/* * Copyright 2015-16 Golden Delicious Computers * * Author: Nikolaus Schaller <hns@goldelico.com> * * 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 the IS31FL319{0,1,3,6,9} to drive 1, 3, 6 or 9 light * effect LEDs. * */ #include <linux/err.h> #include <linux/i2c.h> #include <linux/leds.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/regmap.h> #include <linux/slab.h> /* register numbers */ #define IS31FL319X_SHUTDOWN 0x00 #define IS31FL319X_CTRL1 0x01 #define IS31FL319X_CTRL2 0x02 #define IS31FL319X_CONFIG1 0x03 #define IS31FL319X_CONFIG2 0x04 #define IS31FL319X_RAMP_MODE 0x05 #define IS31FL319X_BREATH_MASK 0x06 #define IS31FL319X_PWM(channel) (0x07 + channel) #define IS31FL319X_DATA_UPDATE 0x10 #define IS31FL319X_T0(channel) (0x11 + channel) #define IS31FL319X_T123_1 0x1a #define IS31FL319X_T123_2 0x1b #define IS31FL319X_T123_3 0x1c #define IS31FL319X_T4(channel) (0x1d + channel) #define IS31FL319X_TIME_UPDATE 0x26 #define IS31FL319X_RESET 0xff #define IS31FL319X_REG_CNT (IS31FL319X_RESET + 1) #define IS31FL319X_MAX_LEDS 9 /* CS (Current Setting) in CONFIG2 register */ #define IS31FL319X_CONFIG2_CS_SHIFT 4 #define IS31FL319X_CONFIG2_CS_MASK 0x7 #define IS31FL319X_CONFIG2_CS_STEP_REF 12 #define IS31FL319X_CURRENT_MIN ((u32)5000) #define IS31FL319X_CURRENT_MAX ((u32)40000) #define IS31FL319X_CURRENT_STEP ((u32)5000) #define IS31FL319X_CURRENT_DEFAULT ((u32)20000) /* Audio gain in CONFIG2 register */ #define IS31FL319X_AUDIO_GAIN_DB_MAX ((u32)21) #define IS31FL319X_AUDIO_GAIN_DB_STEP ((u32)3) /* * regmap is used as a cache of chip's register space, * to avoid reading back brightness values from chip, * which is known to hang. */ struct is31fl319x_chip { const struct is31fl319x_chipdef *cdef; struct i2c_client *client; struct regmap *regmap; struct mutex lock; u32 audio_gain_db; struct is31fl319x_led { struct is31fl319x_chip *chip; struct led_classdev cdev; u32 max_microamp; bool configured; } leds[IS31FL319X_MAX_LEDS]; }; struct is31fl319x_chipdef { int num_leds; }; static const struct is31fl319x_chipdef is31fl3190_cdef = { .num_leds = 1, }; static const struct is31fl319x_chipdef is31fl3193_cdef = { .num_leds = 3, }; static const struct is31fl319x_chipdef is31fl3196_cdef = { .num_leds = 6, }; static const struct is31fl319x_chipdef is31fl3199_cdef = { .num_leds = 9, }; static const struct of_device_id of_is31fl319x_match[] = { { .compatible = "issi,is31fl3190", .data = &is31fl3190_cdef, }, { .compatible = "issi,is31fl3191", .data = &is31fl3190_cdef, }, { .compatible = "issi,is31fl3193", .data = &is31fl3193_cdef, }, { .compatible = "issi,is31fl3196", .data = &is31fl3196_cdef, }, { .compatible = "issi,is31fl3199", .data = &is31fl3199_cdef, }, { .compatible = "si-en,sn3199", .data = &is31fl3199_cdef, }, { } }; MODULE_DEVICE_TABLE(of, of_is31fl319x_match); static int is31fl319x_brightness_set(struct led_classdev *cdev, enum led_brightness brightness) { struct is31fl319x_led *led = container_of(cdev, struct is31fl319x_led, cdev); struct is31fl319x_chip *is31 = led->chip; int chan = led - is31->leds; int ret; int i; u8 ctrl1 = 0, ctrl2 = 0; dev_dbg(&is31->client->dev, "%s %d: %d\n", __func__, chan, brightness); mutex_lock(&is31->lock); /* update PWM register */ ret = regmap_write(is31->regmap, IS31FL319X_PWM(chan), brightness); if (ret < 0) goto out; /* read current brightness of all PWM channels */ for (i = 0; i < is31->cdef->num_leds; i++) { unsigned int pwm_value; bool on; /* * since neither cdev nor the chip can provide * the current setting, we read from the regmap cache */ ret = regmap_read(is31->regmap, IS31FL319X_PWM(i), &pwm_value); dev_dbg(&is31->client->dev, "%s read %d: ret=%d: %d\n", __func__, i, ret, pwm_value); on = ret >= 0 && pwm_value > LED_OFF; if (i < 3) ctrl1 |= on << i; /* 0..2 => bit 0..2 */ else if (i < 6) ctrl1 |= on << (i + 1); /* 3..5 => bit 4..6 */ else ctrl2 |= on << (i - 6); /* 6..8 => bit 0..2 */ } if (ctrl1 > 0 || ctrl2 > 0) { dev_dbg(&is31->client->dev, "power up %02x %02x\n", ctrl1, ctrl2); regmap_write(is31->regmap, IS31FL319X_CTRL1, ctrl1); regmap_write(is31->regmap, IS31FL319X_CTRL2, ctrl2); /* update PWMs */ regmap_write(is31->regmap, IS31FL319X_DATA_UPDATE, 0x00); /* enable chip from shut down */ ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x01); } else { dev_dbg(&is31->client->dev, "power down\n"); /* shut down (no need to clear CTRL1/2) */ ret = regmap_write(is31->regmap, IS31FL319X_SHUTDOWN, 0x00); } out: mutex_unlock(&is31->lock); return ret; } static int is31fl319x_parse_child_dt(const struct device *dev, const struct device_node *child, struct is31fl319x_led *led) { struct led_classdev *cdev = &led->cdev; int ret; if (of_property_read_string(child, "label", &cdev->name)) cdev->name = child->name; ret = of_property_read_string(child, "linux,default-trigger", &cdev->default_trigger); if (ret < 0 && ret != -EINVAL) /* is optional */ return ret; led->max_microamp = IS31FL319X_CURRENT_DEFAULT; ret = of_property_read_u32(child, "led-max-microamp", &led->max_microamp); if (!ret) { if (led->max_microamp < IS31FL319X_CURRENT_MIN) return -EINVAL; /* not supported */ led->max_microamp = min(led->max_microamp, IS31FL319X_CURRENT_MAX); } return 0; } static int is31fl319x_parse_dt(struct device *dev, struct is31fl319x_chip *is31) { struct device_node *np = dev->of_node, *child; const struct of_device_id *of_dev_id; int count; int ret; if (!np) return -ENODEV; of_dev_id = of_match_device(of_is31fl319x_match, dev); if (!of_dev_id) { dev_err(dev, "Failed to match device with supported chips\n"); return -EINVAL; } is31->cdef = of_dev_id->data; count = of_get_child_count(np); dev_dbg(dev, "probe %s with %d leds defined in DT\n", of_dev_id->compatible, count); if (!count || count > is31->cdef->num_leds) { dev_err(dev, "Number of leds defined must be between 1 and %u\n", is31->cdef->num_leds); return -ENODEV; } for_each_child_of_node(np, child) { struct is31fl319x_led *led; u32 reg; ret = of_property_read_u32(child, "reg", ®); if (ret) { dev_err(dev, "Failed to read led 'reg' property\n"); goto put_child_node; } if (reg < 1 || reg > is31->cdef->num_leds) { dev_err(dev, "invalid led reg %u\n", reg); ret = -EINVAL; goto put_child_node; } led = &is31->leds[reg - 1]; if (led->configured) { dev_err(dev, "led %u is already configured\n", reg); ret = -EINVAL; goto put_child_node; } ret = is31fl319x_parse_child_dt(dev, child, led); if (ret) { dev_err(dev, "led %u DT parsing failed\n", reg); goto put_child_node; } led->configured = true; } is31->audio_gain_db = 0; ret = of_property_read_u32(np, "audio-gain-db", &is31->audio_gain_db); if (!ret) is31->audio_gain_db = min(is31->audio_gain_db, IS31FL319X_AUDIO_GAIN_DB_MAX); return 0; put_child_node: of_node_put(child); return ret; } static bool is31fl319x_readable_reg(struct device *dev, unsigned int reg) { /* we have no readable registers */ return false; } static bool is31fl319x_volatile_reg(struct device *dev, unsigned int reg) { /* volatile registers are not cached */ switch (reg) { case IS31FL319X_DATA_UPDATE: case IS31FL319X_TIME_UPDATE: case IS31FL319X_RESET: return true; /* always write-through */ default: return false; } } static const struct reg_default is31fl319x_reg_defaults[] = { { IS31FL319X_CONFIG1, 0x00}, { IS31FL319X_CONFIG2, 0x00}, { IS31FL319X_PWM(0), 0x00}, { IS31FL319X_PWM(1), 0x00}, { IS31FL319X_PWM(2), 0x00}, { IS31FL319X_PWM(3), 0x00}, { IS31FL319X_PWM(4), 0x00}, { IS31FL319X_PWM(5), 0x00}, { IS31FL319X_PWM(6), 0x00}, { IS31FL319X_PWM(7), 