--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Awinic AW20036/AW20054/AW20072 LED driver
+ *
+ * Copyright (c) 2023, SberDevices. All Rights Reserved.
+ *
+ * Author: Martin Kurbanov <mmkurbanov@sberdevices.ru>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/container_of.h>
+#include <linux/i2c.h>
+#include <linux/leds.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/time.h>
+#include <linux/units.h>
+
+#define AW200XX_DIM_MAX (BIT(6) - 1)
+#define AW200XX_FADE_MAX (BIT(8) - 1)
+#define AW200XX_IMAX_DEFAULT_uA 60000
+#define AW200XX_IMAX_MAX_uA 160000
+#define AW200XX_IMAX_MIN_uA 3300
+
+/* Page 0 */
+#define AW200XX_REG_PAGE0_BASE 0xc000
+
+/* Select page register */
+#define AW200XX_REG_PAGE 0xF0
+#define AW200XX_PAGE_MASK (GENMASK(7, 6) | GENMASK(2, 0))
+#define AW200XX_PAGE_SHIFT 0
+#define AW200XX_NUM_PAGES 6
+#define AW200XX_PAGE_SIZE 256
+#define AW200XX_REG(page, reg) \
+ (AW200XX_REG_PAGE0_BASE + (page) * AW200XX_PAGE_SIZE + (reg))
+#define AW200XX_REG_MAX \
+ AW200XX_REG(AW200XX_NUM_PAGES - 1, AW200XX_PAGE_SIZE - 1)
+#define AW200XX_PAGE0 0
+#define AW200XX_PAGE1 1
+#define AW200XX_PAGE2 2
+#define AW200XX_PAGE3 3
+#define AW200XX_PAGE4 4
+#define AW200XX_PAGE5 5
+
+/* Chip ID register */
+#define AW200XX_REG_IDR AW200XX_REG(AW200XX_PAGE0, 0x00)
+#define AW200XX_IDR_CHIPID 0x18
+
+/* Sleep mode register */
+#define AW200XX_REG_SLPCR AW200XX_REG(AW200XX_PAGE0, 0x01)
+#define AW200XX_SLPCR_ACTIVE 0x00
+
+/* Reset register */
+#define AW200XX_REG_RSTR AW200XX_REG(AW200XX_PAGE0, 0x02)
+#define AW200XX_RSTR_RESET 0x01
+
+/* Global current configuration register */
+#define AW200XX_REG_GCCR AW200XX_REG(AW200XX_PAGE0, 0x03)
+#define AW200XX_GCCR_IMAX_MASK GENMASK(7, 4)
+#define AW200XX_GCCR_IMAX(x) ((x) << 4)
+#define AW200XX_GCCR_ALLON BIT(3)
+
+/* Fast clear display control register */
+#define AW200XX_REG_FCD AW200XX_REG(AW200XX_PAGE0, 0x04)
+#define AW200XX_FCD_CLEAR 0x01
+
+/* Display size configuration */
+#define AW200XX_REG_DSIZE AW200XX_REG(AW200XX_PAGE0, 0x80)
+#define AW200XX_DSIZE_COLUMNS_MAX 12
+
+#define AW200XX_LED2REG(x, columns) \
+ ((x) + (((x) / (columns)) * (AW200XX_DSIZE_COLUMNS_MAX - (columns))))
+
+/*
+ * DIM current configuration register (page 4).
+ * The even address for current DIM configuration.
+ * The odd address for current FADE configuration
+ */
+#define AW200XX_REG_DIM(x, columns) \
+ AW200XX_REG(AW200XX_PAGE4, AW200XX_LED2REG(x, columns) * 2)
+#define AW200XX_REG_DIM2FADE(x) ((x) + 1)
+
+/*
+ * Duty ratio of display scan (see p.15 of datasheet for formula):
+ * duty = (592us / 600.5us) * (1 / (display_rows + 1))
+ *
+ * Multiply to 1000 (MILLI) to improve the accuracy of calculations.
+ */
+#define AW200XX_DUTY_RATIO(rows) \
+ (((592UL * USEC_PER_SEC) / 600500UL) * (MILLI / (rows)) / MILLI)
+
+struct aw200xx_chipdef {
+ u32 channels;
+ u32 display_size_rows_max;
+ u32 display_size_columns;
+};
+
+struct aw200xx_led {
+ struct led_classdev cdev;
+ struct aw200xx *chip;
+ int dim;
+ u32 num;
+};
+
+struct aw200xx {
+ const struct aw200xx_chipdef *cdef;
+ struct i2c_client *client;
+ struct regmap *regmap;
+ struct mutex mutex;
+ u32 num_leds;
+ u32 display_rows;
+ struct aw200xx_led leds[];
+};
+
+static ssize_t dim_show(struct device *dev, struct device_attribute *devattr,
+ char *buf)
+{
+ struct led_classdev *cdev = dev_get_drvdata(dev);
+ struct aw200xx_led *led = container_of(cdev, struct aw200xx_led, cdev);
+ int dim = led->dim;
+
+ if (dim < 0)
+ return sysfs_emit(buf, "auto\n");
+
+ return sysfs_emit(buf, "%d\n", dim);
+}
+
+static ssize_t dim_store(struct device *dev, struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct led_classdev *cdev = dev_get_drvdata(dev);
+ struct aw200xx_led *led = container_of(cdev, struct aw200xx_led, cdev);
+ struct aw200xx *chip = led->chip;
+ u32 columns = chip->cdef->display_size_columns;
+ int dim;
+ ssize_t ret;
+
+ if (sysfs_streq(buf, "auto")) {
+ dim = -1;
+ } else {
+ ret = kstrtoint(buf, 0, &dim);
+ if (ret)
+ return ret;
+
+ if (dim > AW200XX_DIM_MAX)
+ return -EINVAL;
+ }
+
+ mutex_lock(&chip->mutex);
+
+ if (dim >= 0) {
+ ret = regmap_write(chip->regmap,
+ AW200XX_REG_DIM(led->num, columns), dim);
+ if (ret)
+ goto out_unlock;
+ }
+
+ led->dim = dim;
+ ret = count;
+
+out_unlock:
+ mutex_unlock(&chip->mutex);
+ return ret;
+}
+static DEVICE_ATTR_RW(dim);
+
+static struct attribute *dim_attrs[] = {
+ &dev_attr_dim.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(dim);
+
+static int aw200xx_brightness_set(struct led_classdev *cdev,
+ enum led_brightness brightness)
+{
+ struct aw200xx_led *led = container_of(cdev, struct aw200xx_led, cdev);
+ struct aw200xx *chip = led->chip;
+ int dim;
+ u32 reg;
+ int ret;
+
+ mutex_lock(&chip->mutex);
+
+ reg = AW200XX_REG_DIM(led->num, chip->cdef->display_size_columns);
+
+ dim = led->dim;
+ if (dim < 0)
+ dim = max_t(int,
+ brightness / (AW200XX_FADE_MAX / AW200XX_DIM_MAX),
+ 1);
+
+ ret = regmap_write(chip->regmap, reg, dim);
+ if (ret)
+ goto out_unlock;
+
+ ret = regmap_write(chip->regmap,
+ AW200XX_REG_DIM2FADE(reg), brightness);
+
+out_unlock:
+ mutex_unlock(&chip->mutex);
+
+ return ret;
+}
+
+static u32 aw200xx_imax_from_global(const struct aw200xx *const chip,
+ u32 global_imax_uA)
+{
+ u64 led_imax_uA;
+
+ /*
+ * The output current of each LED (see p.14 of datasheet for formula):
+ * Iled = Imax * (dim / 63) * ((fade + 1) / 256) * duty
+ *
+ * The value of duty is determined by the following formula:
+ * duty = (592us / 600.5us) * (1 / (display_rows + 1))
+ *
+ * Calculated for the maximum values of fade and dim.
+ * We divide by 1000 because we earlier multiplied by 1000 to improve
+ * accuracy when calculating the duty.
