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freifunkist-firmware/target/linux/ramips/patches-3.18/0019-MIPS-ralink-add-pseudo...

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From 9de00286e20a5f5edc419698373010f1cb6ff0ce Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Sun, 27 Jul 2014 09:25:02 +0100
Subject: [PATCH 19/57] MIPS: ralink: add pseudo pwm led trigger based on
timer0
Signed-off-by: John Crispin <blogic@openwrt.org>
---
arch/mips/ralink/timer.c | 213 ++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 197 insertions(+), 16 deletions(-)
--- a/arch/mips/ralink/timer.c
+++ b/arch/mips/ralink/timer.c
@@ -12,6 +12,8 @@
#include <linux/timer.h>
#include <linux/of_gpio.h>
#include <linux/clk.h>
+#include <linux/leds.h>
+#include <linux/slab.h>
#include <asm/mach-ralink/ralink_regs.h>
@@ -23,16 +25,34 @@
#define TMR0CTL_ENABLE BIT(7)
#define TMR0CTL_MODE_PERIODIC BIT(4)
-#define TMR0CTL_PRESCALER 1
+#define TMR0CTL_PRESCALER 2
#define TMR0CTL_PRESCALE_VAL (0xf - TMR0CTL_PRESCALER)
#define TMR0CTL_PRESCALE_DIV (65536 / BIT(TMR0CTL_PRESCALER))
+struct rt_timer_gpio {
+ struct list_head list;
+ struct led_classdev *led;
+};
+
struct rt_timer {
- struct device *dev;
- void __iomem *membase;
- int irq;
- unsigned long timer_freq;
- unsigned long timer_div;
+ struct device *dev;
+ void __iomem *membase;
+ int irq;
+
+ unsigned long timer_freq;
+ unsigned long timer_div;
+
+ struct list_head gpios;
+ struct led_trigger led_trigger;
+ unsigned int duty_cycle;
+ unsigned int duty;
+
+ unsigned int fade;
+ unsigned int fade_min;
+ unsigned int fade_max;
+ unsigned int fade_speed;
+ unsigned int fade_dir;
+ unsigned int fade_count;
};
static inline void rt_timer_w32(struct rt_timer *rt, u8 reg, u32 val)
@@ -48,8 +68,37 @@ static inline u32 rt_timer_r32(struct rt
static irqreturn_t rt_timer_irq(int irq, void *_rt)
{
struct rt_timer *rt = (struct rt_timer *) _rt;
+ struct rt_timer_gpio *gpio;
+ unsigned int val;
- rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
+ if (rt->fade && (rt->fade_count++ > rt->fade_speed)) {
+ rt->fade_count = 0;
+ if (rt->duty_cycle <= rt->fade_min)
+ rt->fade_dir = 1;
+ else if (rt->duty_cycle >= rt->fade_max)
+ rt->fade_dir = 0;
+
+ if (rt->fade_dir)
+ rt->duty_cycle += 1;
+ else
+ rt->duty_cycle -= 1;
+
+ }
+
+ val = rt->timer_freq / rt->timer_div;
+ if (rt->duty)
+ val *= rt->duty_cycle;
+ else
+ val *= (100 - rt->duty_cycle);
+ val /= 100;
+
+ if (!list_empty(&rt->gpios))
+ list_for_each_entry(gpio, &rt->gpios, list)
+ led_set_brightness(gpio->led, !!rt->duty);
+
+ rt->duty = !rt->duty;
+
+ rt_timer_w32(rt, TIMER_REG_TMR0LOAD, val + 1);
rt_timer_w32(rt, TIMER_REG_TMRSTAT, TMRSTAT_TMR0INT);
return IRQ_HANDLED;
@@ -58,8 +107,8 @@ static irqreturn_t rt_timer_irq(int irq,
static int rt_timer_request(struct rt_timer *rt)
{
- int err = request_irq(rt->irq, rt_timer_irq, 0,
- dev_name(rt->dev), rt);
+ int err = devm_request_irq(rt->dev, rt->irq, rt_timer_irq,
+ 0, dev_name(rt->dev), rt);
if (err) {
dev_err(rt->dev, "failed to request irq\n");
} else {
@@ -81,8 +130,6 @@ static int rt_timer_config(struct rt_tim
else
rt->timer_div = divisor;
- rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
-
return 0;
}
@@ -108,11 +155,128 @@ static void rt_timer_disable(struct rt_t
rt_timer_w32(rt, TIMER_REG_TMR0CTL, t);
}
+static ssize_t led_fade_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
+
+ return sprintf(buf, "speed: %d, min: %d, max: %d\n", rt->fade_speed, rt->fade_min, rt->fade_max);
+}
+
+static ssize_t led_fade_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
+ unsigned int speed = 0, min = 0, max = 0;
+ ssize_t ret = -EINVAL;
+
+ ret = sscanf(buf, "%u %u %u", &speed, &min, &max);
