diff options
Diffstat (limited to 'drivers/leds/blink/leds-bcm63138.c')
| -rw-r--r-- | drivers/leds/blink/leds-bcm63138.c | 307 |
1 files changed, 307 insertions, 0 deletions
diff --git a/drivers/leds/blink/leds-bcm63138.c b/drivers/leds/blink/leds-bcm63138.c new file mode 100644 index 000000000..2cf2761e4 --- /dev/null +++ b/drivers/leds/blink/leds-bcm63138.c @@ -0,0 +1,307 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Rafał Miłecki <rafal@milecki.pl> + */ +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/pinctrl/consumer.h> +#include <linux/platform_device.h> +#include <linux/spinlock.h> + +#define BCM63138_MAX_LEDS 32 +#define BCM63138_MAX_BRIGHTNESS 9 + +#define BCM63138_LED_BITS 4 /* how many bits control a single LED */ +#define BCM63138_LED_MASK ((1 << BCM63138_LED_BITS) - 1) /* 0xf */ +#define BCM63138_LEDS_PER_REG (32 / BCM63138_LED_BITS) /* 8 */ + +#define BCM63138_GLB_CTRL 0x00 +#define BCM63138_GLB_CTRL_SERIAL_LED_DATA_PPOL 0x00000002 +#define BCM63138_GLB_CTRL_SERIAL_LED_EN_POL 0x00000008 +#define BCM63138_MASK 0x04 +#define BCM63138_HW_LED_EN 0x08 +#define BCM63138_SERIAL_LED_SHIFT_SEL 0x0c +#define BCM63138_FLASH_RATE_CTRL1 0x10 +#define BCM63138_FLASH_RATE_CTRL2 0x14 +#define BCM63138_FLASH_RATE_CTRL3 0x18 +#define BCM63138_FLASH_RATE_CTRL4 0x1c +#define BCM63138_BRIGHT_CTRL1 0x20 +#define BCM63138_BRIGHT_CTRL2 0x24 +#define BCM63138_BRIGHT_CTRL3 0x28 +#define BCM63138_BRIGHT_CTRL4 0x2c +#define BCM63138_POWER_LED_CFG 0x30 +#define BCM63138_HW_POLARITY 0xb4 +#define BCM63138_SW_DATA 0xb8 +#define BCM63138_SW_POLARITY 0xbc +#define BCM63138_PARALLEL_LED_POLARITY 0xc0 +#define BCM63138_SERIAL_LED_POLARITY 0xc4 +#define BCM63138_HW_LED_STATUS 0xc8 +#define BCM63138_FLASH_CTRL_STATUS 0xcc +#define BCM63138_FLASH_BRT_CTRL 0xd0 +#define BCM63138_FLASH_P_LED_OUT_STATUS 0xd4 +#define BCM63138_FLASH_S_LED_OUT_STATUS 0xd8 + +struct bcm63138_leds { + struct device *dev; + void __iomem *base; + spinlock_t lock; +}; + +struct bcm63138_led { + struct bcm63138_leds *leds; + struct led_classdev cdev; + u32 pin; + bool active_low; +}; + +/* + * I/O access + */ + +static void bcm63138_leds_write(struct bcm63138_leds *leds, unsigned int reg, + u32 data) +{ + writel(data, leds->base + reg); +} + +static unsigned long bcm63138_leds_read(struct bcm63138_leds *leds, + unsigned int reg) +{ + return readl(leds->base + reg); +} + +static void bcm63138_leds_update_bits(struct bcm63138_leds *leds, + unsigned int reg, u32 mask, u32 val) +{ + WARN_ON(val & ~mask); + + bcm63138_leds_write(leds, reg, (bcm63138_leds_read(leds, reg) & ~mask) | (val & mask)); +} + +/* + * Helpers + */ + +static void bcm63138_leds_set_flash_rate(struct bcm63138_leds *leds, + struct bcm63138_led *led, + u8 value) +{ + int reg_offset = (led->pin >> fls((BCM63138_LEDS_PER_REG - 1))) * 4; + int shift = (led->pin & (BCM63138_LEDS_PER_REG - 1)) * BCM63138_LED_BITS; + + bcm63138_leds_update_bits(leds, BCM63138_FLASH_RATE_CTRL1 + reg_offset, + BCM63138_LED_MASK << shift, value << shift); +} + +static void bcm63138_leds_set_bright(struct bcm63138_leds *leds, + struct bcm63138_led *led, + u8 value) +{ + int reg_offset = (led->pin >> fls((BCM63138_LEDS_PER_REG - 1))) * 4; + int shift = (led->pin & (BCM63138_LEDS_PER_REG - 1)) * BCM63138_LED_BITS; + + bcm63138_leds_update_bits(leds, BCM63138_BRIGHT_CTRL1 + reg_offset, + BCM63138_LED_MASK << shift, value << shift); +} + +static void bcm63138_leds_enable_led(struct bcm63138_leds *leds, + struct bcm63138_led *led, + enum led_brightness value) +{ + u32 bit = BIT(led->pin); + + bcm63138_leds_update_bits(leds, BCM63138_SW_DATA, bit, value ? bit : 0); +} + +/* + * API callbacks + */ + +static void bcm63138_leds_brightness_set(struct led_classdev *led_cdev, + enum led_brightness value) +{ + struct bcm63138_led *led = container_of(led_cdev, struct bcm63138_led, cdev); + struct bcm63138_leds *leds = led->leds; + unsigned long flags; + + spin_lock_irqsave(&leds->lock, flags); + + bcm63138_leds_enable_led(leds, led, value); + if (!value) + bcm63138_leds_set_flash_rate(leds, led, 0); + else + bcm63138_leds_set_bright(leds, led, value); + + spin_unlock_irqrestore(&leds->lock, flags); +} + +static int bcm63138_leds_blink_set(struct led_classdev *led_cdev, + unsigned long *delay_on, + unsigned long *delay_off) +{ + struct bcm63138_led *led = container_of(led_cdev, struct bcm63138_led, cdev); + struct bcm63138_leds *leds = led->leds; + unsigned long flags; + u8 value; + + if (!