+ */
+ led_imax_uA = global_imax_uA * AW200XX_DUTY_RATIO(chip->display_rows);
+ do_div(led_imax_uA, MILLI);
+
+ return led_imax_uA;
+}
+
+static u32 aw200xx_imax_to_global(const struct aw200xx *const chip,
+ u32 led_imax_uA)
+{
+ u32 duty = AW200XX_DUTY_RATIO(chip->display_rows);
+
+ /* The output current of each LED (see p.14 of datasheet for formula) */
+ return (led_imax_uA * 1000U) / duty;
+}
+
+#define AW200XX_IMAX_MULTIPLIER1 10000
+#define AW200XX_IMAX_MULTIPLIER2 3333
+#define AW200XX_IMAX_BASE_VAL1 0
+#define AW200XX_IMAX_BASE_VAL2 8
+
+/*
+ * The AW200XX has a 4-bit register (GCCR) to configure the global current,
+ * which ranges from 3.3mA to 160mA. The following table indicates the values
+ * of the global current, divided into two parts:
+ *
+ * +-----------+-----------------+-----------+-----------------+
+ * | reg value | global max (mA) | reg value | global max (mA) |
+ * +-----------+-----------------+-----------+-----------------+
+ * | 0 | 10 | 8 | 3.3 |
+ * | 1 | 20 | 9 | 6.7 |
+ * | 2 | 30 | 10 | 10 |
+ * | 3 | 40 | 11 | 13.3 |
+ * | 4 | 60 | 12 | 20 |
+ * | 5 | 80 | 13 | 26.7 |
+ * | 6 | 120 | 14 | 40 |
+ * | 7 | 160 | 15 | 53.3 |
+ * +-----------+-----------------+-----------+-----------------+
+ *
+ * The left part with a multiplier of 10, and the right part with a multiplier
+ * of 3.3.
+ * So we have two formulas to calculate the global current:
+ * for the left part of the table:
+ * imax = coefficient * 10
+ *
+ * for the right part of the table:
+ * imax = coefficient * 3.3
+ *
+ * The coefficient table consists of the following values:
+ * 1, 2, 3, 4, 6, 8, 12, 16.
+ */
+static int aw200xx_set_imax(const struct aw200xx *const chip,
+ u32 led_imax_uA)
+{
+ u32 g_imax_uA = aw200xx_imax_to_global(chip, led_imax_uA);
+ u32 coeff_table[] = {1, 2, 3, 4, 6, 8, 12, 16};
+ u32 gccr_imax = UINT_MAX;
+ u32 cur_imax = 0;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(coeff_table); i++) {
+ u32 imax;
+
+ /* select closest ones */
+ imax = coeff_table[i] * AW200XX_IMAX_MULTIPLIER1;
+ if (g_imax_uA >= imax && imax > cur_imax) {
+ cur_imax = imax;
+ gccr_imax = i + AW200XX_IMAX_BASE_VAL1;
+ }
+
+ imax = coeff_table[i] * AW200XX_IMAX_MULTIPLIER2;
+ imax = DIV_ROUND_CLOSEST(imax, 100) * 100;
+ if (g_imax_uA >= imax && imax > cur_imax) {
+ cur_imax = imax;
+ gccr_imax = i + AW200XX_IMAX_BASE_VAL2;
+ }
+ }
+
+ if (gccr_imax == UINT_MAX)
+ return -EINVAL;
+
+ return regmap_update_bits(chip->regmap, AW200XX_REG_GCCR,
+ AW200XX_GCCR_IMAX_MASK,
+ AW200XX_GCCR_IMAX(gccr_imax));
+}
+
+static int aw200xx_chip_reset(const struct aw200xx *const chip)
+{
+ int ret;
+
+ ret = regmap_write(chip->regmap, AW200XX_REG_RSTR, AW200XX_RSTR_RESET);
+ if (ret)
+ return ret;
+
+ regcache_mark_dirty(chip->regmap);
+ return regmap_write(chip->regmap, AW200XX_REG_FCD, AW200XX_FCD_CLEAR);
+}
+
+static int aw200xx_chip_init(const struct aw200xx *const chip)
+{
+ int ret;
+
+ ret = regmap_write(chip->regmap, AW200XX_REG_DSIZE,
+ chip->display_rows - 1);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(chip->regmap, AW200XX_REG_SLPCR,
+ AW200XX_SLPCR_ACTIVE);
+ if (ret)
+ return ret;
+
+ return regmap_update_bits(chip->regmap, AW200XX_REG_GCCR,
