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229 lines
5.2 KiB
229 lines
5.2 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Driver for BCM6358 memory-mapped LEDs, based on leds-syscon.c |
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* |
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* Copyright 2015 Álvaro Fernández Rojas <[email protected]> |
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*/ |
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#include <linux/delay.h> |
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#include <linux/io.h> |
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#include <linux/leds.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/platform_device.h> |
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#include <linux/spinlock.h> |
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#define BCM6358_REG_MODE 0x0 |
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#define BCM6358_REG_CTRL 0x4 |
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#define BCM6358_SLED_CLKDIV_MASK 3 |
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#define BCM6358_SLED_CLKDIV_1 0 |
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#define BCM6358_SLED_CLKDIV_2 1 |
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#define BCM6358_SLED_CLKDIV_4 2 |
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#define BCM6358_SLED_CLKDIV_8 3 |
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#define BCM6358_SLED_POLARITY BIT(2) |
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#define BCM6358_SLED_BUSY BIT(3) |
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#define BCM6358_SLED_MAX_COUNT 32 |
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#define BCM6358_SLED_WAIT 100 |
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/** |
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* struct bcm6358_led - state container for bcm6358 based LEDs |
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* @cdev: LED class device for this LED |
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* @mem: memory resource |
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* @lock: memory lock |
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* @pin: LED pin number |
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* @active_low: LED is active low |
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*/ |
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struct bcm6358_led { |
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struct led_classdev cdev; |
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void __iomem *mem; |
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spinlock_t *lock; |
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unsigned long pin; |
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bool active_low; |
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}; |
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static void bcm6358_led_write(void __iomem *reg, unsigned long data) |
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{ |
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#ifdef CONFIG_CPU_BIG_ENDIAN |
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iowrite32be(data, reg); |
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#else |
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writel(data, reg); |
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#endif |
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} |
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static unsigned long bcm6358_led_read(void __iomem *reg) |
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{ |
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#ifdef CONFIG_CPU_BIG_ENDIAN |
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return ioread32be(reg); |
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#else |
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return readl(reg); |
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#endif |
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} |
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static unsigned long bcm6358_led_busy(void __iomem *mem) |
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{ |
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unsigned long val; |
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while ((val = bcm6358_led_read(mem + BCM6358_REG_CTRL)) & |
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BCM6358_SLED_BUSY) |
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udelay(BCM6358_SLED_WAIT); |
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return val; |
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} |
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static void bcm6358_led_set(struct led_classdev *led_cdev, |
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enum led_brightness value) |
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{ |
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struct bcm6358_led *led = |
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container_of(led_cdev, struct bcm6358_led, cdev); |
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unsigned long flags, val; |
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spin_lock_irqsave(led->lock, flags); |
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bcm6358_led_busy(led->mem); |
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val = bcm6358_led_read(led->mem + BCM6358_REG_MODE); |
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if ((led->active_low && value == LED_OFF) || |
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(!led->active_low && value != LED_OFF)) |
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val |= BIT(led->pin); |
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else |
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val &= ~(BIT(led->pin)); |
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bcm6358_led_write(led->mem + BCM6358_REG_MODE, val); |
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spin_unlock_irqrestore(led->lock, flags); |
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} |
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static int bcm6358_led(struct device *dev, struct device_node *nc, u32 reg, |
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void __iomem *mem, spinlock_t *lock) |
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{ |
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struct led_init_data init_data = {}; |
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struct bcm6358_led *led; |
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const char *state; |
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int rc; |
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led = devm_kzalloc(dev, sizeof(*led), GFP_KERNEL); |
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if (!led) |
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return -ENOMEM; |
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led->pin = reg; |
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led->mem = mem; |
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led->lock = lock; |
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if (of_property_read_bool(nc, "active-low")) |
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led->active_low = true; |
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if (!of_property_read_string(nc, "default-state", &state)) { |
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if (!strcmp(state, "on")) { |
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led->cdev.brightness = LED_FULL; |
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} else if (!strcmp(state, "keep")) { |
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unsigned long val; |
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val = bcm6358_led_read(led->mem + BCM6358_REG_MODE); |
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val &= BIT(led->pin); |
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if ((led->active_low && !val) || |
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(!led->active_low && val)) |
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led->cdev.brightness = LED_FULL; |
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else |
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led->cdev.brightness = LED_OFF; |
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} else { |
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led->cdev.brightness = LED_OFF; |
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} |
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} else { |
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led->cdev.brightness = LED_OFF; |
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} |
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bcm6358_led_set(&led->cdev, led->cdev.brightness); |
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led->cdev.brightness_set = bcm6358_led_set; |
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init_data.fwnode = of_fwnode_handle(nc); |
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rc = devm_led_classdev_register_ext(dev, &led->cdev, &init_data); |
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if (rc < 0) |
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return rc; |
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dev_dbg(dev, "registered LED %s\n", led->cdev.name); |
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return 0; |
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} |
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static int bcm6358_leds_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct device_node *np = dev_of_node(&pdev->dev); |
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struct device_node *child; |
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void __iomem *mem; |
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spinlock_t *lock; /* memory lock */ |
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unsigned long val; |
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u32 clk_div; |
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mem = devm_platform_ioremap_resource(pdev, 0); |
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if (IS_ERR(mem)) |
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return PTR_ERR(mem); |
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lock = devm_kzalloc(dev, sizeof(*lock), GFP_KERNEL); |
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if (!lock) |
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return -ENOMEM; |
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spin_lock_init(lock); |
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val = bcm6358_led_busy(mem); |
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val &= ~(BCM6358_SLED_POLARITY | BCM6358_SLED_CLKDIV_MASK); |
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if (of_property_read_bool(np, "brcm,clk-dat-low")) |
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val |= BCM6358_SLED_POLARITY; |
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of_property_read_u32(np, "brcm,clk-div", &clk_div); |
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switch (clk_div) { |
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case 8: |
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val |= BCM6358_SLED_CLKDIV_8; |
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break; |
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case 4: |
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val |= BCM6358_SLED_CLKDIV_4; |
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break; |
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case 2: |
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val |= BCM6358_SLED_CLKDIV_2; |
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break; |
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default: |
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val |= BCM6358_SLED_CLKDIV_1; |
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break; |
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} |
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bcm6358_led_write(mem + BCM6358_REG_CTRL, val); |
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for_each_available_child_of_node(np, child) { |
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int rc; |
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u32 reg; |
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if (of_property_read_u32(child, "reg", ®)) |
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continue; |
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if (reg >= BCM6358_SLED_MAX_COUNT) { |
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dev_err(dev, "invalid LED (%u >= %d)\n", reg, |
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BCM6358_SLED_MAX_COUNT); |
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continue; |
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} |
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rc = bcm6358_led(dev, child, reg, mem, lock); |
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if (rc < 0) { |
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of_node_put(child); |
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return rc; |
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} |
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} |
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return 0; |
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} |
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static const struct of_device_id bcm6358_leds_of_match[] = { |
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{ .compatible = "brcm,bcm6358-leds", }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(of, bcm6358_leds_of_match); |
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static struct platform_driver bcm6358_leds_driver = { |
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.probe = bcm6358_leds_probe, |
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.driver = { |
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.name = "leds-bcm6358", |
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.of_match_table = bcm6358_leds_of_match, |
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}, |
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}; |
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module_platform_driver(bcm6358_leds_driver); |
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MODULE_AUTHOR("Álvaro Fernández Rojas <[email protected]>"); |
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MODULE_DESCRIPTION("LED driver for BCM6358 controllers"); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_ALIAS("platform:leds-bcm6358");
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