0x00}, { IS31FL319X_PWM(8), 0x00}, }; static struct regmap_config regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = IS31FL319X_REG_CNT, .cache_type = REGCACHE_FLAT, .readable_reg = is31fl319x_readable_reg, .volatile_reg = is31fl319x_volatile_reg, .reg_defaults = is31fl319x_reg_defaults, .num_reg_defaults = ARRAY_SIZE(is31fl319x_reg_defaults), }; static inline int is31fl319x_microamp_to_cs(struct device *dev, u32 microamp) { /* round down to nearest supported value (range check done by caller) */ u32 step = microamp / IS31FL319X_CURRENT_STEP; return ((IS31FL319X_CONFIG2_CS_STEP_REF - step) & IS31FL319X_CONFIG2_CS_MASK) << IS31FL319X_CONFIG2_CS_SHIFT; /* CS encoding */ } static inline int is31fl319x_db_to_gain(u32 dezibel) { /* round down to nearest supported value (range check done by caller) */ return dezibel / IS31FL319X_AUDIO_GAIN_DB_STEP; } static int is31fl319x_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct is31fl319x_chip *is31; struct device *dev = &client->dev; struct i2c_adapter *adapter = to_i2c_adapter(dev->parent); int err; int i = 0; u32 aggregated_led_microamp = IS31FL319X_CURRENT_MAX; if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) return -EIO; is31 = devm_kzalloc(&client->dev, sizeof(*is31), GFP_KERNEL); if (!is31) return -ENOMEM; mutex_init(&is31->lock); err = is31fl319x_parse_dt(&client->dev, is31); if (err) goto free_mutex; is31->client = client; is31->regmap = devm_regmap_init_i2c(client, ®map_config); if (IS_ERR(is31->regmap)) { dev_err(&client->dev, "failed to allocate register map\n"); err = PTR_ERR(is31->regmap); goto free_mutex; } i2c_set_clientdata(client, is31); /* check for write-reply from chip (we can't read any registers) */ err = regmap_write(is31->regmap, IS31FL319X_RESET, 0x00); if (err < 0) { dev_err(&client->dev, "no response from chip write: err = %d\n", err); err = -EIO; /* does not answer */ goto free_mutex; } /* * Kernel conventions require per-LED led-max-microamp property. * But the chip does not allow to limit individual LEDs. * So we take minimum from all subnodes for safety of hardware. */ for (i = 0; i < is31->cdef->num_leds; i++) if (is31->leds[i].configured && is31->leds[i].max_microamp < aggregated_led_microamp) aggregated_led_microamp = is31->leds[i].max_microamp; regmap_write(is31->regmap, IS31FL319X_CONFIG2, is31fl319x_microamp_to_cs(dev, aggregated_led_microamp) | is31fl319x_db_to_gain(is31->audio_gain_db)); for (i = 0; i < is31->cdef->num_leds; i++) { struct is31fl319x_led *led = &is31->leds[i]; if (!led->configured) continue; led->chip = is31; led->cdev.brightness_set_blocking = is31fl319x_brightness_set; err = devm_led_classdev_register(&client->dev, &led->cdev); if (err < 0) goto free_mutex; } return 0; free_mutex: mutex_destroy(&is31->lock); return err; } static int is31fl319x_remove(struct i2c_client *client) { struct is31fl319x_chip *is31 = i2c_get_clientdata(client); mutex_destroy(&is31->lock); return 0; } /* * i2c-core (and modalias) requires that id_table be properly filled, * even though it is not used for DeviceTree based instantiation. */ static const struct i2c_device_id is31fl319x_id[] = { { "is31fl3190" }, { "is31fl3191" }, { "is31fl3193" }, { "is31fl3196" }, { "is31fl3199" }, { "sn3199" }, {}, }; MODULE_DEVICE_TABLE(i2c, is31fl319x_id); static struct i2c_driver is31fl319x_driver = { .driver = { .name = "leds-is31fl319x", .of_match_table = of_match_ptr(of_is31fl319x_match), }, .probe = is31fl319x_probe, .remove = is31fl319x_remove, .id_table = is31fl319x_id, }; module_i2c_driver(is31fl319x_driver); MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>"); MODULE_AUTHOR("Andrey Utkin <andrey_utkin@fastmail.com>"); MODULE_DESCRIPTION("IS31FL319X LED driver"); MODULE_LICENSE("GPL v2");