+ AW200XX_GCCR_ALLON, AW200XX_GCCR_ALLON);
+}
+
+static int aw200xx_chip_check(const struct aw200xx *const chip)
+{
+ struct device *dev = &chip->client->dev;
+ u32 chipid;
+ int ret;
+
+ ret = regmap_read(chip->regmap, AW200XX_REG_IDR, &chipid);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to read chip ID\n");
+
+ if (chipid != AW200XX_IDR_CHIPID)
+ return dev_err_probe(dev, -ENODEV,
+ "Chip reported wrong ID: %x\n", chipid);
+
+ return 0;
+}
+
+static int aw200xx_probe_fw(struct device *dev, struct aw200xx *chip)
+{
+ struct fwnode_handle *child;
+ u32 current_min, current_max, min_uA;
+ int ret;
+ int i;
+
+ ret = device_property_read_u32(dev, "awinic,display-rows",
+ &chip->display_rows);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to read 'display-rows' property\n");
+
+ if (!chip->display_rows ||
+ chip->display_rows > chip->cdef->display_size_rows_max) {
+ return dev_err_probe(dev, ret,
+ "Invalid leds display size %u\n",
+ chip->display_rows);
+ }
+
+ current_max = aw200xx_imax_from_global(chip, AW200XX_IMAX_MAX_uA);
+ current_min = aw200xx_imax_from_global(chip, AW200XX_IMAX_MIN_uA);
+ min_uA = UINT_MAX;
+ i = 0;
+
+ device_for_each_child_node(dev, child) {
+ struct led_init_data init_data = {};
+ struct aw200xx_led *led;
+ u32 source, imax;
+
+ ret = fwnode_property_read_u32(child, "reg", &source);
+ if (ret) {
+ dev_err(dev, "Missing reg property\n");
+ chip->num_leds--;
+ continue;
+ }
+
+ if (source >= chip->cdef->channels) {
+ dev_err(dev, "LED reg %u out of range (max %u)\n",
+ source, chip->cdef->channels);
+ chip->num_leds--;
+ continue;
+ }
+
+ ret = fwnode_property_read_u32(child, "led-max-microamp",
+ &imax);
+ if (ret) {
+ dev_info(&chip->client->dev,
+ "DT property led-max-microamp is missing\n");
+ } else if (imax < current_min || imax > current_max) {
+ dev_err(dev, "Invalid value %u for led-max-microamp\n",
+ imax);
+ chip->num_leds--;
+ continue;
+ } else {
+ min_uA = min(min_uA, imax);
+ }
+
+ led = &chip->leds[i];
+ led->dim = -1;
+ led->num = source;
+ led->chip = chip;
+ led->cdev.brightness_set_blocking = aw200xx_brightness_set;
+ led->cdev.groups = dim_groups;
+ init_data.fwnode = child;
+
+ ret = devm_led_classdev_register_ext(dev, &led->cdev,
+ &init_data);
+ if (ret) {
+ fwnode_handle_put(child);
+ break;
+ }
+
+ i++;
+ }
+
+ if (!chip->num_leds)
+ return -EINVAL;
+
+ if (min_uA == UINT_MAX) {
+ min_uA = aw200xx_imax_from_global(chip,
+ AW200XX_IMAX_DEFAULT_uA);
+ }
+
+ return aw200xx_set_imax(chip, min_uA);
+}
+
+static const struct regmap_range_cfg aw200xx_ranges[] = {
+ {
+ .name = "aw200xx",
+ .range_min = 0,
+ .range_max = AW200XX_REG_MAX,
+ .selector_reg = AW200XX_REG_PAGE,
+ .selector_mask = AW200XX_PAGE_MASK,
+ .selector_shift = AW200XX_PAGE_SHIFT,
+ .window_start = 0,
+ .window_len = AW200XX_PAGE_SIZE,
+ },
+};
+
+static const struct regmap_range aw200xx_writeonly_ranges[] = {
+ regmap_reg_range(AW200XX_REG(AW200XX_PAGE1, 0x00), AW200XX_REG_MAX),
+};
+
+static const struct regmap_access_table aw200xx_readable_table = {
+ .no_ranges = aw200xx_writeonly_ranges,
+ .n_no_ranges = ARRAY_SIZE(aw200xx_writeonly_ranges),
+};
+
+static const struct regmap_range aw200xx_readonly_ranges[] = {
+ regmap_reg_range(AW200XX_REG_IDR, AW200XX_REG_IDR),
