Merge branch 'exynos/pwm-clocksource' into late/multiplatform

This series from Tomasz Figa restores support for the pwm clocksource
in Exynos, which was broken during the conversion of the platform
to the common clk framework. The clocksource is only used in one
board in the mainline kernel (universal_c210), and this makes it
work for DT based probing as well as restoring the non-DT based
case.

* exynos/pwm-clocksource:
  ARM: dts: exynops4210: really add universal_c210 dts
  ARM: dts: exynos4210: Add basic dts file for universal_c210 board
  ARM: dts: exynos4: Add node for PWM device
  ARM: SAMSUNG: Do not register legacy timer interrupts on Exynos
  clocksource: samsung_pwm_timer: Work around rounding errors in clockevents core
  clocksource: samsung_pwm_timer: Correct programming of clock events
  clocksource: samsung_pwm_timer: Use proper clockevents max_delta
  clocksource: samsung_pwm_timer: Add support for non-DT platforms
  clocksource: samsung_pwm_timer: Drop unused samsung_pwm struct
  clocksource: samsung_pwm_timer: Keep all driver data in a structure
  clocksource: samsung_pwm_timer: Make PWM spinlock global
  clocksource: samsung_pwm_timer: Let platforms select the driver
  Documentation: Add device tree bindings for Samsung PWM timers
  clocksource: add samsung pwm timer driver

Conflicts:
	arch/arm/boot/dts/Makefile
	arch/arm/mach-exynos/common.c
	drivers/clocksource/Kconfig
	drivers/clocksource/Makefile
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Documentation/devicetree/bindings/pwm/pwm-samsung.txt

+* Samsung PWM timers
+
+Samsung SoCs contain PWM timer blocks which can be used for system clock source
+and clock event timers, as well as to drive SoC outputs with PWM signal. Each
+PWM timer block provides 5 PWM channels (not all of them can drive physical
+outputs - see SoC and board manual).
+
+Be aware that the clocksource driver supports only uniprocessor systems.
+
+Required properties:
+- compatible : should be one of following:
+    samsung,s3c2410-pwm - for 16-bit timers present on S3C24xx SoCs
+    samsung,s3c6400-pwm - for 32-bit timers present on S3C64xx SoCs
+    samsung,s5p6440-pwm - for 32-bit timers present on S5P64x0 SoCs
+    samsung,s5pc100-pwm - for 32-bit timers present on S5PC100, S5PV210,
+			  Exynos4210 rev0 SoCs
+    samsung,exynos4210-pwm - for 32-bit timers present on Exynos4210,
+                          Exynos4x12 and Exynos5250 SoCs
+- reg: base address and size of register area
+- interrupts: list of timer interrupts (one interrupt per timer, starting at
+  timer 0)
+- #pwm-cells: number of cells used for PWM specifier - must be 3
+   the specifier format is as follows:
+     - phandle to PWM controller node
+     - index of PWM channel (from 0 to 4)
+     - PWM signal period in nanoseconds
+     - bitmask of optional PWM flags:
+        0x1 - invert PWM signal
+
+Optional properties:
+- samsung,pwm-outputs: list of PWM channels used as PWM outputs on particular
+    platform - an array of up to 5 elements being indices of PWM channels
+    (from 0 to 4), the order does not matter.
+
+Example:
+	pwm@7f006000 {
+		compatible = "samsung,s3c6400-pwm";
+		reg = <0x7f006000 0x1000>;
+		interrupt-parent = <&vic0>;
+		interrupts = <23>, <24>, <25>, <27>, <28>;
+		samsung,pwm-outputs = <0>, <1>;
+		#pwm-cells = <3>;
+	}

arch/arm/boot/dts/Makefile

@@ -42,6 +42,7 @@ dtb-$(CONFIG_ARCH_DOVE) += dove-cm-a510.dtb \
 dtb-$(CONFIG_ARCH_EXYNOS) += exynos4210-origen.dtb \
 	exynos4210-smdkv310.dtb \
 	exynos4210-trats.dtb \
+	exynos4210-universal_c210.dtb \
 	exynos4412-odroidx.dtb \
 	exynos4412-smdk4412.dtb \
 	exynos4412-origen.dtb \

arch/arm/boot/dts/exynos4.dtsi

@@ -316,6 +316,14 @@ spi_2: spi@13940000 {
 		status = "disabled";
 	};
 
