Jingoo, Are you still reviewing Backlight patches?
> This is the driver for the Arctic Sand Technologies Inc. ARCXCNN LED > backlight IC family > > Signed-off-by: Olimpiu Dejeu <[email protected]> > > --- > drivers/video/backlight/Kconfig | 7 + > drivers/video/backlight/Makefile | 1 + > drivers/video/backlight/arcxcnn_bl.c | 510 > +++++++++++++++++++++++++++++++++++ > include/linux/i2c/arcxcnn.h | 42 +++ > 4 files changed, 560 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 5a3eb2e..19ee87d 100644 > --- a/drivers/video/backlight/Kconfig > +++ b/drivers/video/backlight/Kconfig > @@ -444,6 +444,13 @@ 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 bb82002..9d7f3ec 100644 > --- a/drivers/video/backlight/Makefile > +++ b/drivers/video/backlight/Makefile > @@ -53,3 +53,4 @@ obj-$(CONFIG_BACKLIGHT_SAHARA) += kb3886_bl.o > obj-$(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..7adfca3 > --- /dev/null > +++ b/drivers/video/backlight/arcxcnn_bl.c > @@ -0,0 +1,510 @@ > +/* > + * Backlight driver for Arctic Sands ARC_X_C_0N_0N Devices > + * > + * Copyright 2016 Arctic Sands 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 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 void arcxcnn_pwm_ctrl(struct arcxcnn *lp, int br, int max_br) > +{ > + unsigned int period = lp->pdata->period_ns; > + unsigned int duty = br * period / max_br; > + struct pwm_device *pwm; > + > + /* request pwm device with the consumer name */ > + if (!lp->pwm) { > + pwm = devm_pwm_get(lp->dev, lp->chipname); > + if (IS_ERR(pwm)) > + return; > + > + lp->pwm = pwm; > + } > + > + pwm_config(lp->pwm, duty, period); > + if (duty) > + pwm_enable(lp->pwm); > + else > + pwm_disable(lp->pwm); > +} > + > +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) > + arcxcnn_pwm_ctrl(lp, brightness, bl->props.max_brightness); > + 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->ledstr); > +} > + > +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->ledstr) { > + /* don't allow 0 for ledstr, use power to turn all off */ > + if (ledstr == 0) > + return 0; > + lp->pdata->ledstr = ledstr & 0x3F; > + arcxcnn_update_bit(lp, ARCXCNN_LEDEN, > + ARCXCNN_LEDEN_MASK, lp->pdata->ledstr); > + } > + 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_length, prog_val; > + > + if (!node) { > + dev_err(dev, "no platform data\n"); > + return -EINVAL; > + } > + > + of_property_read_string(node, "bl-name", &lp->pdata->name); > + of_property_read_u32(node, "init-brt", &prog_val); > + lp->pdata->initial_brightness = prog_val; > + of_property_read_u32(node, "pwm-period", &lp->pdata->period_ns); > + > + if (lp->pdata->initial_brightness > MAX_BRIGHTNESS) > + lp->pdata->initial_brightness = MAX_BRIGHTNESS; > + > + /* Fill program from platform data if defined > + */ > + lp->pdata->prog_entries = 0; > + prog_length = of_get_child_count(node); > + if (prog_length > 0) { > + struct device_node *child; > + u32 i = 0; > + > + for_each_child_of_node(node, child) { > + if (i >= ARCXCNN_MAX_PROGENTRIES) > + break; > + of_property_read_u32(child, "prg-addr", &prog_val); > + lp->pdata->prog_addr[i] = (u8)prog_val; > + of_property_read_u32(child, "prg-data", &prog_val); > + lp->pdata->prog_data[i] = (u8)prog_val; > + i++; > + } > + lp->pdata->prog_entries = i; > + } > + 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; > + u32 i; > + 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 parms > + */ > + lp->pdata->name = NULL; > + lp->pdata->initial_brightness = s_ibright; > + lp->pdata->ledstr = s_iledstr; > + lp->pdata->period_ns = 0; > + lp->pdata->prog_entries = 0; > + > + /* example of prog use: uncomment to test > + lp->pdata->prog_addr[0] = 0x06; > + lp->pdata->prog_data[0] = 0x15; > + lp->pdata->prog_entries = 1; > + */ > + } > + } > + > + if (lp->pdata->period_ns > 0) > + 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); > + > + /* enable internal register mode for brightness */ > + arcxcnn_write_byte(lp, ARCXCNN_ILED_CONFIG, 0x57); > + > + /* set initial LED Strings */ > + arcxcnn_update_bit(lp, ARCXCNN_LEDEN, > + ARCXCNN_LEDEN_MASK, lp->pdata->ledstr); > + > + 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; > + } > + > + /* playback program now that its all installed */ > + for (i = 0; i < lp->pdata->prog_entries; i++) { > + arcxcnn_write_byte(lp, lp->pdata->prog_addr[i], > + lp->pdata->prog_data[i]); > + /* > + printk(KERN_ALERT "%02X, %02X\n", > + lp->pdata->prog_addr[i], lp->pdata->prog_data[i]); > + */ > + } > + > + 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,arcxcnn" }, > + { .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[] = { > + {"arcxcnn", ARCXCNN}, > + {"arc2c0608", ARC2C0608}, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, arcxcnn_ids); > + > +static struct i2c_driver arcxcnn_driver = { > + .driver = { > + .name = "arcxcnn", > + .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 <[email protected]>"); > +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..a9b7922 > --- /dev/null > +++ b/include/linux/i2c/arcxcnn.h > @@ -0,0 +1,42 @@ > +/* > + * Backlight driver for Arctic Sands ARC2C0608 Backlight Devices > + * > + * Copyright 2016 Arctic Sands Inc. > + * > + * Licensed under the GPL-2 or later. > + */ > + > +#ifndef _ARCXCNN_H > +#define _ARCXCNN_H > + > +enum arcxcnn_chip_id { > + ARCXCNN, > + 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 > + * @period_ns : platform specific pwm period value. unit is nano. > + Only valid when mode is PWM_BASED. > + * @led_str : initial LED string > + */ > +struct arcxcnn_platform_data { > + const char *name; > + u16 initial_brightness; > + unsigned int period_ns; > + u8 ledstr; > + u8 prog_addr[ARCXCNN_MAX_PROGENTRIES]; > + u8 prog_data[ARCXCNN_MAX_PROGENTRIES]; > + u32 prog_entries; > +}; > + > +#endif -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
