309 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl>4 */5#include <linux/delay.h>6#include <linux/io.h>7#include <linux/leds.h>8#include <linux/module.h>9#include <linux/of.h>10#include <linux/pinctrl/consumer.h>11#include <linux/platform_device.h>12#include <linux/spinlock.h>13 14#define BCM63138_MAX_LEDS 3215#define BCM63138_MAX_BRIGHTNESS 916 17#define BCM63138_LED_BITS 4 /* how many bits control a single LED */18#define BCM63138_LED_MASK ((1 << BCM63138_LED_BITS) - 1) /* 0xf */19#define BCM63138_LEDS_PER_REG (32 / BCM63138_LED_BITS) /* 8 */20 21#define BCM63138_GLB_CTRL 0x0022#define BCM63138_GLB_CTRL_SERIAL_LED_DATA_PPOL 0x0000000223#define BCM63138_GLB_CTRL_SERIAL_LED_EN_POL 0x0000000824#define BCM63138_MASK 0x0425#define BCM63138_HW_LED_EN 0x0826#define BCM63138_SERIAL_LED_SHIFT_SEL 0x0c27#define BCM63138_FLASH_RATE_CTRL1 0x1028#define BCM63138_FLASH_RATE_CTRL2 0x1429#define BCM63138_FLASH_RATE_CTRL3 0x1830#define BCM63138_FLASH_RATE_CTRL4 0x1c31#define BCM63138_BRIGHT_CTRL1 0x2032#define BCM63138_BRIGHT_CTRL2 0x2433#define BCM63138_BRIGHT_CTRL3 0x2834#define BCM63138_BRIGHT_CTRL4 0x2c35#define BCM63138_POWER_LED_CFG 0x3036#define BCM63138_HW_POLARITY 0xb437#define BCM63138_SW_DATA 0xb838#define BCM63138_SW_POLARITY 0xbc39#define BCM63138_PARALLEL_LED_POLARITY 0xc040#define BCM63138_SERIAL_LED_POLARITY 0xc441#define BCM63138_HW_LED_STATUS 0xc842#define BCM63138_FLASH_CTRL_STATUS 0xcc43#define BCM63138_FLASH_BRT_CTRL 0xd044#define BCM63138_FLASH_P_LED_OUT_STATUS 0xd445#define BCM63138_FLASH_S_LED_OUT_STATUS 0xd846 47struct bcm63138_leds {48 struct device *dev;49 void __iomem *base;50 spinlock_t lock;51};52 53struct bcm63138_led {54 struct bcm63138_leds *leds;55 struct led_classdev cdev;56 u32 pin;57 bool active_low;58};59 60/*61 * I/O access62 */63 64static void bcm63138_leds_write(struct bcm63138_leds *leds, unsigned int reg,65 u32 data)66{67 writel(data, leds->base + reg);68}69 70static unsigned long bcm63138_leds_read(struct bcm63138_leds *leds,71 unsigned int reg)72{73 return readl(leds->base + reg);74}75 76static void bcm63138_leds_update_bits(struct bcm63138_leds *leds,77 unsigned int reg, u32 mask, u32 val)78{79 WARN_ON(val & ~mask);80 81 bcm63138_leds_write(leds, reg, (bcm63138_leds_read(leds, reg) & ~mask) | (val & mask));82}83 84/*85 * Helpers86 */87 88static void bcm63138_leds_set_flash_rate(struct bcm63138_leds *leds,89 struct bcm63138_led *led,90 u8 value)91{92 int reg_offset = (led->pin >> fls((BCM63138_LEDS_PER_REG - 1))) * 4;93 int shift = (led->pin & (BCM63138_LEDS_PER_REG - 1)) * BCM63138_LED_BITS;94 95 bcm63138_leds_update_bits(leds, BCM63138_FLASH_RATE_CTRL1 + reg_offset,96 BCM63138_LED_MASK << shift, value << shift);97}98 99static void bcm63138_leds_set_bright(struct bcm63138_leds *leds,100 struct bcm63138_led *led,101 u8 value)102{103 int reg_offset = (led->pin >> fls((BCM63138_LEDS_PER_REG - 1))) * 4;104 int shift = (led->pin & (BCM63138_LEDS_PER_REG - 1)) * BCM63138_LED_BITS;105 106 bcm63138_leds_update_bits(leds, BCM63138_BRIGHT_CTRL1 + reg_offset,107 BCM63138_LED_MASK << shift, value << shift);108}109 110static void bcm63138_leds_enable_led(struct bcm63138_leds *leds,111 struct bcm63138_led *led,112 enum led_brightness value)113{114 u32 bit = BIT(led->pin);115 116 bcm63138_leds_update_bits(leds, BCM63138_SW_DATA, bit, value ? bit : 0);117}118 119/*120 * API callbacks121 */122 123static void bcm63138_leds_brightness_set(struct led_classdev *led_cdev,124 enum led_brightness value)125{126 struct bcm63138_led *led = container_of(led_cdev, struct bcm63138_led, cdev);127 struct bcm63138_leds *leds = led->leds;128 unsigned long flags;129 130 spin_lock_irqsave(&leds->lock, flags);131 132 bcm63138_leds_enable_led(leds, led, value);133 if (!value)134 bcm63138_leds_set_flash_rate(leds, led, 0);135 else136 bcm63138_leds_set_bright(leds, led, value);137 138 spin_unlock_irqrestore(&leds->lock, flags);139}140 141static int bcm63138_leds_blink_set(struct led_classdev *led_cdev,142 unsigned long *delay_on,143 unsigned long *delay_off)144{145 struct bcm63138_led *led = container_of(led_cdev, struct bcm63138_led, cdev);146 struct bcm63138_leds *leds = led->leds;147 unsigned long flags;148 u8 value;149 150 if (!