+};
+
+static const struct regmap_access_table aw200xx_writeable_table = {
+ .no_ranges = aw200xx_readonly_ranges,
+ .n_no_ranges = ARRAY_SIZE(aw200xx_readonly_ranges),
+};
+
+static const struct regmap_config aw200xx_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = AW200XX_REG_MAX,
+ .ranges = aw200xx_ranges,
+ .num_ranges = ARRAY_SIZE(aw200xx_ranges),
+ .rd_table = &aw200xx_readable_table,
+ .wr_table = &aw200xx_writeable_table,
+ .cache_type = REGCACHE_RBTREE,
+};
+
+static int aw200xx_probe(struct i2c_client *client)
+{
+ const struct aw200xx_chipdef *cdef;
+ struct aw200xx *chip;
+ int count;
+ int ret;
+
+ cdef = device_get_match_data(&client->dev);
+ if (!cdef)
+ return -ENODEV;
+
+ count = device_get_child_node_count(&client->dev);
+ if (!count || count > cdef->channels)
+ return dev_err_probe(&client->dev, -EINVAL,
+ "Incorrect number of leds (%d)", count);
+
+ chip = devm_kzalloc(&client->dev, struct_size(chip, leds, count),
+ GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ chip->cdef = cdef;
+ chip->num_leds = count;
+ chip->client = client;
+ i2c_set_clientdata(client, chip);
+
+ chip->regmap = devm_regmap_init_i2c(client, &aw200xx_regmap_config);
+ if (IS_ERR(chip->regmap))
+ return PTR_ERR(chip->regmap);
+
+ ret = aw200xx_chip_check(chip);
+ if (ret)
+ return ret;
+
+ mutex_init(&chip->mutex);
+
+ /* Need a lock now since after call aw200xx_probe_fw, sysfs nodes created */
+ mutex_lock(&chip->mutex);
+
+ ret = aw200xx_chip_reset(chip);
+ if (ret)
+ goto out_unlock;
+
+ ret = aw200xx_probe_fw(&client->dev, chip);
+ if (ret)
+ goto out_unlock;
+
+ ret = aw200xx_chip_init(chip);
+
+out_unlock:
+ mutex_unlock(&chip->mutex);
+ return ret;
+}
+
+static void aw200xx_remove(struct i2c_client *client)
+{
+ struct aw200xx *chip = i2c_get_clientdata(client);
+
+ aw200xx_chip_reset(chip);
+ mutex_destroy(&chip->mutex);
+}
+
+static const struct aw200xx_chipdef aw20036_cdef = {
+ .channels = 36,
+ .display_size_rows_max = 3,
+ .display_size_columns = 12,
+};
+
+static const struct aw200xx_chipdef aw20054_cdef = {
+ .channels = 54,
+ .display_size_rows_max = 6,
+ .display_size_columns = 9,
+};
+
+static const struct aw200xx_chipdef aw20072_cdef = {
+ .channels = 72,
+ .display_size_rows_max = 6,
+ .display_size_columns = 12,
+};
+
+static const struct i2c_device_id aw200xx_id[] = {
+ { "aw20036" },
+ { "aw20054" },
+ { "aw20072" },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, aw200xx_id);
+
+static const struct of_device_id aw200xx_match_table[] = {
+ { .compatible = "awinic,aw20036", .data = &aw20036_cdef, },
+ { .compatible = "awinic,aw20054", .data = &aw20054_cdef, },
+ { .compatible = "awinic,aw20072", .data = &aw20072_cdef, },
+ {}
+};
+MODULE_DEVICE_TABLE(of, aw200xx_match_table);
+
+static struct i2c_driver aw200xx_driver = {
+ .driver = {
+ .name = "aw200xx",
+ .of_match_table = aw200xx_match_table,
+ },
+ .probe_new = aw200xx_probe,
+ .remove = aw200xx_remove,
+ .id_table = aw200xx_id,
+};
+module_i2c_driver(aw200xx_driver);
+
+MODULE_AUTHOR("Martin Kurbanov <mmkurbanov@sberdevices.ru>");
+MODULE_DESCRIPTION("AW200XX LED driver");
+MODULE_LICENSE("GPL");
projects / linux-2.6-block.git / commitdiff