[PATCH] MIPS: ralink: add support for periodic timer irq

[PATCH] MIPS: ralink: add support for periodic timer irq

[John Crispin]

Adds a driver for the periodic timer found on Ralink SoC.

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 arch/mips/ralink/Makefile |    2 +-
 arch/mips/ralink/timer.c  |  192 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 193 insertions(+), 1 deletion(-)
 create mode 100644 arch/mips/ralink/timer.c

diff --git a/arch/mips/ralink/Makefile b/arch/mips/ralink/Makefile
index 38cf1a8..e37e0ec 100644
--- a/arch/mips/ralink/Makefile
+++ b/arch/mips/ralink/Makefile
@@ -6,7 +6,7 @@
 # Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
 # Copyright (C) 2013 John Crispin <blogic@openwrt.org>
 
-obj-y := prom.o of.o reset.o clk.o irq.o
+obj-y := prom.o of.o reset.o clk.o irq.o timer.o
 
 obj-$(CONFIG_SOC_RT288X) += rt288x.o
 obj-$(CONFIG_SOC_RT305X) += rt305x.o
diff --git a/arch/mips/ralink/timer.c b/arch/mips/ralink/timer.c
new file mode 100644
index 0000000..0a6856c
--- /dev/null
+++ b/arch/mips/ralink/timer.c
@@ -0,0 +1,192 @@
+/*
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
+*/
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/timer.h>
+#include <linux/of_gpio.h>
+#include <linux/clk.h>
+
+#include <asm/mach-ralink/ralink_regs.h>
+
+#define TIMER_REG_TMRSTAT		0x00
+#define TIMER_REG_TMR0LOAD		0x10
+#define TIMER_REG_TMR0CTL		0x18
+
+#define TMRSTAT_TMR0INT			BIT(0)
+
+#define TMR0CTL_ENABLE			BIT(7)
+#define TMR0CTL_MODE_PERIODIC		BIT(4)
+#define TMR0CTL_PRESCALER		1
+#define TMR0CTL_PRESCALE_VAL		(0xf - TMR0CTL_PRESCALER)
+#define TMR0CTL_PRESCALE_DIV		(65536 / BIT(TMR0CTL_PRESCALER))
+
+struct rt_timer {
+	struct device	*dev;
+	void __iomem	*membase;
+	int		irq;
+	unsigned long	timer_freq;
+	unsigned long	timer_div;
+};
+
+static inline void rt_timer_w32(struct rt_timer *rt, u8 reg, u32 val)
+{
+	__raw_writel(val, rt->membase + reg);
+}
+
+static inline u32 rt_timer_r32(struct rt_timer *rt, u8 reg)
+{
+	return __raw_readl(rt->membase + reg);
+}
+
+static irqreturn_t rt_timer_irq(int irq, void *_rt)
+{
+	struct rt_timer *rt =  (struct rt_timer *) _rt;
+
+	rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
+	rt_timer_w32(rt, TIMER_REG_TMRSTAT, TMRSTAT_TMR0INT);
+
+	return IRQ_HANDLED;
+}
+
+
+static int rt_timer_request(struct rt_timer *rt)
+{
+	int err = request_irq(rt->irq, rt_timer_irq, IRQF_DISABLED,
+						dev_name(rt->dev), rt);
+	if (err) {
+		dev_err(rt->dev, "failed to request irq\n");
+	} else {
+		u32 t = TMR0CTL_MODE_PERIODIC | TMR0CTL_PRESCALE_VAL;
+		rt_timer_w32(rt, TIMER_REG_TMR0CTL, t);
+	}
+	return err;
+}
+
+static void rt_timer_free(struct rt_timer *rt)
+{
+	free_irq(rt->irq, rt);
+}
+
+static int rt_timer_config(struct rt_timer *rt, unsigned long divisor)
+{
+	if (rt->timer_freq < divisor)
+		rt->timer_div = rt->timer_freq;
+	else
+		rt->timer_div = divisor;
+
+	rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
+
+	return 0;
+}
+
+static int rt_timer_enable(struct rt_timer *rt)
+{
+	u32 t;
+
+	rt_timer_w32(rt, TIMER_REG_TMR0LOAD, rt->timer_freq / rt->timer_div);
+
+	t = rt_timer_r32(rt, TIMER_REG_TMR0CTL);
+	t |= TMR0CTL_ENABLE;
+	rt_timer_w32(rt, TIMER_REG_TMR0CTL, t);
+
+	return 0;
+}
+
+static void rt_timer_disable(struct rt_timer *rt)
+{
+	u32 t;
+
+	t = rt_timer_r32(rt, TIMER_REG_TMR0CTL);
+	t &= ~TMR0CTL_ENABLE;
+	rt_timer_w32(rt, TIMER_REG_TMR0CTL, t);
+}
+
+static int rt_timer_probe(struct platform_device *pdev)
+{
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	struct rt_timer *rt;
+	struct clk *clk;
+
+	if (!res) {
+		dev_err(&pdev->dev, "no memory resource found\n");
+		return -EINVAL;
+	}
+
+	rt = devm_kzalloc(&pdev->dev, sizeof(*rt), GFP_KERNEL);
+	if (!rt) {
+		dev_err(&pdev->dev, "failed to allocate memory\n");
+		return -ENOMEM;
+	}
+
+	rt->irq = platform_get_irq(pdev, 0);
+	if (!rt->irq) {
+		dev_err(&pdev->dev, "failed to load irq\n");
+		return -ENOENT;
+	}
+
+	rt->membase = devm_request_and_ioremap(&pdev->dev, res);
+	if (!rt->membase) {
+		dev_err(&pdev->dev, "failed to ioremap\n");
+		return -ENOMEM;
+	}
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "failed get clock rate\n");
+		return PTR_ERR(clk);
+	}
+
+	rt->timer_freq = clk_get_rate(clk) / TMR0CTL_PRESCALE_DIV;
+	if (!rt->timer_freq)
+		return -EINVAL;
+
+	rt->dev = &pdev->dev;
+	platform_set_drvdata(pdev, rt);
+
+	rt_timer_request(rt);
+	rt_timer_config(rt, 2);
+	rt_timer_enable(rt);
+
+	dev_info(&pdev->dev, "maximum frequncy is %luHz\n", rt->timer_freq);
+
+	return 0;
+}
+
+static int rt_timer_remove(struct platform_device *pdev)
+{
+	struct rt_timer *rt = platform_get_drvdata(pdev);
+
+	rt_timer_disable(rt);
+	rt_timer_free(rt);
+
+	return 0;
+}
+
+static const struct of_device_id rt_timer_match[] = {
+	{ .compatible = "ralink,rt2880-timer" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rt_timer_match);
+
+static struct platform_driver rt_timer_driver = {
+	.probe = rt_timer_probe,
+	.remove = rt_timer_remove,
+	.driver = {
+		.name		= "rt-timer",
+		.owner          = THIS_MODULE,
+		.of_match_table	= rt_timer_match
+	},
+};
+
+module_platform_driver(rt_timer_driver);
+
+MODULE_DESCRIPTION("Ralink RT2880 timer");
+MODULE_AUTHOR("John Crispin <blogic@openwrt.org");
+MODULE_LICENSE("GPL");
-- 
1.7.10.4

[PATCH] MIPS: ralink: add support for reset-controller API

[John Crispin]

Add a helper for reseting different devices on the SoC.

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 arch/mips/Kconfig         |    1 +
 arch/mips/ralink/common.h |    2 ++
 arch/mips/ralink/of.c     |    3 +++
 arch/mips/ralink/reset.c  |   62 +++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 68 insertions(+)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 45b4356..bb69e12 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -375,6 +375,7 @@ config MACH_VR41XX
 	select CSRC_R4K
 	select SYS_HAS_CPU_VR41XX
 	select ARCH_REQUIRE_GPIOLIB
+	select ARCH_HAS_RESET_CONTROLLER
 
 config NXP_STB220
 	bool "NXP STB220 board"
diff --git a/arch/mips/ralink/common.h b/arch/mips/ralink/common.h
index 83144c3..42dfd61 100644
--- a/arch/mips/ralink/common.h
+++ b/arch/mips/ralink/common.h
@@ -46,6 +46,8 @@ extern void ralink_of_remap(void);
 extern void ralink_clk_init(void);
 extern void ralink_clk_add(const char *dev, unsigned long rate);
 
+extern void ralink_rst_init(void);
+
 extern void prom_soc_init(struct ralink_soc_info *soc_info);
 
 __iomem void *plat_of_remap_node(const char *node);
diff --git a/arch/mips/ralink/of.c b/arch/mips/ralink/of.c
index f25ea5b..ce38d11 100644
--- a/arch/mips/ralink/of.c
+++ b/arch/mips/ralink/of.c
@@ -110,6 +110,9 @@ static int __init plat_of_setup(void)
 	if (of_platform_populate(NULL, of_ids, NULL, NULL))
 		panic("failed to populate DT\n");
 
+	/* make sure ithat the reset controller is setup early */
+	ralink_rst_init();
+
 	return 0;
 }
 
diff --git a/arch/mips/ralink/reset.c b/arch/mips/ralink/reset.c
index 22120e5..55c7ec5 100644
--- a/arch/mips/ralink/reset.c
+++ b/arch/mips/ralink/reset.c
@@ -10,6 +10,8 @@
 
