--- /dev/null
+/*
+ * Driver for ISSI IS31FL32xx family of I2C LED controllers
+ *
+ * Copyright 2015 Allworx Corp.
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Datasheets: http://www.issi.com/US/product-analog-fxled-driver.shtml
+ */
+
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+/* Used to indicate a device has no such register */
+#define IS31FL32XX_REG_NONE 0xFF
+
+/* Software Shutdown bit in Shutdown Register */
+#define IS31FL32XX_SHUTDOWN_SSD_ENABLE 0
+#define IS31FL32XX_SHUTDOWN_SSD_DISABLE BIT(0)
+
+/* IS31FL3216 has a number of unique registers */
+#define IS31FL3216_CONFIG_REG 0x00
+#define IS31FL3216_LIGHTING_EFFECT_REG 0x03
+#define IS31FL3216_CHANNEL_CONFIG_REG 0x04
+
+/* Software Shutdown bit in 3216 Config Register */
+#define IS31FL3216_CONFIG_SSD_ENABLE BIT(7)
+#define IS31FL3216_CONFIG_SSD_DISABLE 0
+
+struct is31fl32xx_priv;
+struct is31fl32xx_led_data {
+ struct led_classdev cdev;
+ u8 channel; /* 1-based, max priv->cdef->channels */
+ struct is31fl32xx_priv *priv;
+};
+
+struct is31fl32xx_priv {
+ const struct is31fl32xx_chipdef *cdef;
+ struct i2c_client *client;
+ unsigned int num_leds;
+ struct is31fl32xx_led_data leds[0];
+};
+
+/**
+ * struct is31fl32xx_chipdef - chip-specific attributes
+ * @channels : Number of LED channels
+ * @shutdown_reg : address of Shutdown register (optional)
+ * @pwm_update_reg : address of PWM Update register
+ * @global_control_reg : address of Global Control register (optional)
+ * @reset_reg : address of Reset register (optional)
+ * @pwm_register_base : address of first PWM register
+ * @pwm_registers_reversed: : true if PWM registers count down instead of up
+ * @led_control_register_base : address of first LED control register (optional)
+ * @enable_bits_per_led_control_register: number of LEDs enable bits in each
+ * @reset_func: : pointer to reset function
+ *
+ * For all optional register addresses, the sentinel value %IS31FL32XX_REG_NONE
+ * indicates that this chip has no such register.
+ *
+ * If non-NULL, @reset_func will be called during probing to set all
+ * necessary registers to a known initialization state. This is needed
+ * for chips that do not have a @reset_reg.
+ *
+ * @enable_bits_per_led_control_register must be >=1 if
+ * @led_control_register_base != %IS31FL32XX_REG_NONE.
+ */
+struct is31fl32xx_chipdef {
+ u8 channels;
+ u8 shutdown_reg;
+ u8 pwm_update_reg;
+ u8 global_control_reg;
+ u8 reset_reg;
+ u8 pwm_register_base;
+ bool pwm_registers_reversed;
+ u8 led_control_register_base;
+ u8 enable_bits_per_led_control_register;
+ int (*reset_func)(struct is31fl32xx_priv *priv);
+ int (*sw_shutdown_func)(struct is31fl32xx_priv *priv, bool enable);
+};
+
+static const struct is31fl32xx_chipdef is31fl3236_cdef = {
+ .channels = 36,
+ .shutdown_reg = 0x00,
+ .pwm_update_reg = 0x25,
+ .global_control_reg = 0x4a,
+ .reset_reg = 0x4f,
+ .pwm_register_base = 0x01,
+ .led_control_register_base = 0x26,
+ .enable_bits_per_led_control_register = 1,
+};
+
+static const struct is31fl32xx_chipdef is31fl3235_cdef = {
+ .channels = 28,
+ .shutdown_reg = 0x00,
+ .pwm_update_reg = 0x25,
+ .global_control_reg = 0x4a,
+ .reset_reg = 0x4f,
+ .pwm_register_base = 0x05,
+ .led_control_register_base = 0x2a,
+ .enable_bits_per_led_control_register = 1,
+};
+
+static const struct is31fl32xx_chipdef is31fl3218_cdef = {