+
+ if (ret == 3) {
+ rt->fade_speed = speed;
+ rt->fade_min = min;
+ rt->fade_max = max;
+ rt->fade = 1;
+ } else {
+ rt->fade = 0;
+ }
+
+ return size;
+}
+
+static DEVICE_ATTR(fade, 0644, led_fade_show, led_fade_store);
+
+static ssize_t led_duty_cycle_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
+
+ return sprintf(buf, "%u\n", rt->duty_cycle);
+}
+
+static ssize_t led_duty_cycle_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+ struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
+ unsigned long state;
+ ssize_t ret = -EINVAL;
+
+ ret = kstrtoul(buf, 10, &state);
+ if (ret)
+ return ret;
+
+ if (state <= 100)
+ rt->duty_cycle = state;
+ else
+ rt->duty_cycle = 100;
+
+ rt->fade = 0;
+
+ return size;
+}
+
+static DEVICE_ATTR(duty_cycle, 0644, led_duty_cycle_show, led_duty_cycle_store);
+
+static void rt_timer_trig_activate(struct led_classdev *led_cdev)
+{
+ struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
+ struct rt_timer_gpio *gpio_data;
+ int rc;
+
+ led_cdev->trigger_data = NULL;
+ gpio_data = kzalloc(sizeof(*gpio_data), GFP_KERNEL);
+ if (!gpio_data)
+ return;
+
+ rc = device_create_file(led_cdev->dev, &dev_attr_duty_cycle);
+ if (rc)
+ goto err_gpio;
+ rc = device_create_file(led_cdev->dev, &dev_attr_fade);
+ if (rc)
+ goto err_out_duty_cycle;
+
+ led_cdev->activated = true;
+ led_cdev->trigger_data = gpio_data;
+ gpio_data->led = led_cdev;
+ list_add(&gpio_data->list, &rt->gpios);
+ led_cdev->trigger_data = gpio_data;
+ rt_timer_enable(rt);
+ return;
+
+err_out_duty_cycle:
+ device_remove_file(led_cdev->dev, &dev_attr_duty_cycle);
+
+err_gpio:
+ kfree(gpio_data);
+}
+
+static void rt_timer_trig_deactivate(struct led_classdev *led_cdev)
+{
+ struct rt_timer *rt = container_of(led_cdev->trigger, struct rt_timer, led_trigger);
+ struct rt_timer_gpio *gpio_data = (struct rt_timer_gpio*) led_cdev->trigger_data;
+
+ if (led_cdev->activated) {
+ device_remove_file(led_cdev->dev, &dev_attr_duty_cycle);
+ device_remove_file(led_cdev->dev, &dev_attr_fade);
+ led_cdev->activated = false;
+ }
+
+ list_del(&gpio_data->list);
+ rt_timer_disable(rt);
+ led_set_brightness(led_cdev, LED_OFF);
+}
+
static int rt_timer_probe(struct platform_device *pdev)
{
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ const __be32 *divisor;
struct rt_timer *rt;
struct clk *clk;
+ int ret;
rt = devm_kzalloc(&pdev->dev, sizeof(*rt), GFP_KERNEL);
if (!rt) {
@@ -140,12 +304,29 @@ static int rt_timer_probe(struct platfor
if (!rt->timer_freq)
return -EINVAL;
+ rt->duty_cycle = 100;
rt->dev = &pdev->dev;
platform_set_drvdata(pdev, rt);
- rt_timer_request(rt);
- rt_timer_config(rt, 2);
- rt_timer_enable(rt);
+ ret = rt_timer_request(rt);
+ if (ret)
+ return ret;
+
+ divisor = of_get_property(pdev->dev.of_node, "ralink,divisor", NULL);
+ if (divisor)
+ rt_timer_config(rt, be32_to_cpu(*divisor));
+ else
+ rt_timer_config(rt, 200);
+
+ rt->led_trigger.name = "pwmtimer",
+ rt->led_trigger.activate = rt_timer_trig_activate,
+ rt->led_trigger.deactivate = rt_timer_trig_deactivate,
+
+ ret = led_trigger_register(&rt->led_trigger);
+ if (ret)
+ return ret;
+
+ INIT_LIST_HEAD(&rt->gpios);
dev_info(&pdev->dev, "maximum frequency is %luHz\n", rt->timer_freq);
@@ -156,6 +337,7 @@ static int rt_timer_remove(struct platfo
{
struct rt_timer *rt = platform_get_drvdata(pdev);
+ led_trigger_unregister(&rt->led_trigger);
rt_timer_disable(rt);
rt_timer_free(rt);
@@ -180,6 +362,6 @@ static struct platform_driver rt_timer_d
module_platform_driver(rt_timer_driver);
-MODULE_DESCRIPTION("Ralink RT2880 timer");
+MODULE_DESCRIPTION("Ralink RT2880 timer / pseudo pwm");
MODULE_AUTHOR("John Crispin <blogic@openwrt.org");
MODULE_LICENSE("GPL");