*delay_on && !*delay_off) {151 *delay_on = 640;152 *delay_off = 640;153 }154 155 if (*delay_on != *delay_off) {156 dev_dbg(led_cdev->dev, "Blinking at unequal delays is not supported\n");157 return -EINVAL;158 }159 160 switch (*delay_on) {161 case 1152 ... 1408: /* 1280 ms ± 10% */162 value = 0x7;163 break;164 case 576 ... 704: /* 640 ms ± 10% */165 value = 0x6;166 break;167 case 288 ... 352: /* 320 ms ± 10% */168 value = 0x5;169 break;170 case 126 ... 154: /* 140 ms ± 10% */171 value = 0x4;172 break;173 case 59 ... 72: /* 65 ms ± 10% */174 value = 0x3;175 break;176 default:177 dev_dbg(led_cdev->dev, "Blinking delay value %lu is unsupported\n",178 *delay_on);179 return -EINVAL;180 }181 182 spin_lock_irqsave(&leds->lock, flags);183 184 bcm63138_leds_enable_led(leds, led, BCM63138_MAX_BRIGHTNESS);185 bcm63138_leds_set_flash_rate(leds, led, value);186 187 spin_unlock_irqrestore(&leds->lock, flags);188 189 return 0;190}191 192/*193 * LED driver194 */195 196static void bcm63138_leds_create_led(struct bcm63138_leds *leds,197 struct device_node *np)198{199 struct led_init_data init_data = {200 .fwnode = of_fwnode_handle(np),201 };202 struct device *dev = leds->dev;203 struct bcm63138_led *led;204 struct pinctrl *pinctrl;205 u32 bit;206 int err;207 208 led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL);209 if (!led) {210 dev_err(dev, "Failed to alloc LED\n");211 return;212 }213 214 led->leds = leds;215 216 if (of_property_read_u32(np, "reg", &led->pin)) {217 dev_err(dev, "Missing \"reg\" property in %pOF\n", np);218 goto err_free;219 }220 221 if (led->pin >= BCM63138_MAX_LEDS) {222 dev_err(dev, "Invalid \"reg\" value %d\n", led->pin);223 goto err_free;224 }225 226 led->active_low = of_property_read_bool(np, "active-low");227 228 led->cdev.max_brightness = BCM63138_MAX_BRIGHTNESS;229 led->cdev.brightness_set = bcm63138_leds_brightness_set;230 led->cdev.blink_set = bcm63138_leds_blink_set;231 232 err = devm_led_classdev_register_ext(dev, &led->cdev, &init_data);233 if (err) {234 dev_err(dev, "Failed to register LED %pOF: %d\n", np, err);235 goto err_free;236 }237 238 pinctrl = devm_pinctrl_get_select_default(led->cdev.dev);239 if (IS_ERR(pinctrl) && PTR_ERR(pinctrl) != -ENODEV) {240 dev_warn(led->cdev.dev, "Failed to select %pOF pinctrl: %ld\n",241 np, PTR_ERR(pinctrl));242 }243 244 bit = BIT(led->pin);245 bcm63138_leds_update_bits(leds, BCM63138_PARALLEL_LED_POLARITY, bit,246 led->active_low ? 0 : bit);247 bcm63138_leds_update_bits(leds, BCM63138_HW_LED_EN, bit, 0);248 bcm63138_leds_set_flash_rate(leds, led, 0);249 bcm63138_leds_enable_led(leds, led, led->cdev.brightness);250 251 return;252 253err_free:254 devm_kfree(dev, led);255}256 257static int bcm63138_leds_probe(struct platform_device *pdev)258{259 struct device_node *np = dev_of_node(&pdev->dev);260 struct device *dev = &pdev->dev;261 struct bcm63138_leds *leds;262 struct device_node *child;263 264 leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL);265 if (!leds)266 return -ENOMEM;267 268 leds->dev = dev;269 270 leds->base = devm_platform_ioremap_resource(pdev, 0);271 if (IS_ERR(leds->base))272 return PTR_ERR(leds->base);273 274 spin_lock_init(&leds->lock);275 276 bcm63138_leds_write(leds, BCM63138_GLB_CTRL,277 BCM63138_GLB_CTRL_SERIAL_LED_DATA_PPOL |278 BCM63138_GLB_CTRL_SERIAL_LED_EN_POL);279 bcm63138_leds_write(leds, BCM63138_HW_LED_EN, 0);280 bcm63138_leds_write(leds, BCM63138_SERIAL_LED_POLARITY, 0);281 bcm63138_leds_write(leds, BCM63138_PARALLEL_LED_POLARITY, 0);282 283 for_each_available_child_of_node(np, child) {284 bcm63138_leds_create_led(leds, child);285 }286 287 return 0;288}289 290static const struct of_device_id bcm63138_leds_of_match_table[] = {291 { .compatible = "brcm,bcm63138-leds", },292 { },293};294 295static struct platform_driver bcm63138_leds_driver = {296 .probe = bcm63138_leds_probe,297 .driver = {298 .name = "leds-bcm63xxx",299 .of_match_table = bcm63138_leds_of_match_table,300 },301};302 303module_platform_driver(bcm63138_leds_driver);304 305MODULE_AUTHOR("Rafał Miłecki");306MODULE_DESCRIPTION("Broadcom BCM63138 SoC LED driver");307MODULE_LICENSE("GPL");308MODULE_DEVICE_TABLE(of, bcm63138_leds_of_match_table);309