Re: [PATCH 1/2] backlight: arcxcnn: add support for ArticSand devices
From: Lee Jones
Date: Thu Nov 10 2016 - 03:12:06 EST
On Wed, 09 Nov 2016, Lee Jones wrote:
> Jingoo?
Ah, it looks like you used the wrong address.
I should have been: jingoohan1@xxxxxxxxx
I'll CC him from here.
> On Wed, 26 Oct 2016, Olimpiu Dejeu wrote:
>
> > Resubmition of arcxcnn backliught driver adding devicetree entries
> > for all registers
> >
> > Signed-off-by: Olimpiu Dejeu <olimpiu@xxxxxxxxxxxxxx>
> >
> > ---
> > 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 <bdodge09@xxxxxxxxxxx>");
> > +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 â Open source software for ARM SoCs
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