404 lines
11 KiB
C
404 lines
11 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Backlight driver for ArcticSand ARC_X_C_0N_0N Devices
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*
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* Copyright 2016 ArcticSand, Inc.
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* Author : Brian Dodge <bdodge@arcticsand.com>
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*/
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#include <linux/backlight.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/slab.h>
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enum arcxcnn_chip_id {
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ARC2C0608
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};
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/**
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* struct arcxcnn_platform_data
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* @name : Backlight driver name (NULL will use default)
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* @initial_brightness : initial value of backlight brightness
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* @leden : initial LED string enables, upper bit is global on/off
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* @led_config_0 : fading speed (period between intensity steps)
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* @led_config_1 : misc settings, see datasheet
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* @dim_freq : pwm dimming frequency if in pwm mode
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* @comp_config : misc config, see datasheet
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* @filter_config : RC/PWM filter config, see datasheet
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* @trim_config : full scale current trim, see datasheet
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*/
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struct arcxcnn_platform_data {
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const char *name;
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u16 initial_brightness;
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u8 leden;
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u8 led_config_0;
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u8 led_config_1;
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u8 dim_freq;
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u8 comp_config;
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u8 filter_config;
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u8 trim_config;
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};
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#define ARCXCNN_CMD 0x00 /* Command Register */
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#define ARCXCNN_CMD_STDBY 0x80 /* I2C Standby */
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#define ARCXCNN_CMD_RESET 0x40 /* Reset */
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#define ARCXCNN_CMD_BOOST 0x10 /* Boost */
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#define ARCXCNN_CMD_OVP_MASK 0x0C /* --- Over Voltage Threshold */
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#define ARCXCNN_CMD_OVP_XXV 0x0C /* <rsvrd> Over Voltage Threshold */
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#define ARCXCNN_CMD_OVP_20V 0x08 /* 20v Over Voltage Threshold */
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#define ARCXCNN_CMD_OVP_24V 0x04 /* 24v Over Voltage Threshold */
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#define ARCXCNN_CMD_OVP_31V 0x00 /* 31.4v Over Voltage Threshold */
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#define ARCXCNN_CMD_EXT_COMP 0x01 /* part (0) or full (1) ext. comp */
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#define ARCXCNN_CONFIG 0x01 /* Configuration */
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#define ARCXCNN_STATUS1 0x02 /* Status 1 */
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#define ARCXCNN_STATUS2 0x03 /* Status 2 */
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#define ARCXCNN_FADECTRL 0x04 /* Fading Control */
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#define ARCXCNN_ILED_CONFIG 0x05 /* ILED Configuration */
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#define ARCXCNN_ILED_DIM_PWM 0x00 /* config dim mode pwm */
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#define ARCXCNN_ILED_DIM_INT 0x04 /* config dim mode internal */
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#define ARCXCNN_LEDEN 0x06 /* LED Enable Register */
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#define ARCXCNN_LEDEN_ISETEXT 0x80 /* Full-scale current set extern */
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#define ARCXCNN_LEDEN_MASK 0x3F /* LED string enables mask */
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#define ARCXCNN_LEDEN_BITS 0x06 /* Bits of LED string enables */
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#define ARCXCNN_LEDEN_LED1 0x01
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#define ARCXCNN_LEDEN_LED2 0x02
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#define ARCXCNN_LEDEN_LED3 0x04
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#define ARCXCNN_LEDEN_LED4 0x08
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#define ARCXCNN_LEDEN_LED5 0x10
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#define ARCXCNN_LEDEN_LED6 0x20
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#define ARCXCNN_WLED_ISET_LSB 0x07 /* LED ISET LSB (in upper nibble) */
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#define ARCXCNN_WLED_ISET_LSB_SHIFT 0x04 /* ISET LSB Left Shift */
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#define ARCXCNN_WLED_ISET_MSB 0x08 /* LED ISET MSB (8 bits) */
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#define ARCXCNN_DIMFREQ 0x09
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#define ARCXCNN_COMP_CONFIG 0x0A
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#define ARCXCNN_FILT_CONFIG 0x0B
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#define ARCXCNN_IMAXTUNE 0x0C
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#define ARCXCNN_ID_MSB 0x1E
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#define ARCXCNN_ID_LSB 0x1F
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#define MAX_BRIGHTNESS 4095
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#define INIT_BRIGHT 60
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struct arcxcnn {
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struct i2c_client *client;
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struct backlight_device *bl;
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struct device *dev;
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struct arcxcnn_platform_data *pdata;
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};
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static int arcxcnn_update_field(struct arcxcnn *lp, u8 reg, u8 mask, u8 data)
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{
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int ret;
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u8 tmp;
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ret = i2c_smbus_read_byte_data(lp->client, reg);
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if (ret < 0) {
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dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
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return ret;
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}
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tmp = (u8)ret;
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tmp &= ~mask;
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tmp |= data & mask;
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return i2c_smbus_write_byte_data(lp->client, reg, tmp);
