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linuxdebug/drivers/leds/blink/leds-bcm63138.c

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// 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);
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