+	pwm@139D0000 {
+		compatible = "samsung,exynos4210-pwm";
+		reg = <0x139D0000 0x1000>;
+		interrupts = <0 37 0>, <0 38 0>, <0 39 0>, <0 40 0>, <0 41 0>;
+		#pwm-cells = <2>;
+		status = "disabled";
+	};
+
 	amba {
 		#address-cells = <1>;
 		#size-cells = <1>;

arch/arm/boot/dts/exynos4210-universal_c210.dts

+/*
+ * Samsung's Exynos4210 based Universal C210 board device tree source
+ *
+ * Copyright (c) 2012-2013 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Device tree source file for Samsung's Universal C210 board which is based on
+ * Samsung's Exynos4210 rev0 SoC.
+ *
+ * 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.
+*/
+
+/dts-v1/;
+/include/ "exynos4210.dtsi"
+
+/ {
+	model = "Samsung Universal C210 based on Exynos4210 rev0";
+	compatible = "samsung,universal_c210", "samsung,exynos4210";
+
+	memory {
+		reg =  <0x40000000 0x10000000
+			0x50000000 0x10000000>;
+	};
+
+	chosen {
+		bootargs = "console=ttySAC2,115200N8 root=/dev/mmcblk0p5 rw rootwait earlyprintk panic=5 maxcpus=1";
+	};
+
+	mct@10050000 {
+		compatible = "none";
+	};
+
+	fixed-rate-clocks {
+		xxti {
+			compatible = "samsung,clock-xxti";
+			clock-frequency = <0>;
+		};
+
+		xusbxti {
+			compatible = "samsung,clock-xusbxti";
+			clock-frequency = <24000000>;
+		};
+	};
+
+	vemmc_reg: voltage-regulator {
+	        compatible = "regulator-fixed";
+		regulator-name = "VMEM_VDD_2_8V";
+		regulator-min-microvolt = <2800000>;
+		regulator-max-microvolt = <2800000>;
+		gpio = <&gpe1 3 0>;
+		enable-active-high;
+	};
+
+	sdhci_emmc: sdhci@12510000 {
+		bus-width = <8>;
+		non-removable;
+		pinctrl-0 = <&sd0_clk &sd0_cmd &sd0_bus8>;
+		pinctrl-names = "default";
+		vmmc-supply = <&vemmc_reg>;
+		status = "okay";
+	};
+
+	serial@13800000 {
+		status = "okay";
+	};
+
+	serial@13810000 {
+		status = "okay";
+	};
+
+	serial@13820000 {
+		status = "okay";
+	};
+
+	serial@13830000 {
+		status = "okay";
+	};
+
+	gpio-keys {
+		compatible = "gpio-keys";
+
+		vol-up-key {
+			gpios = <&gpx2 0 1>;
+			linux,code = <115>;
+			label = "volume up";
+			debounce-interval = <1>;
+		};
+
+		vol-down-key {
+			gpios = <&gpx2 1 1>;
+			linux,code = <114>;
+			label = "volume down";
+			debounce-interval = <1>;
+		};
+
+		config-key {
+			gpios = <&gpx2 2 1>;
+			linux,code = <171>;
+			label = "config";
+			debounce-interval = <1>;
+			gpio-key,wakeup;
+		};
+
+		camera-key {
+			gpios = <&gpx2 3 1>;
+			linux,code = <212>;
+			label = "camera";
+			debounce-interval = <1>;
+		};
+
+		power-key {
+			gpios = <&gpx2 7 1>;
+			linux,code = <116>;
+			label = "power";
+			debounce-interval = <1>;
+			gpio-key,wakeup;
+		};
+
+		ok-key {
+			gpios = <&gpx3 5 1>;
+			linux,code = <352>;
+			label = "ok";
+			debounce-interval = <1>;
+		};
+	};
+
+	tsp_reg: voltage-regulator {
+	        compatible = "regulator-fixed";
+		regulator-name = "TSP_2_8V";
+		regulator-min-microvolt = <2800000>;
+		regulator-max-microvolt = <2800000>;
+		gpio = <&gpe2 3 0>;
+		enable-active-high;
+	};
+
+	i2c@13890000 {
+		samsung,i2c-sda-delay = <100>;
+		samsung,i2c-slave-addr = <0x10>;
+		samsung,i2c-max-bus-freq = <100000>;
+		pinctrl-0 = <&i2c3_bus>;
+		pinctrl-names = "default";
+		status = "okay";
+
+		tsp@4a {
+			/* TBD: Atmel maXtouch touchscreen */
+			reg = <0x4a>;
+		};
+	};
+
+	i2c@138B0000 {
+		samsung,i2c-sda-delay = <100>;
+		samsung,i2c-slave-addr = <0x10>;
+		samsung,i2c-max-bus-freq = <100000>;
+		pinctrl-0 = <&i2c5_bus>;
+		pinctrl-names = "default";
+		status = "okay";
+
