--- /dev/null
+/*
+ * 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");
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff