Jingoo?

On Wed, 26 Oct 2016, Olimpiu Dejeu wrote:

> Resubmition of arcxcnn backliught driver adding devicetree entries
>  for all registers
> 
> Signed-off-by: Olimpiu Dejeu <olim...@arcticsand.com>
> 
> ---
>  drivers/video/backlight/Kconfig      |   7 +
>  drivers/video/backlight/Makefile     |   1 +
>  drivers/video/backlight/arcxcnn_bl.c | 541 
> +++++++++++++++++++++++++++++++++++
>  include/linux/i2c/arcxcnn.h          |  67 +++++
>  4 files changed, 616 insertions(+)
>  create mode 100644 drivers/video/backlight/arcxcnn_bl.c
>  create mode 100644 include/linux/i2c/arcxcnn.h
> 
> diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
> index 5ffa4b4..4e1d2ad 100644
> --- a/drivers/video/backlight/Kconfig
> +++ b/drivers/video/backlight/Kconfig
> @@ -460,6 +460,13 @@ config BACKLIGHT_BD6107
>       help
>         If you have a Rohm BD6107 say Y to enable the backlight driver.
>  
> +config BACKLIGHT_ARCXCNN
> +     tristate "Backlight driver for the Arctic Sands ARCxCnnnn family"
> +     depends on I2C
> +     help
> +       If you have an ARCxCnnnn family backlight say Y to enable
> +       the backlight driver.
> +
>  endif # BACKLIGHT_CLASS_DEVICE
>  
>  endif # BACKLIGHT_LCD_SUPPORT
> diff --git a/drivers/video/backlight/Makefile 
> b/drivers/video/backlight/Makefile
> index 16ec534..8905129 100644
> --- a/drivers/video/backlight/Makefile
> +++ b/drivers/video/backlight/Makefile
> @@ -55,3 +55,4 @@ obj-$(CONFIG_BACKLIGHT_SKY81452)    += sky81452-backlight.o
>  obj-$(CONFIG_BACKLIGHT_TOSA)         += tosa_bl.o
>  obj-$(CONFIG_BACKLIGHT_TPS65217)     += tps65217_bl.o
>  obj-$(CONFIG_BACKLIGHT_WM831X)               += wm831x_bl.o
> +obj-$(CONFIG_BACKLIGHT_ARCXCNN)      += arcxcnn_bl.o
> diff --git a/drivers/video/backlight/arcxcnn_bl.c 
> b/drivers/video/backlight/arcxcnn_bl.c
> new file mode 100644
> index 0000000..1dad680
> --- /dev/null
> +++ b/drivers/video/backlight/arcxcnn_bl.c
> @@ -0,0 +1,541 @@
> +/*
> + * Backlight driver for ArcticSand ARC_X_C_0N_0N Devices
> + *
> + * Copyright 2016 ArcticSand, Inc.
