + if (hw_blink) + led->led_cdev.blink_set = pca963x_blink_set; + led->blinking = false; + + init_data.fwnode = child; + /* for backwards compatibility */ + init_data.devicename = "pca963x"; + snprintf(default_label, sizeof(default_label), "%d:%.2x:%u", + client->adapter->nr, client->addr, reg); + init_data.default_label = default_label; + + ret = devm_led_classdev_register_ext(dev, &led->led_cdev, + &init_data); + if (ret) { + dev_err(dev, "Failed to register LED for node %pfw\n", + child); + goto err; + } + + ++led; + } + + return 0; +err: + fwnode_handle_put(child); + return ret; +} + +static const struct of_device_id of_pca963x_match[] = { + { .compatible = "nxp,pca9632", }, + { .compatible = "nxp,pca9633", }, + { .compatible = "nxp,pca9634", }, + { .compatible = "nxp,pca9635", }, + {}, +}; +MODULE_DEVICE_TABLE(of, of_pca963x_match); + +static int pca963x_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct pca963x_chipdef *chipdef; + struct pca963x *chip; + int i, count; + + chipdef = &pca963x_chipdefs[id->driver_data]; + + count = device_get_child_node_count(dev); + if (!count || count > chipdef->n_leds) { + dev_err(dev, "Node %pfw must define between 1 and %d LEDs\n", + dev_fwnode(dev), chipdef->n_leds); + return -EINVAL; + } + + chip = devm_kzalloc(dev, struct_size(chip, leds, count), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + i2c_set_clientdata(client, chip); + + mutex_init(&chip->mutex); + chip->chipdef = chipdef; + chip->client = client; + + /* Turn off LEDs by default*/ + for (i = 0; i < chipdef->n_leds / 4; i++) + i2c_smbus_write_byte_data(client, chipdef->ledout_base + i, 0x00); + + /* Disable LED all-call address, and power down initially */ + i2c_smbus_write_byte_data(client, PCA963X_MODE1, BIT(4)); + + return pca963x_register_leds(client, chip); +} + +static struct i2c_driver pca963x_driver = { + .driver = { + .name = "leds-pca963x", + .of_match_table = of_pca963x_match, + }, + .probe = pca963x_probe, + .id_table = pca963x_id, +}; + +module_i2c_driver(pca963x_driver); + +MODULE_AUTHOR("Peter Meerwald <p.meerwald@bct-electronic.com>"); +MODULE_DESCRIPTION("PCA963X LED driver"); +MODULE_LICENSE("GPL v2"); |