diff options
Diffstat (limited to 'drivers/video/backlight/arcxcnn_bl.c')
| -rw-r--r-- | drivers/video/backlight/arcxcnn_bl.c | 419 |
1 files changed, 419 insertions, 0 deletions
diff --git a/drivers/video/backlight/arcxcnn_bl.c b/drivers/video/backlight/arcxcnn_bl.c new file mode 100644 index 000000000..dec790de7 --- /dev/null +++ b/drivers/video/backlight/arcxcnn_bl.c @@ -0,0 +1,419 @@ +/* + * Backlight driver for ArcticSand ARC_X_C_0N_0N Devices + * + * Copyright 2016 ArcticSand, Inc. + * Author : Brian Dodge <bdodge@arcticsand.com> + * + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/backlight.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/slab.h> + +enum arcxcnn_chip_id { + ARC2C0608 +}; + +/** + * struct arcxcnn_platform_data + * @name : Backlight driver name (NULL will use default) + * @initial_brightness : initial value of backlight brightness + * @leden : 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 + */ +struct arcxcnn_platform_data { + const char *name; + u16 initial_brightness; + u8 leden; + u8 led_config_0; + u8 led_config_1; + u8 dim_freq; + u8 comp_config; + u8 filter_config; + u8 trim_config; +}; + +#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) ext. 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_ILED_DIM_PWM 0x00 /* config dim mode pwm */ +#define ARCXCNN_ILED_DIM_INT 0x04 /* config dim mode internal */ +#define ARCXCNN_LEDEN 0x06 /* LED Enable Register */ +#define ARCXCNN_LEDEN_ISETEXT 0x80 /* Full-scale current set extern */ +#define ARCXCNN_LEDEN_MASK 0x3F /* LED string enables mask */ +#define ARCXCNN_LEDEN_BITS 0x06 /* Bits of 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_LSB_SHIFT 0x04 /* ISET LSB Left Shift */ +#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 ARCXCNN_ID_MSB 0x1E +#define ARCXCNN_ID_LSB 0x1F + +#define MAX_BRIGHTNESS 4095 +#define INIT_BRIGHT 60 + +struct arcxcnn { + struct i2c_client *client; + struct backlight_device *bl; + struct device *dev; + struct arcxcnn_platform_data *pdata; +}; + +static int arcxcnn_update_field(struct arcxcnn *lp, u8 reg, u8 mask, u8 data) +{ + int ret; + u8 tmp; + + ret = i2c_smbus_read_byte_data(lp->client, reg); + 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 i2c_smbus_write_byte_data(lp->client, reg, tmp); +} + +static int arcxcnn_set_brightness(struct arcxcnn *lp, u32 brightness) +{ + int ret; + u8 val; + + /* lower nibble of brightness goes in upper nibble of LSB register */ + val = (brightness & 0xF) << ARCXCNN_WLED_ISET_LSB_SHIFT; + ret = i2c_smbus_write_byte_data(lp->client, + ARCXCNN_WLED_ISET_LSB, val); + if (ret < 0) + return ret; + + /* remaining 8 bits of brightness go in MSB register */ + val = (brightness >> 4); + return i2c_smbus_write_byte_data(lp->client, + ARCXCNN_WLED_ISET_MSB, val); +} + +static int arcxcnn_bl_update_status(struct backlight_device *bl) +{ + struct arcxcnn *lp = bl_get_data(bl); + u32 brightness = bl->props.brightness; + int ret; + + if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK)) + brightness = 0; + + ret = arcxcnn_set_brightness(lp, brightness); + if (ret) + return ret; + + /* set power-on/off/save modes */ + return arcxcnn_update_field(lp, ARCXCNN_CMD, ARCXCNN_CMD_STDBY, + (bl->props.power == 0) ? 0 : ARCXCNN_CMD_STDBY); +} + +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_properties *props; + const char *name = lp->pdata->name ? : "arctic_bl"; + + props = devm_kzalloc(lp->dev, sizeof(*props), GFP_KERNEL); + if (!props) + return -ENOMEM; + + props->type = BACKLIGHT_PLATFORM; + props->max_brightness = MAX_BRIGHTNESS; + + if (lp->pdata->initial_brightness > props->max_brightness) + lp->pdata->initial_brightness = props->max_brightness; + + props->brightness = lp->pdata->initial_brightness; + + lp->bl = devm_backlight_device_register(lp->dev, name, lp->dev, lp, + &arcxcnn_bl_ops, props); + return PTR_ERR_OR_ZERO(lp->bl); +} + +static void arcxcnn_parse_dt(struct arcxcnn *lp) +{ + struct device *dev = lp->dev; + struct device_node *node = dev->of_node; + u32 prog_val, num_entry, entry, sources[ARCXCNN_LEDEN_BITS]; + int ret; + + /* device tree entry isn't required, defaults are OK */ + if (!node) + return; + + 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) + lp->pdata->initial_brightness = prog_val; + + ret = of_property_read_u32(node, "arc,led-config-0", &prog_val); + if (ret == 0) + lp->pdata->led_config_0 = (u8)prog_val; + + ret = of_property_read_u32(node, "arc,led-config-1", &prog_val); + if (ret == 0) + lp->pdata->led_config_1 = (u8)prog_val; + + ret = of_property_read_u32(node, "arc,dim-freq", &prog_val); + if (ret == 0) + lp->pdata->dim_freq = (u8)prog_val; + + ret = of_property_read_u32(node, "arc,comp-config", &prog_val); + if (ret == 0) + lp->pdata->comp_config = (u8)prog_val; + + ret = of_property_read_u32(node, "arc,filter-config", &prog_val); + if (ret == 0) + lp->pdata->filter_config = (u8)prog_val; + + ret = of_property_read_u32(node, "arc,trim-config", &prog_val); + if (ret == 0) + lp->pdata->trim_config = (u8)prog_val; + + ret = of_property_count_u32_elems(node, "led-sources"); + if (ret < 0) { + lp->pdata->leden = ARCXCNN_LEDEN_MASK; /* all on is default */ + } else { + num_entry = ret; + if (num_entry > ARCXCNN_LEDEN_BITS) + num_entry = ARCXCNN_LEDEN_BITS; + + 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; + } + + lp->pdata->leden = 0; + + /* for each enable in source, set bit in led enable */ + for (entry = 0; entry < num_entry; entry++) { + u8 onbit = 1 << sources[entry]; + + lp->pdata->leden |= onbit; + } + } +} + +static int arcxcnn_probe(struct i2c_client *cl, const struct i2c_device_id *id) +{ + struct arcxcnn *lp; + int ret; + + 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->pdata = dev_get_platdata(&cl->dev); + + /* reset the device */ + ret = i2c_smbus_write_byte_data(lp->client, + ARCXCNN_CMD, ARCXCNN_CMD_RESET); + if (ret) + goto probe_err; + + if (!lp->pdata) { + lp->pdata = devm_kzalloc(lp->dev, + sizeof(*lp->pdata), GFP_KERNEL); + if (!lp->pdata) + return -ENOMEM; + + /* Setup defaults based on power-on defaults */ + lp->pdata->name = NULL; + lp->pdata->initial_brightness = INIT_BRIGHT; + lp->pdata->leden = ARCXCNN_LEDEN_MASK; + + lp->pdata->led_config_0 = i2c_smbus_read_byte_data( + lp->client, ARCXCNN_FADECTRL); + + lp->pdata->led_config_1 = i2c_smbus_read_byte_data( + lp->client, ARCXCNN_ILED_CONFIG); + /* insure dim mode is not default pwm */ + lp->pdata->led_config_1 |= ARCXCNN_ILED_DIM_INT; + + lp->pdata->dim_freq = i2c_smbus_read_byte_data( + lp->client, ARCXCNN_DIMFREQ); + + lp->pdata->comp_config = i2c_smbus_read_byte_data( + lp->client, ARCXCNN_COMP_CONFIG); + + lp->pdata->filter_config = i2c_smbus_read_byte_data( + lp->client, ARCXCNN_FILT_CONFIG); + + lp->pdata->trim_config = i2c_smbus_read_byte_data( + lp->client, ARCXCNN_IMAXTUNE); + + if (IS_ENABLED(CONFIG_OF)) + arcxcnn_parse_dt(lp); + } + + i2c_set_clientdata(cl, lp); + + /* constrain settings to what is possible */ + if (lp->pdata->initial_brightness > MAX_BRIGHTNESS) + lp->pdata->initial_brightness = MAX_BRIGHTNESS; + + /* set initial brightness */ + ret = arcxcnn_set_brightness(lp, lp->pdata->initial_brightness); + if (ret) + goto probe_err; + + /* set other register values directly */ + ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_FADECTRL, + lp->pdata->led_config_0); + if (ret) + goto probe_err; + + ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_ILED_CONFIG, + lp->pdata->led_config_1); + if (ret) + goto probe_err; + + ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_DIMFREQ, + lp->pdata->dim_freq); + if (ret) + goto probe_err; + + ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_COMP_CONFIG, + lp->pdata->comp_config); + if (ret) + goto probe_err; + + ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_FILT_CONFIG, + lp->pdata->filter_config); + if (ret) + goto probe_err; + + ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_IMAXTUNE, + lp->pdata->trim_config); + if (ret) + goto probe_err; + + /* set initial LED Enables */ + arcxcnn_update_field(lp, ARCXCNN_LEDEN, + ARCXCNN_LEDEN_MASK, lp->pdata->leden); + + ret = arcxcnn_backlight_register(lp); + if (ret) + goto probe_register_err; + + backlight_update_status(lp->bl); + + return 0; + +probe_register_err: + dev_err(lp->dev, + "failed to register backlight.\n"); + +probe_err: + dev_err(lp->dev, + "failure ret: %d\n", ret); + return ret; +} + +static int arcxcnn_remove(struct i2c_client *cl) +{ + struct arcxcnn *lp = i2c_get_clientdata(cl); + + /* disable all strings (ignore errors) */ + i2c_smbus_write_byte_data(lp->client, + ARCXCNN_LEDEN, 0x00); + /* reset the device (ignore errors) */ + i2c_smbus_write_byte_data(lp->client, + ARCXCNN_CMD, ARCXCNN_CMD_RESET); + + lp->bl->props.brightness = 0; + + backlight_update_status(lp->bl); + + return 0; +} + +static const struct of_device_id arcxcnn_dt_ids[] = { + { .compatible = "arc,arc2c0608" }, + { } +}; +MODULE_DEVICE_TABLE(of, arcxcnn_dt_ids); + +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 <bdodge@arcticsand.com>"); +MODULE_DESCRIPTION("ARCXCNN Backlight driver"); |