Re-submission of arcxcnn backlight driver addressing the naming convention concerns raised by Rob H. 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, "arc,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, "arc,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, "arc,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, "arc,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, "arc,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, "arc,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 -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html