*delay_on && !*delay_off) { + *delay_on = 640; + *delay_off = 640; + } + + if (*delay_on != *delay_off) { + dev_dbg(led_cdev->dev, "Blinking at unequal delays is not supported\n"); + return -EINVAL; + } + + switch (*delay_on) { + case 1152 ... 1408: /* 1280 ms ± 10% */ + value = 0x7; + break; + case 576 ... 704: /* 640 ms ± 10% */ + value = 0x6; + break; + case 288 ... 352: /* 320 ms ± 10% */ + value = 0x5; + break; + case 126 ... 154: /* 140 ms ± 10% */ + value = 0x4; + break; + case 59 ... 72: /* 65 ms ± 10% */ + value = 0x3; + break; + default: + dev_dbg(led_cdev->dev, "Blinking delay value %lu is unsupported\n", + *delay_on); + return -EINVAL; + } + + spin_lock_irqsave(&leds->lock, flags); + + bcm63138_leds_enable_led(leds, led, BCM63138_MAX_BRIGHTNESS); + bcm63138_leds_set_flash_rate(leds, led, value); + + spin_unlock_irqrestore(&leds->lock, flags); + + return 0; +} + +/* + * LED driver + */ + +static void bcm63138_leds_create_led(struct bcm63138_leds *leds, + struct device_node *np) +{ + struct led_init_data init_data = { + .fwnode = of_fwnode_handle(np), + }; + struct device *dev = leds->dev; + struct bcm63138_led *led; + struct pinctrl *pinctrl; + u32 bit; + int err; + + led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL); + if (!led) { + dev_err(dev, "Failed to alloc LED\n"); + return; + } + + led->leds = leds; + + if (of_property_read_u32(np, "reg", &led->pin)) { + dev_err(dev, "Missing \"reg\" property in %pOF\n", np); + goto err_free; + } + + if (led->pin >= BCM63138_MAX_LEDS) { + dev_err(dev, "Invalid \"reg\" value %d\n", led->pin); + goto err_free; + } + + led->active_low = of_property_read_bool(np, "active-low"); + + led->cdev.max_brightness = BCM63138_MAX_BRIGHTNESS; + led->cdev.brightness_set = bcm63138_leds_brightness_set; + led->cdev.blink_set = bcm63138_leds_blink_set; + + err = devm_led_classdev_register_ext(dev, &led->cdev, &init_data); + if (err) { + dev_err(dev, "Failed to register LED %pOF: %d\n", np, err); + goto err_free; + } + + pinctrl = devm_pinctrl_get_select_default(led->cdev.dev); + if (IS_ERR(pinctrl) && PTR_ERR(pinctrl) != -ENODEV) { + dev_warn(led->cdev.dev, "Failed to select %pOF pinctrl: %ld\n", + np, PTR_ERR(pinctrl)); + } + + bit = BIT(led->pin); + bcm63138_leds_update_bits(leds, BCM63138_PARALLEL_LED_POLARITY, bit, + led->active_low ? 0 : bit); + bcm63138_leds_update_bits(leds, BCM63138_HW_LED_EN, bit, 0); + bcm63138_leds_set_flash_rate(leds, led, 0); + bcm63138_leds_enable_led(leds, led, led->cdev.brightness); + + return; + +err_free: + devm_kfree(dev, led); +} + +static int bcm63138_leds_probe(struct platform_device *pdev) +{ + struct device_node *np = dev_of_node(&pdev->dev); + struct device *dev = &pdev->dev; + struct bcm63138_leds *leds; + struct device_node *child; + + leds = devm_kzalloc(dev, sizeof(*leds), GFP_KERNEL); + if (!leds) + return -ENOMEM; + + leds->dev = dev; + + leds->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(leds->base)) + return PTR_ERR(leds->base); + + spin_lock_init(&leds->lock); + + bcm63138_leds_write(leds, BCM63138_GLB_CTRL, + BCM63138_GLB_CTRL_SERIAL_LED_DATA_PPOL | + BCM63138_GLB_CTRL_SERIAL_LED_EN_POL); + bcm63138_leds_write(leds, BCM63138_HW_LED_EN, 0); + bcm63138_leds_write(leds, BCM63138_SERIAL_LED_POLARITY, 0); + bcm63138_leds_write(leds, BCM63138_PARALLEL_LED_POLARITY, 0); + + for_each_available_child_of_node(np, child) { + bcm63138_leds_create_led(leds, child); + } + + return 0; +} + +static const struct of_device_id bcm63138_leds_of_match_table[] = { + { .compatible = "brcm,bcm63138-leds", }, + { }, +}; + +static struct platform_driver bcm63138_leds_driver = { + .probe = bcm63138_leds_probe, + .driver = { + .name = "leds-bcm63xxx", + .of_match_table = bcm63138_leds_of_match_table, + }, +}; + +module_platform_driver(bcm63138_leds_driver); + +MODULE_AUTHOR("Rafał Miłecki"); +MODULE_LICENSE("GPL"); +MODULE_DEVICE_TABLE(of, bcm63138_leds_of_match_table); |