> + *
> + * Licensed under the GPL-2 or later.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/i2c.h>
> +#include <linux/backlight.h>
> +#include <linux/err.h>
> +#include <linux/of.h>
> +#include <linux/pwm.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include "linux/i2c/arcxcnn.h"
> +
> +#define ARCXCNN_CMD          (0x00)  /* Command Register */
> +#define ARCXCNN_CMD_STDBY    (0x80)  /* I2C Standby */
> +#define ARCXCNN_CMD_RESET    (0x40)  /* Reset */
> +#define ARCXCNN_CMD_BOOST    (0x10)  /* Boost */
> +#define ARCXCNN_CMD_OVP_MASK (0x0C)  /* --- Over Voltage Threshold */
> +#define ARCXCNN_CMD_OVP_XXV  (0x0C)  /* <rsvrd> Over Voltage Threshold */
> +#define ARCXCNN_CMD_OVP_20V  (0x08)  /* 20v Over Voltage Threshold */
> +#define ARCXCNN_CMD_OVP_24V  (0x04)  /* 24v Over Voltage Threshold */
> +#define ARCXCNN_CMD_OVP_31V  (0x00)  /* 31.4v Over Voltage Threshold */
> +#define ARCXCNN_CMD_EXT_COMP (0x01)  /* part (0) or full (1) external comp */
> +
> +#define ARCXCNN_CONFIG       (0x01)  /* Configuration */
> +#define ARCXCNN_STATUS1      (0x02)  /* Status 1 */
> +#define ARCXCNN_STATUS2      (0x03)  /* Status 2 */
> +#define ARCXCNN_FADECTRL     (0x04)  /* Fading Control */
> +#define ARCXCNN_ILED_CONFIG  (0x05)  /* ILED Configuration */
> +
> +#define ARCXCNN_LEDEN                (0x06)  /* LED Enable Register */
> +#define ARCXCNN_LEDEN_ISETEXT        (0x80)  /* Full-scale current set 
> externally */
> +#define ARCXCNN_LEDEN_MASK   (0x3F)  /* LED string enables */
> +#define ARCXCNN_LEDEN_LED1   (0x01)
> +#define ARCXCNN_LEDEN_LED2   (0x02)
> +#define ARCXCNN_LEDEN_LED3   (0x04)
> +#define ARCXCNN_LEDEN_LED4   (0x08)
> +#define ARCXCNN_LEDEN_LED5   (0x10)
> +#define ARCXCNN_LEDEN_LED6   (0x20)
> +
> +#define ARCXCNN_WLED_ISET_LSB        (0x07)  /* LED ISET LSB (in upper 
> nibble) */
> +#define ARCXCNN_WLED_ISET_MSB        (0x08)  /* LED ISET MSB (8 bits) */
> +
> +#define ARCXCNN_DIMFREQ              (0x09)
> +#define ARCXCNN_COMP_CONFIG  (0x0A)
> +#define ARCXCNN_FILT_CONFIG  (0x0B)
> +#define ARCXCNN_IMAXTUNE     (0x0C)
> +
> +#define DEFAULT_BL_NAME              "arctic_bl"
> +#define MAX_BRIGHTNESS               4095
> +
> +static int s_no_reset_on_remove;
> +module_param_named(noreset, s_no_reset_on_remove, int, 0644);
> +MODULE_PARM_DESC(noreset, "No reset on module removal");
> +
> +static int s_ibright = 60;
> +module_param_named(ibright, s_ibright, int, 0644);
> +MODULE_PARM_DESC(ibright, "Initial brightness (when no plat data)");
> +
> +static int s_iledstr = 0x3F;
> +module_param_named(iledstr, s_iledstr, int, 0644);
> +MODULE_PARM_DESC(iledstr, "Initial LED String (when no plat data)");
> +
> +static int s_retries = 2; /* 1 == only one try */
> +module_param_named(retries, s_retries, int, 0644);
> +MODULE_PARM_DESC(retries, "I2C retries attempted");
> +
> +enum arcxcnn_brightness_ctrl_mode {
> +     PWM_BASED = 1,
> +     REGISTER_BASED,
> +};
> +
> +struct arcxcnn;
> +
> +struct arcxcnn {
> +     char chipname[64];
> +     enum arcxcnn_chip_id chip_id;
> +     enum arcxcnn_brightness_ctrl_mode mode;
> +     struct i2c_client *client;
> +     struct backlight_device *bl;
> +     struct device *dev;
> +     struct arcxcnn_platform_data *pdata;
> +     struct pwm_device *pwm;
> +     struct regulator *supply;       /* regulator for VDD input */
> +};
> +
> +static int arcxcnn_write_byte(struct arcxcnn *lp, u8 reg, u8 data)
> +{
> +     s32 ret = -1;
> +     int att;
> +
> +     for (att = 0; att < s_retries; att++) {
> +             ret = i2c_smbus_write_byte_data(lp->client, reg, data);
> +             if (ret >= 0)
> +                     return 0;
> +     }
> +     return ret;
> +}
> +
> +static u8 arcxcnn_read_byte(struct arcxcnn *lp, u8 reg)
> +{
> +     int val;
> +     int att;
> +
> +     for (att = 0; att < s_retries; att++) {
> +             val = i2c_smbus_read_byte_data(lp->client, reg);
> +             if (val >= 0)
> +                     return (u8)val;
> +     }
> +     return 0;
> +}
> +
> +static int arcxcnn_update_bit(struct arcxcnn *lp, u8 reg, u8 mask, u8 data)
> +{
> +     int ret, att;
> +     u8 tmp;
> +
> +     for (att = 0, ret = -1; att < s_retries; att++) {
> +             ret = i2c_smbus_read_byte_data(lp->client, reg);
> +             if (ret >= 0)
> +                     break;
> +     }
> +     if (ret < 0) {
> +             dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
> +             return ret;
> +     }
> +
> +     tmp = (u8)ret;
> +     tmp &= ~mask;
> +     tmp |= data & mask;
> +
> +     return arcxcnn_write_byte(lp, reg, tmp);
> +}
> +
> +static int arcxcnn_set_brightness(struct arcxcnn *lp, u32 brightness)
> +{
> +     int ret;
> +     u8 val;
> +
> +     val = (brightness & 0xF) << 4;
> +     ret = arcxcnn_write_byte(lp, ARCXCNN_WLED_ISET_LSB, val);
> +     if (ret < 0)
> +             return ret;
> +     val = (brightness >> 4);
> +     ret = arcxcnn_write_byte(lp, ARCXCNN_WLED_ISET_MSB, val);
> +     return ret;
> +}
> +
> +static int arcxcnn_bl_update_status(struct backlight_device *bl)
> +{
> +     struct arcxcnn *lp = bl_get_data(bl);
> +     u32 brightness = bl->props.brightness;
> +
> +     if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
> +             brightness = 0;
> +
> +     /* set brightness */
> +     if (lp->mode == PWM_BASED)
> +             ; /* via pwm */
> +     else if (lp->mode == REGISTER_BASED)
> +             arcxcnn_set_brightness(lp, brightness);
> +
> +     /* set power-on/off/save modes */
> +     if (bl->props.power == 0)
> +             /* take out of standby */
> +             arcxcnn_update_bit(lp, ARCXCNN_CMD, ARCXCNN_CMD_STDBY, 0);
> +     else
> +             /* 1-3 == power save, 4 = off
> +              * place in low-power standby mode
> +              */
> +             arcxcnn_update_bit(lp, ARCXCNN_CMD,
> +                             ARCXCNN_CMD_STDBY, ARCXCNN_CMD_STDBY);
> +     return 0;
> +}
> +
> +static const struct backlight_ops arcxcnn_bl_ops = {
> +     .options = BL_CORE_SUSPENDRESUME,
> +     .update_status = arcxcnn_bl_update_status,
> +};
> +
> +static int arcxcnn_backlight_register(struct arcxcnn *lp)
> +{
> +     struct backlight_device *bl;
> +     struct backlight_properties props;
> +     struct arcxcnn_platform_data *pdata = lp->pdata;
> +     const char *name = pdata->name ? : DEFAULT_BL_NAME;
> +
> +     memset(&props, 0, sizeof(props));
> +     props.type = BACKLIGHT_PLATFORM;
> +     props.max_brightness = MAX_BRIGHTNESS;
> +
> +     if (pdata->initial_brightness > props.max_brightness)
> +             pdata->initial_brightness = props.max_brightness;
> +
> +     props.brightness = pdata->initial_brightness;
> +
> +     bl = devm_backlight_device_register(lp->dev, name, lp->dev, lp,
> +                                    &arcxcnn_bl_ops, &props);
> +     if (IS_ERR(bl))
> +             return PTR_ERR(bl);
> +
> +     lp->bl = bl;
> +
> +     return 0;
> +}
> +
> +static ssize_t arcxcnn_get_chip_id(struct device *dev,
> +             struct device_attribute *attr, char *buf)
> +{
> +     struct arcxcnn *lp = dev_get_drvdata(dev);
> +
> +     return scnprintf(buf, PAGE_SIZE, "%s\n", lp->chipname);
> +}
> +
> +static ssize_t arcxcnn_get_led_str(struct device *dev,
> +             struct device_attribute *attr, char *buf)
> +{
> +     struct arcxcnn *lp = dev_get_drvdata(dev);
> +
> +     return scnprintf(buf, PAGE_SIZE, "%02X\n", lp->pdata->led_str);
> +}
> +
> +static ssize_t arcxcnn_set_led_str(struct device *dev,
> +             struct device_attribute *attr, const char *buf, size_t len)
> +{
> +     struct arcxcnn *lp = dev_get_drvdata(dev);
> +     unsigned long ledstr;
> +
> +     if (kstrtoul(buf, 0, &ledstr))
> +             return 0;
> +
> +     if (ledstr != lp->pdata->led_str) {
> +             /* don't allow 0 for ledstr, use power to turn all off */
> +             if (ledstr == 0)
> +                     return 0;
> +             lp->pdata->led_str = ledstr & 0x3F;
> +             arcxcnn_update_bit(lp, ARCXCNN_LEDEN,
> +                     ARCXCNN_LEDEN_MASK, lp->pdata->led_str);
> +     }
> +     return len;
> +}
> +
> +static ssize_t arcxcnn_get_bl_ctl_mode(struct device *dev,
> +          struct device_attribute *attr, char *buf)
> +{
> +     struct arcxcnn *lp = dev_get_drvdata(dev);
> +     char *strmode = NULL;
> +
> +     if (lp->mode == PWM_BASED)
> +             strmode = "pwm based";
> +     else if (lp->mode == REGISTER_BASED)
> +             strmode = "register based";
> +
> +     return scnprintf(buf, PAGE_SIZE, "%s\n", strmode);
> +}
> +
> +static DEVICE_ATTR(chip_id, 0444, arcxcnn_get_chip_id, NULL);
> +static DEVICE_ATTR(led_str, 0664, arcxcnn_get_led_str, arcxcnn_set_led_str);
> +static DEVICE_ATTR(bl_ctl_mode, 0444, arcxcnn_get_bl_ctl_mode, NULL);
> +
> +static struct attribute *arcxcnn_attributes[] = {
> +     &dev_attr_chip_id.attr,
> +     &dev_attr_led_str.attr,
> +     &dev_attr_bl_ctl_mode.attr,
> +     NULL,
> +};
> +
> +static const struct attribute_group arcxcnn_attr_group = {
> +     .attrs = arcxcnn_attributes,
> +};
> +
> +#ifdef CONFIG_OF
> +static int arcxcnn_parse_dt(struct arcxcnn *lp)
> +{
> +     struct device *dev = lp->dev;
> +     struct device_node *node = dev->of_node;
> +     u32 prog_val, num_entry, sources[6];
> +     int ret;
> +
> +     if (!node) {
> +             dev_err(dev, "no platform data.\n");
> +             return -EINVAL;
> +     }
> +     lp->pdata->led_config_0_set = false;
> +     lp->pdata->led_config_1_set = false;
> +     lp->pdata->dim_freq_set = false;
> +     lp->pdata->comp_config_set = false;
> +     lp->pdata->filter_config_set = false;
> +     lp->pdata->trim_config_set = false;
> +
> +     ret = of_property_read_string(node, "label", &lp->pdata->name);
> +     if (ret < 0)
> +             lp->pdata->name = NULL;
> +
> +     ret = of_property_read_u32(node, "default-brightness", &prog_val);
> +     if (ret < 0)
> +             prog_val = s_ibright;
> +     lp->pdata->initial_brightness = prog_val;
> +     if (lp->pdata->initial_brightness > MAX_BRIGHTNESS)
> +             lp->pdata->initial_brightness = MAX_BRIGHTNESS;
> +
> +     ret = of_property_read_u32(node, "arcticsand,led-config-0", &prog_val);
> +     if (ret == 0) {
> +             lp->pdata->led_config_0 = (u8)prog_val;
> +             lp->pdata->led_config_0_set = true;
> +     }
> +     ret = of_property_read_u32(node, "arcticsand,led-config-1", &prog_val);
> +     if (ret == 0) {
> +             lp->pdata->led_config_1 = (u8)prog_val;
> +             lp->pdata->led_config_1_set = true;
> +     }
> +     ret = of_property_read_u32(node, "arcticsand,dim-freq", &prog_val);
> +     if (ret == 0) {
> +             lp->pdata->dim_freq = (u8)prog_val;
> +             lp->pdata->dim_freq_set = true;
> +     }
> +     ret = of_property_read_u32(node, "arcticsand,comp-config", &prog_val);
> +     if (ret == 0) {
> +             lp->pdata->comp_config = (u8)prog_val;
> +             lp->pdata->comp_config_set = true;
> +     }
> +     ret = of_property_read_u32(node, "arcticsand,filter-config", &prog_val);
> +     if (ret == 0) {
> +             lp->pdata->filter_config = (u8)prog_val;
> +             lp->pdata->filter_config_set = true;
> +     }
> +     ret = of_property_read_u32(node, "arcticsand,trim-config", &prog_val);
> +     if (ret == 0) {
> +             lp->pdata->trim_config = (u8)prog_val;
> +             lp->pdata->trim_config_set = true;
> +     }
> +     ret = of_property_count_u32_elems(node, "led-sources");
> +     if (ret < 0)
> +             lp->pdata->led_str = 0x3F;
> +     else {
> +             num_entry = ret;
> +             if (num_entry > 6)
> +                     num_entry = 6;
> +
> +             ret = of_property_read_u32_array(node, "led-sources", sources,
> +                                     num_entry);
> +             if (ret < 0) {
> +                     dev_err(dev, "led-sources node is invalid.\n");
> +                     return -EINVAL;
> +             }
> +
> +             lp->pdata->led_str = 0;
> +             while (num_entry > 0)
> +                     lp->pdata->led_str |= (1 << sources[--num_entry]);
> +     }
> +     return 0;
> +}
> +#else
> +static int arcxcnn_parse_dt(struct arcxcnn *lp)
> +{
> +     return -EINVAL;
> +}
> +#endif
> +
> +static int arcxcnn_probe(struct i2c_client *cl, const struct i2c_device_id 
> *id)
> +{
> +     struct arcxcnn *lp;
> +     int ret;
> +     u8 regval;
> +     u16 chipid;
> +
> +     if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
> +             return -EIO;
> +
> +     lp = devm_kzalloc(&cl->dev, sizeof(*lp), GFP_KERNEL);
> +     if (!lp)
> +             return -ENOMEM;
> +
> +     lp->client = cl;
> +     lp->dev = &cl->dev;
> +     lp->chip_id = id->driver_data;
> +     lp->pdata = dev_get_platdata(&cl->dev);
> +
> +     if (!lp->pdata) {
> +             lp->pdata = devm_kzalloc(lp->dev,
> +                             sizeof(*lp->pdata), GFP_KERNEL);
> +             if (!lp->pdata)
> +                     return -ENOMEM;
> +
> +             /* no platform data, parse the device-tree for info.  if there
> +              * is no device tree entry, we are being told we exist because
> +              * user-land said so, so make up the info we need
> +              */
> +             ret = arcxcnn_parse_dt(lp);
> +             if (ret < 0) {
> +                     /* no device tree, use defaults based on module params
> +                      */
> +                     lp->pdata->led_config_0_set = false;
> +                     lp->pdata->led_config_1_set = false;
> +                     lp->pdata->dim_freq_set = false;
> +                     lp->pdata->comp_config_set = false;
> +                     lp->pdata->filter_config_set = false;
> +                     lp->pdata->trim_config_set = false;
> +
> +                     lp->pdata->name = NULL;
> +                     lp->pdata->initial_brightness = s_ibright;
> +                     lp->pdata->led_str = s_iledstr;
> +             }
> +     }
> +
> +     if (lp->pdata->dim_freq_set)
> +             lp->mode = PWM_BASED;
> +     else
> +             lp->mode = REGISTER_BASED;
> +
> +     i2c_set_clientdata(cl, lp);
> +
> +     /* read device ID */
> +     regval = arcxcnn_read_byte(lp, 0x1E);
> +     chipid = regval;
> +     chipid <<= 8;
> +     regval = arcxcnn_read_byte(lp, 0x1F);
> +     chipid |= regval;
> +
> +     /* make sure it belongs to this driver
> +      * TODO - handle specific ids
> +      */
> +     if (chipid != 0x02A5) {
> +             #if 1
> +             dev_info(&cl->dev, "Chip Id is %04X\n", chipid);
> +             #else
> +             dev_err(&cl->dev, "%04X is not ARC2C\n", chipid);
> +             return -ENODEV;
> +             #endif
> +     }
> +     /* reset the device */
> +     arcxcnn_write_byte(lp, ARCXCNN_CMD, ARCXCNN_CMD_RESET);
> +
> +     /* set initial brightness */
> +     arcxcnn_set_brightness(lp, lp->pdata->initial_brightness);
> +
> +     /* if fadectrl set in DT, set the value directly, else leave default */
> +     if (lp->pdata->led_config_0_set)
> +             arcxcnn_write_byte(lp, ARCXCNN_FADECTRL,
> +                     lp->pdata->led_config_0);
> +
> +     /* if iled config set in DT, set the value, else internal mode */
> +     if (lp->pdata->led_config_1_set)
> +             arcxcnn_write_byte(lp, ARCXCNN_ILED_CONFIG,
> +                     lp->pdata->led_config_1);
> +     else
> +             arcxcnn_write_byte(lp, ARCXCNN_ILED_CONFIG, 0x57);
> +
> +     /* other misc DT settings */
> +     if (lp->pdata->dim_freq_set)
> +             arcxcnn_write_byte(lp, ARCXCNN_FADECTRL, lp->pdata->dim_freq);
> +     if (lp->pdata->comp_config_set)
> +             arcxcnn_write_byte(lp, ARCXCNN_COMP_CONFIG,
> +                     lp->pdata->comp_config);
> +     if (lp->pdata->filter_config_set)
> +             arcxcnn_write_byte(lp, ARCXCNN_FILT_CONFIG,
> +                     lp->pdata->filter_config);
> +     if (lp->pdata->trim_config_set)
> +             arcxcnn_write_byte(lp, ARCXCNN_IMAXTUNE,
> +                     lp->pdata->trim_config);
> +
> +     /* set initial LED Strings */
> +     arcxcnn_update_bit(lp, ARCXCNN_LEDEN,
> +             ARCXCNN_LEDEN_MASK, lp->pdata->led_str);
> +
> +     snprintf(lp->chipname, sizeof(lp->chipname),
> +             "%s-%04X", id->name, chipid);
> +
> +     ret = arcxcnn_backlight_register(lp);
> +     if (ret) {
> +             dev_err(lp->dev,
> +                     "failed to register backlight. err: %d\n", ret);
> +             return ret;
> +     }
> +
> +     ret = sysfs_create_group(&lp->dev->kobj, &arcxcnn_attr_group);
> +     if (ret) {
> +             dev_err(lp->dev, "failed to register sysfs. err: %d\n", ret);
> +             return ret;
> +     }
> +
> +     backlight_update_status(lp->bl);
> +     return 0;
> +}
> +
> +static int arcxcnn_remove(struct i2c_client *cl)
> +{
> +     struct arcxcnn *lp = i2c_get_clientdata(cl);
> +
> +     if (!s_no_reset_on_remove) {
> +             /* disable all strings */
> +             arcxcnn_write_byte(lp, ARCXCNN_LEDEN, 0x00);
> +             /* reset the device */
> +             arcxcnn_write_byte(lp, ARCXCNN_CMD, ARCXCNN_CMD_RESET);
> +     }
> +     lp->bl->props.brightness = 0;
> +     backlight_update_status(lp->bl);
> +     if (lp->supply)
> +             regulator_disable(lp->supply);
> +     sysfs_remove_group(&lp->dev->kobj, &arcxcnn_attr_group);
> +
> +     return 0;
> +}
> +
> +static const struct of_device_id arcxcnn_dt_ids[] = {
> +     { .compatible = "arc,arc2c0608" },
> +     { }
> +};
> +MODULE_DEVICE_TABLE(of, arcxcnn_dt_ids);
> +
> +/* Note that the device/chip ID is not fixed in silicon so
> + * auto-probing of these devices on the bus is most likely
> + * not possible, use device tree to set i2c bus address
> + */
> +static const struct i2c_device_id arcxcnn_ids[] = {
> +     {"arc2c0608", ARC2C0608},
> +     { }
> +};
> +MODULE_DEVICE_TABLE(i2c, arcxcnn_ids);
> +
> +static struct i2c_driver arcxcnn_driver = {
> +     .driver = {
> +                .name = "arcxcnn_bl",
> +                .of_match_table = of_match_ptr(arcxcnn_dt_ids),
> +                },
> +     .probe = arcxcnn_probe,
> +     .remove = arcxcnn_remove,
> +     .id_table = arcxcnn_ids,
> +};
> +
> +module_i2c_driver(arcxcnn_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Brian Dodge <bdodg...@outlook.com>");
> +MODULE_DESCRIPTION("ARCXCNN Backlight driver");
> diff --git a/include/linux/i2c/arcxcnn.h b/include/linux/i2c/arcxcnn.h
> new file mode 100644
> index 0000000..1c681dd
> --- /dev/null
> +++ b/include/linux/i2c/arcxcnn.h
> @@ -0,0 +1,67 @@
> +/*
> + * Backlight driver for ArcticSand ARC2C0608 Backlight Devices
> + *
> + * Copyright 2016 ArcticSand, Inc.
> + *
> + * Licensed under the GPL-2 or later.
> + */
> +
> +#ifndef _ARCXCNN_H
> +#define _ARCXCNN_H
> +
> +enum arcxcnn_chip_id {
> +     ARC2C0608
> +};
> +
> +enum arcxcnn_brightness_source {
> +     ARCXCNN_PWM_ONLY,
> +     ARCXCNN_I2C_ONLY = 2,
> +};
> +
> +#define ARCXCNN_MAX_PROGENTRIES      48      /* max a/v pairs for custom */
> +
> +/**
> + * struct arcxcnn_platform_data
> + * @name : Backlight driver name. If it is not defined, default name is set.
> + * @initial_brightness : initial value of backlight brightness
> + * @led_str   : initial LED string enables, upper bit is global on/off
> + * @led_config_0 : fading speed (period between intensity steps)
> + * @led_config_1 : misc settings, see datasheet
> + * @dim_freq  : pwm dimming frequency if in pwm mode
> + * @comp_config       : misc config, see datasheet
> + * @filter_config: RC/PWM filter config, see datasheet
> + * @trim_config       : full scale current trim, see datasheet
> + * @led_config_0_set : the value in led_config_0 is valid
> + * @led_config_1_set : the value in led_config_1 is valid
> + * @dim_freq_set     : the value in dim_freq is valid
> + * @comp_config_set  : the value in comp_config is valid
> + * @filter_config_set        : the value in filter_config is valid
> + * @trim_config_set  : the value in trim_config is valid
> + *
> + * the _set flags are used to indicate that the value was explicitly set
> + * in the device tree or platform data. settings not set are left as default
> + * power-on default values of the chip except for led_str and led_config_1
> + * which are set by the driver (led_str is specified indirectly in the
> + * device tree via "led-sources")
> + */
> +struct arcxcnn_platform_data {
> +     const char *name;
> +     u16 initial_brightness;
> +     u8      led_str;
> +
> +     u8      led_config_0;
> +     u8      led_config_1;
> +     u8      dim_freq;
> +     u8      comp_config;
> +     u8      filter_config;
> +     u8      trim_config;
> +
> +     bool    led_config_0_set;
> +     bool    led_config_1_set;
> +     bool    dim_freq_set;
> +     bool    comp_config_set;
> +     bool    filter_config_set;
> +     bool    trim_config_set;
> +};
> +
> +#endif

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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