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}
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static int arcxcnn_set_brightness(struct arcxcnn *lp, u32 brightness)
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{
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int ret;
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u8 val;
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/* lower nibble of brightness goes in upper nibble of LSB register */
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val = (brightness & 0xF) << ARCXCNN_WLED_ISET_LSB_SHIFT;
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ret = i2c_smbus_write_byte_data(lp->client,
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ARCXCNN_WLED_ISET_LSB, val);
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if (ret < 0)
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return ret;
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/* remaining 8 bits of brightness go in MSB register */
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val = (brightness >> 4);
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return i2c_smbus_write_byte_data(lp->client,
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ARCXCNN_WLED_ISET_MSB, val);
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}
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static int arcxcnn_bl_update_status(struct backlight_device *bl)
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{
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struct arcxcnn *lp = bl_get_data(bl);
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u32 brightness = backlight_get_brightness(bl);
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int ret;
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ret = arcxcnn_set_brightness(lp, brightness);
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if (ret)
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return ret;
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/* set power-on/off/save modes */
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return arcxcnn_update_field(lp, ARCXCNN_CMD, ARCXCNN_CMD_STDBY,
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(bl->props.power == 0) ? 0 : ARCXCNN_CMD_STDBY);
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}
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static const struct backlight_ops arcxcnn_bl_ops = {
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.options = BL_CORE_SUSPENDRESUME,
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.update_status = arcxcnn_bl_update_status,
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};
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static int arcxcnn_backlight_register(struct arcxcnn *lp)
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{
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struct backlight_properties *props;
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const char *name = lp->pdata->name ? : "arctic_bl";
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props = devm_kzalloc(lp->dev, sizeof(*props), GFP_KERNEL);
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if (!props)
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return -ENOMEM;
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props->type = BACKLIGHT_PLATFORM;
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props->max_brightness = MAX_BRIGHTNESS;
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if (lp->pdata->initial_brightness > props->max_brightness)
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lp->pdata->initial_brightness = props->max_brightness;
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props->brightness = lp->pdata->initial_brightness;
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lp->bl = devm_backlight_device_register(lp->dev, name, lp->dev, lp,
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&arcxcnn_bl_ops, props);
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return PTR_ERR_OR_ZERO(lp->bl);
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}
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static void arcxcnn_parse_dt(struct arcxcnn *lp)
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{
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struct device *dev = lp->dev;
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struct device_node *node = dev->of_node;
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u32 prog_val, num_entry, entry, sources[ARCXCNN_LEDEN_BITS];
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int ret;
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/* device tree entry isn't required, defaults are OK */
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if (!node)
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return;
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ret = of_property_read_string(node, "label", &lp->pdata->name);
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if (ret < 0)
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lp->pdata->name = NULL;
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ret = of_property_read_u32(node, "default-brightness", &prog_val);
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if (ret == 0)
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lp->pdata->initial_brightness = prog_val;
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ret = of_property_read_u32(node, "arc,led-config-0", &prog_val);
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if (ret == 0)
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lp->pdata->led_config_0 = (u8)prog_val;
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ret = of_property_read_u32(node, "arc,led-config-1", &prog_val);
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if (ret == 0)
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lp->pdata->led_config_1 = (u8)prog_val;
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ret = of_property_read_u32(node, "arc,dim-freq", &prog_val);
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if (ret == 0)
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lp->pdata->dim_freq = (u8)prog_val;
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ret = of_property_read_u32(node, "arc,comp-config", &prog_val);
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if (ret == 0)
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lp->pdata->comp_config = (u8)prog_val;
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ret = of_property_read_u32(node, "arc,filter-config", &prog_val);
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if (ret == 0)
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lp->pdata->filter_config = (u8)prog_val;
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ret = of_property_read_u32(node, "arc,trim-config", &prog_val);
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if (ret == 0)
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lp->pdata->trim_config = (u8)prog_val;
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ret = of_property_count_u32_elems(node, "led-sources");
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if (ret < 0) {
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lp->pdata->leden = ARCXCNN_LEDEN_MASK; /* all on is default */
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} else {
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num_entry = ret;
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if (num_entry > ARCXCNN_LEDEN_BITS)
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num_entry = ARCXCNN_LEDEN_BITS;
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ret = of_property_read_u32_array(node, "led-sources", sources,
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num_entry);
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if (ret < 0) {