 #include <linux/pm.h>
 #include <linux/io.h>
+#include <linux/of.h>
+#include <linux/reset-controller.h>
 
 #include <asm/reboot.h>
 
@@ -19,6 +21,66 @@
 #define SYSC_REG_RESET_CTRL     0x034
 #define RSTCTL_RESET_SYSTEM     BIT(0)
 
+static int ralink_assert_device(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	u32 val;
+
+	if (id < 8)
+		return -1;
+
+	val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
+	val |= BIT(id);
+	rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
+
+	return 0;
+}
+
+static int ralink_deassert_device(struct reset_controller_dev *rcdev,
+				  unsigned long id)
+{
+	u32 val;
+
+	if (id < 8)
+		return -1;
+
+	val = rt_sysc_r32(SYSC_REG_RESET_CTRL);
+	val &= ~BIT(id);
+	rt_sysc_w32(val, SYSC_REG_RESET_CTRL);
+
+	return 0;
+}
+
+static int ralink_reset_device(struct reset_controller_dev *rcdev,
+			       unsigned long id)
+{
+	ralink_assert_device(rcdev, id);
+	return ralink_deassert_device(rcdev, id);
+}
+
+static struct reset_control_ops reset_ops = {
+	.reset = ralink_reset_device,
+	.assert = ralink_assert_device,
+	.deassert = ralink_deassert_device,
+};
+
+static struct reset_controller_dev reset_dev = {
+	.ops			= &reset_ops,
+	.owner			= THIS_MODULE,
+	.nr_resets		= 32,
+	.of_reset_n_cells	= 1,
+};
+
+void ralink_rst_init(void)
+{
+	reset_dev.of_node = of_find_compatible_node(NULL, NULL,
+						"ralink,rt2880-reset");
+	if (!reset_dev.of_node)
+		pr_err("Failed to find reset controller node");
+	else
+		reset_controller_register(&reset_dev);
+}
+
 static void ralink_restart(char *command)
 {
 	local_irq_disable();
-- 
1.7.10.4

Re: [PATCH] MIPS: ralink: add support for periodic timer irq

[James Hogan]

Hi John,

On 08/08/13 12:05, John Crispin wrote:
> +static int rt_timer_probe(struct platform_device *pdev)
> +{
> +	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	struct rt_timer *rt;
> +	struct clk *clk;
> +
> +	if (!res) {
> +		dev_err(&pdev->dev, "no memory resource found\n");
> +		return -EINVAL;
> +	}

devm_request_and_ioremap already error checks res so you don't need to
check it yourself (see devm_request_and_ioremap kerneldoc comment in
lib/devres.c).

> +
> +	rt = devm_kzalloc(&pdev->dev, sizeof(*rt), GFP_KERNEL);
> +	if (!rt) {
> +		dev_err(&pdev->dev, "failed to allocate memory\n");
> +		return -ENOMEM;
> +	}
> +
> +	rt->irq = platform_get_irq(pdev, 0);
> +	if (!rt->irq) {
> +		dev_err(&pdev->dev, "failed to load irq\n");
> +		return -ENOENT;
> +	}
> +
> +	rt->membase = devm_request_and_ioremap(&pdev->dev, res);
> +	if (!rt->membase) {
> +		dev_err(&pdev->dev, "failed to ioremap\n");
> +		return -ENOMEM;
> +	}

Cheers
James

Re: [PATCH] MIPS: ralink: add support for periodic timer irq

[James Hogan]

Hi John,

On 08/08/13 12:05, John Crispin wrote:
> +static int rt_timer_probe(struct platform_device *pdev)
> +{
> +	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	struct rt_timer *rt;
> +	struct clk *clk;
> +
> +	if (!res) {
> +		dev_err(&pdev->dev, "no memory resource found\n");
> +		return -EINVAL;
> +	}

devm_request_and_ioremap already error checks res so you don't need to
check it yourself (see devm_request_and_ioremap kerneldoc comment in
lib/devres.c).

> +
> +	rt = devm_kzalloc(&pdev->dev, sizeof(*rt), GFP_KERNEL);
> +	if (!rt) {
> +		dev_err(&pdev->dev, "failed to allocate memory\n");
> +		return -ENOMEM;
> +	}
> +
> +	rt->irq = platform_get_irq(pdev, 0);
> +	if (!rt->irq) {
> +		dev_err(&pdev->dev, "failed to load irq\n");
> +		return -ENOENT;
> +	}
> +
> +	rt->membase = devm_request_and_ioremap(&pdev->dev, res);
> +	if (!rt->membase) {
> +		dev_err(&pdev->dev, "failed to ioremap\n");
> +		return -ENOMEM;
> +	}

Cheers
James