+ .channels = 18,
+ .shutdown_reg = 0x00,
+ .pwm_update_reg = 0x16,
+ .global_control_reg = IS31FL32XX_REG_NONE,
+ .reset_reg = 0x17,
+ .pwm_register_base = 0x01,
+ .led_control_register_base = 0x13,
+ .enable_bits_per_led_control_register = 6,
+};
+
+static int is31fl3216_reset(struct is31fl32xx_priv *priv);
+static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv,
+ bool enable);
+static const struct is31fl32xx_chipdef is31fl3216_cdef = {
+ .channels = 16,
+ .shutdown_reg = IS31FL32XX_REG_NONE,
+ .pwm_update_reg = 0xB0,
+ .global_control_reg = IS31FL32XX_REG_NONE,
+ .reset_reg = IS31FL32XX_REG_NONE,
+ .pwm_register_base = 0x10,
+ .pwm_registers_reversed = true,
+ .led_control_register_base = 0x01,
+ .enable_bits_per_led_control_register = 8,
+ .reset_func = is31fl3216_reset,
+ .sw_shutdown_func = is31fl3216_software_shutdown,
+};
+
+static int is31fl32xx_write(struct is31fl32xx_priv *priv, u8 reg, u8 val)
+{
+ int ret;
+
+ dev_dbg(&priv->client->dev, "writing register 0x%02X=0x%02X", reg, val);
+
+ ret = i2c_smbus_write_byte_data(priv->client, reg, val);
+ if (ret) {
+ dev_err(&priv->client->dev,
+ "register write to 0x%02X failed (error %d)",
+ reg, ret);
+ }
+ return ret;
+}
+
+/*
+ * Custom reset function for IS31FL3216 because it does not have a RESET
+ * register the way that the other IS31FL32xx chips do. We don't bother
+ * writing the GPIO and animation registers, because the registers we
+ * do write ensure those will have no effect.
+ */
+static int is31fl3216_reset(struct is31fl32xx_priv *priv)
+{
+ unsigned int i;
+ int ret;
+
+ ret = is31fl32xx_write(priv, IS31FL3216_CONFIG_REG,
+ IS31FL3216_CONFIG_SSD_ENABLE);
+ if (ret)
+ return ret;
+ for (i = 0; i < priv->cdef->channels; i++) {
+ ret = is31fl32xx_write(priv, priv->cdef->pwm_register_base+i,
+ 0x00);
+ if (ret)
+ return ret;
+ }
+ ret = is31fl32xx_write(priv, priv->cdef->pwm_update_reg, 0);
+ if (ret)
+ return ret;
+ ret = is31fl32xx_write(priv, IS31FL3216_LIGHTING_EFFECT_REG, 0x00);
+ if (ret)
+ return ret;
+ ret = is31fl32xx_write(priv, IS31FL3216_CHANNEL_CONFIG_REG, 0x00);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+/*
+ * Custom Software-Shutdown function for IS31FL3216 because it does not have
+ * a SHUTDOWN register the way that the other IS31FL32xx chips do.
+ * We don't bother doing a read/modify/write on the CONFIG register because
+ * we only ever use a value of '0' for the other fields in that register.
+ */
+static int is31fl3216_software_shutdown(struct is31fl32xx_priv *priv,
+ bool enable)
+{
+ u8 value = enable ? IS31FL3216_CONFIG_SSD_ENABLE :
+ IS31FL3216_CONFIG_SSD_DISABLE;
+
+ return is31fl32xx_write(priv, IS31FL3216_CONFIG_REG, value);
+}
+
+/*
+ * NOTE: A mutex is not needed in this function because:
+ * - All referenced data is read-only after probe()
+ * - The I2C core has a mutex on to protect the bus
+ * - There are no read/modify/write operations
+ * - Intervening operations between the write of the PWM register
+ * and the Update register are harmless.
+ *
+ * Example:
+ * PWM_REG_1 write 16
+ * UPDATE_REG write 0
+ * PWM_REG_2 write 128
+ * UPDATE_REG write 0
+ * vs:
+ * PWM_REG_1 write 16
+ * PWM_REG_2 write 128
+ * UPDATE_REG write 0
+ * UPDATE_REG write 0
+ * are equivalent. Poking the Update register merely applies all PWM
+ * register writes up to that point.