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dev_err(dev, "led-sources node is invalid.\n");
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return;
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}
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lp->pdata->leden = 0;
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/* for each enable in source, set bit in led enable */
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for (entry = 0; entry < num_entry; entry++) {
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u8 onbit = 1 << sources[entry];
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lp->pdata->leden |= onbit;
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}
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}
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}
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static int arcxcnn_probe(struct i2c_client *cl)
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{
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struct arcxcnn *lp;
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int ret;
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if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
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return -EIO;
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lp = devm_kzalloc(&cl->dev, sizeof(*lp), GFP_KERNEL);
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if (!lp)
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return -ENOMEM;
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lp->client = cl;
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lp->dev = &cl->dev;
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lp->pdata = dev_get_platdata(&cl->dev);
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/* reset the device */
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ret = i2c_smbus_write_byte_data(lp->client,
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ARCXCNN_CMD, ARCXCNN_CMD_RESET);
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if (ret)
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goto probe_err;
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if (!lp->pdata) {
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lp->pdata = devm_kzalloc(lp->dev,
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sizeof(*lp->pdata), GFP_KERNEL);
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if (!lp->pdata)
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return -ENOMEM;
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/* Setup defaults based on power-on defaults */
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lp->pdata->name = NULL;
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lp->pdata->initial_brightness = INIT_BRIGHT;
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lp->pdata->leden = ARCXCNN_LEDEN_MASK;
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lp->pdata->led_config_0 = i2c_smbus_read_byte_data(
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lp->client, ARCXCNN_FADECTRL);
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lp->pdata->led_config_1 = i2c_smbus_read_byte_data(
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lp->client, ARCXCNN_ILED_CONFIG);
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/* insure dim mode is not default pwm */
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lp->pdata->led_config_1 |= ARCXCNN_ILED_DIM_INT;
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lp->pdata->dim_freq = i2c_smbus_read_byte_data(
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lp->client, ARCXCNN_DIMFREQ);
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lp->pdata->comp_config = i2c_smbus_read_byte_data(
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lp->client, ARCXCNN_COMP_CONFIG);
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lp->pdata->filter_config = i2c_smbus_read_byte_data(
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lp->client, ARCXCNN_FILT_CONFIG);
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lp->pdata->trim_config = i2c_smbus_read_byte_data(
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lp->client, ARCXCNN_IMAXTUNE);
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if (IS_ENABLED(CONFIG_OF))
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arcxcnn_parse_dt(lp);
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}
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i2c_set_clientdata(cl, lp);
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/* constrain settings to what is possible */
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if (lp->pdata->initial_brightness > MAX_BRIGHTNESS)
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lp->pdata->initial_brightness = MAX_BRIGHTNESS;
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/* set initial brightness */
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ret = arcxcnn_set_brightness(lp, lp->pdata->initial_brightness);
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if (ret)
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goto probe_err;
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/* set other register values directly */
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ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_FADECTRL,
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lp->pdata->led_config_0);
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if (ret)
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goto probe_err;
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ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_ILED_CONFIG,
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lp->pdata->led_config_1);
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if (ret)
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goto probe_err;
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ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_DIMFREQ,
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lp->pdata->dim_freq);
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if (ret)
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goto probe_err;
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ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_COMP_CONFIG,
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lp->pdata->comp_config);
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if (ret)
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goto probe_err;
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ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_FILT_CONFIG,
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lp->pdata->filter_config);
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if (ret)
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goto probe_err;
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ret = i2c_smbus_write_byte_data(lp->client, ARCXCNN_IMAXTUNE,
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lp->pdata->trim_config);
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if (ret)
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goto probe_err;
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/* set initial LED Enables */
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arcxcnn_update_field(lp, ARCXCNN_LEDEN,
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ARCXCNN_LEDEN_MASK, lp->pdata->leden);
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ret = arcxcnn_backlight_register(lp);
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if (ret)
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goto probe_register_err;
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|
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 void 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);
|
||
|
|
}
|
||
|
|
|
||
|
|
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_new = 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");
|