+ */
+static int is31fl32xx_brightness_set(struct led_classdev *led_cdev,
+ enum led_brightness brightness)
+{
+ const struct is31fl32xx_led_data *led_data =
+ container_of(led_cdev, struct is31fl32xx_led_data, cdev);
+ const struct is31fl32xx_chipdef *cdef = led_data->priv->cdef;
+ u8 pwm_register_offset;
+ int ret;
+
+ dev_dbg(led_cdev->dev, "%s: %d\n", __func__, brightness);
+
+ /* NOTE: led_data->channel is 1-based */
+ if (cdef->pwm_registers_reversed)
+ pwm_register_offset = cdef->channels - led_data->channel;
+ else
+ pwm_register_offset = led_data->channel - 1;
+
+ ret = is31fl32xx_write(led_data->priv,
+ cdef->pwm_register_base + pwm_register_offset,
+ brightness);
+ if (ret)
+ return ret;
+
+ return is31fl32xx_write(led_data->priv, cdef->pwm_update_reg, 0);
+}
+
+static int is31fl32xx_reset_regs(struct is31fl32xx_priv *priv)
+{
+ const struct is31fl32xx_chipdef *cdef = priv->cdef;
+ int ret;
+
+ if (cdef->reset_reg != IS31FL32XX_REG_NONE) {
+ ret = is31fl32xx_write(priv, cdef->reset_reg, 0);
+ if (ret)
+ return ret;
+ }
+
+ if (cdef->reset_func)
+ return cdef->reset_func(priv);
+
+ return 0;
+}
+
+static int is31fl32xx_software_shutdown(struct is31fl32xx_priv *priv,
+ bool enable)
+{
+ const struct is31fl32xx_chipdef *cdef = priv->cdef;
+ int ret;
+
+ if (cdef->shutdown_reg != IS31FL32XX_REG_NONE) {
+ u8 value = enable ? IS31FL32XX_SHUTDOWN_SSD_ENABLE :
+ IS31FL32XX_SHUTDOWN_SSD_DISABLE;
+ ret = is31fl32xx_write(priv, cdef->shutdown_reg, value);
+ if (ret)
+ return ret;
+ }
+
+ if (cdef->sw_shutdown_func)
+ return cdef->sw_shutdown_func(priv, enable);
+
+ return 0;
+}
+
+static int is31fl32xx_init_regs(struct is31fl32xx_priv *priv)
+{
+ const struct is31fl32xx_chipdef *cdef = priv->cdef;
+ int ret;
+
+ ret = is31fl32xx_reset_regs(priv);
+ if (ret)
+ return ret;
+
+ /*
+ * Set enable bit for all channels.
+ * We will control state with PWM registers alone.
+ */
+ if (cdef->led_control_register_base != IS31FL32XX_REG_NONE) {
+ u8 value =
+ GENMASK(cdef->enable_bits_per_led_control_register-1, 0);
+ u8 num_regs = cdef->channels /
+ cdef->enable_bits_per_led_control_register;
+ int i;
+
+ for (i = 0; i < num_regs; i++) {
+ ret = is31fl32xx_write(priv,
+ cdef->led_control_register_base+i,
+ value);
+ if (ret)
+ return ret;
+ }
+ }
+
+ ret = is31fl32xx_software_shutdown(priv, false);
+ if (ret)
+ return ret;
+
+ if (cdef->global_control_reg != IS31FL32XX_REG_NONE) {
+ ret = is31fl32xx_write(priv, cdef->global_control_reg, 0x00);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static inline size_t sizeof_is31fl32xx_priv(int num_leds)
+{
+ return sizeof(struct is31fl32xx_priv) +
+ (sizeof(struct is31fl32xx_led_data) * num_leds);
+}
+
+static int is31fl32xx_parse_child_dt(const struct device *dev,
+ const struct device_node *child,
+ struct is31fl32xx_led_data *led_data)
+{
+ struct led_classdev *cdev = &led_data->cdev;
+ int ret = 0;
+ u32 reg;
+
+ if (of_property_read_string(child, "label", &cdev->name))
+ cdev->name = child->name;
+
+ ret = of_property_read_u32(child, "reg", ®);
+ if (ret || reg < 1 || reg > led_data->priv->cdef->channels) {
+ dev_err(dev,
+ "Child node %s does not have a valid reg property\n",
+ child->full_name);
+ return -EINVAL;
+ }
+ led_data->channel = reg;
+
+ of_property_read_string(child, "linux,default-trigger",
+ &cdev->default_trigger);
+
+ cdev->brightness_set_blocking = is31fl32xx_brightness_set;
+
+ return 0;
+}
+
+static struct is31fl32xx_led_data *is31fl32xx_find_led_data(
+ struct is31fl32xx_priv *priv,
+ u8 channel)
+{
+ size_t i;
+
+ for (i = 0; i < priv->num_leds; i++) {
+ if (priv->leds[i].channel == channel)
+ return &priv->leds[i];
+ }
+
+ return NULL;
+}
+
+static int is31fl32xx_parse_dt(struct device *dev,
+ struct is31fl32xx_priv *priv)
+{
+ struct device_node *child;
+ int ret = 0;
+
+ for_each_child_of_node(dev->of_node, child) {
+ struct is31fl32xx_led_data *led_data =
+ &priv->leds[priv->num_leds];
+ const struct is31fl32xx_led_data *other_led_data;
+
+ led_data->priv = priv;
+
+ ret = is31fl32xx_parse_child_dt(dev, child, led_data);
+ if (ret)
+ goto err;
+
+ /* Detect if channel is already in use by another child */
+ other_led_data = is31fl32xx_find_led_data(priv,
+ led_data->channel);
+ if (other_led_data) {
+ dev_err(dev,
+ "%s and %s both attempting to use channel %d\n",
+ led_data->cdev.name,
+ other_led_data->cdev.name,
+ led_data->channel);
+ goto err;
+ }
+
+ ret = devm_led_classdev_register(dev, &led_data->cdev);
+ if (ret) {
+ dev_err(dev, "failed to register PWM led for %s: %d\n",
+ led_data->cdev.name, ret);
+ goto err;
+ }
+
+ priv->num_leds++;
+ }
+
+ return 0;
+
+err:
+ of_node_put(child);
+ return ret;
+}
+
+static const struct of_device_id of_is31fl31xx_match[] = {
+ { .compatible = "issi,is31fl3236", .data = &is31fl3236_cdef, },
+ { .compatible = "issi,is31fl3235", .data = &is31fl3235_cdef, },
+ { .compatible = "issi,is31fl3218", .data = &is31fl3218_cdef, },
+ { .compatible = "issi,is31fl3216", .data = &is31fl3216_cdef, },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, of_is31fl31xx_match);
+
+static int is31fl32xx_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ const struct is31fl32xx_chipdef *cdef;
+ const struct of_device_id *of_dev_id;
+ struct device *dev = &client->dev;
+ struct is31fl32xx_priv *priv;
+ int count;
+ int ret = 0;
+
+ of_dev_id = of_match_device(of_is31fl31xx_match, dev);
+ if (!of_dev_id)
+ return -EINVAL;
+
+ cdef = of_dev_id->data;
+
+ count = of_get_child_count(dev->of_node);
+ if (!count)
+ return -EINVAL;
+
+ priv = devm_kzalloc(dev, sizeof_is31fl32xx_priv(count),
+ GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->client = client;
+ priv->cdef = cdef;
+ i2c_set_clientdata(client, priv);
+
+ ret = is31fl32xx_init_regs(priv);
+ if (ret)
+ return ret;
+
+ ret = is31fl32xx_parse_dt(dev, priv);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int is31fl32xx_remove(struct i2c_client *client)
+{
+ struct is31fl32xx_priv *priv = i2c_get_clientdata(client);
+
+ return is31fl32xx_reset_regs(priv);
+}
+
+/*
+ * i2c-core requires that id_table be non-NULL, even though
+ * it is not used for DeviceTree based instantiation.
+ */
+static const struct i2c_device_id is31fl31xx_id[] = {
+ {},
+};
+
+MODULE_DEVICE_TABLE(i2c, is31fl31xx_id);
+
+static struct i2c_driver is31fl32xx_driver = {
+ .driver = {
+ .name = "is31fl32xx",
+ .of_match_table = of_is31fl31xx_match,
+ },
+ .probe = is31fl32xx_probe,
+ .remove = is31fl32xx_remove,
+ .id_table = is31fl31xx_id,
+};
+
+module_i2c_driver(is31fl32xx_driver);
+
+MODULE_AUTHOR("David Rivshin <drivshin@allworx.com>");
+MODULE_DESCRIPTION("ISSI IS31FL32xx LED driver");
+MODULE_LICENSE("GPL v2");
projects / mirror_ubuntu-artful-kernel.git / commitdiff