+		vdd_arm_reg: pmic@60 {
+			compatible = "maxim,max8952";
+			reg = <0x60>;
+
+			max8952,vid-gpios = <&gpx0 3 0>, <&gpx0 4 0>;
+			max8952,default-mode = <0>;
+			max8952,dvs-mode-microvolt = <1250000>, <1200000>,
+							<1050000>, <950000>;
+			max8952,sync-freq = <0>;
+			max8952,ramp-speed = <0>;
+
+			regulator-name = "vdd_arm";
+			regulator-min-microvolt = <770000>;
+			regulator-max-microvolt = <1400000>;
+			regulator-always-on;
+			regulator-boot-on;
+		};
+
+		pmic@66 {
+			compatible = "national,lp3974";
+			reg = <0x66>;
+
+			max8998,pmic-buck1-default-dvs-idx = <0>;
+			max8998,pmic-buck1-dvs-gpios = <&gpx0 5 0>,
+							<&gpx0 6 0>;
+			max8998,pmic-buck1-dvs-voltage = <1100000>, <1000000>,
+							<1100000>, <1000000>;
+
+			max8998,pmic-buck2-default-dvs-idx = <0>;
+			max8998,pmic-buck2-dvs-gpio = <&gpe2 0 0>;
+			max8998,pmic-buck2-dvs-voltage = <1200000>, <1100000>;
+
+			regulators {
+				ldo2_reg: LDO2 {
+					regulator-name = "VALIVE_1.2V";
+					regulator-min-microvolt = <1200000>;
+					regulator-max-microvolt = <1200000>;
+					regulator-always-on;
+				};
+
+				ldo3_reg: LDO3 {
+					regulator-name = "VUSB+MIPI_1.1V";
+					regulator-min-microvolt = <1100000>;
+					regulator-max-microvolt = <1100000>;
+				};
+
+				ldo4_reg: LDO4 {
+					regulator-name = "VADC_3.3V";
+					regulator-min-microvolt = <3300000>;
+					regulator-max-microvolt = <3300000>;
+				};
+
+				ldo5_reg: LDO5 {
+					regulator-name = "VTF_2.8V";
+					regulator-min-microvolt = <2800000>;
+					regulator-max-microvolt = <2800000>;
+				};
+
+				ldo6_reg: LDO6 {
+					regulator-name = "LDO6";
+					regulator-min-microvolt = <2000000>;
+					regulator-max-microvolt = <2000000>;
+				};
+
+				ldo7_reg: LDO7 {
+					regulator-name = "VLCD+VMIPI_1.8V";
+					regulator-min-microvolt = <1800000>;
+					regulator-max-microvolt = <1800000>;
+				};
+
+				ldo8_reg: LDO8 {
+					regulator-name = "VUSB+VDAC_3.3V";
+					regulator-min-microvolt = <3300000>;
+					regulator-max-microvolt = <3300000>;
+				};
+
+				ldo9_reg: LDO9 {
+					regulator-name = "VCC_2.8V";
+					regulator-min-microvolt = <2800000>;
+					regulator-max-microvolt = <2800000>;
+					regulator-always-on;
+				};
+
+				ldo10_reg: LDO10 {
+					regulator-name = "VPLL_1.1V";
+					regulator-min-microvolt = <1100000>;
+					regulator-max-microvolt = <1100000>;
+					regulator-boot-on;
+					regulator-always-on;
+				};
+
+				ldo11_reg: LDO11 {
+					regulator-name = "CAM_AF_3.3V";
+					regulator-min-microvolt = <3300000>;
+					regulator-max-microvolt = <3300000>;
+				};
+
+				ldo12_reg: LDO12 {
+					regulator-name = "PS_2.8V";
+					regulator-min-microvolt = <2800000>;
+					regulator-max-microvolt = <2800000>;
+				};
+
+				ldo13_reg: LDO13 {
+					regulator-name = "VHIC_1.2V";
+					regulator-min-microvolt = <1200000>;
+					regulator-max-microvolt = <1200000>;
+				};
+
+				ldo14_reg: LDO14 {
+					regulator-name = "CAM_I_HOST_1.8V";
+					regulator-min-microvolt = <1800000>;
+					regulator-max-microvolt = <1800000>;
+				};
+
+				ldo15_reg: LDO15 {
+					regulator-name = "CAM_S_DIG+FM33_CORE_1.2V";
+					regulator-min-microvolt = <1200000>;
+					regulator-max-microvolt = <1200000>;
+				};
+
+				ldo16_reg: LDO16 {
+					regulator-name = "CAM_S_ANA_2.8V";
+					regulator-min-microvolt = <2800000>;
+					regulator-max-microvolt = <2800000>;
+				};
+
+				ldo17_reg: LDO17 {
+					regulator-name = "VCC_3.0V_LCD";
+					regulator-min-microvolt = <3000000>;
+					regulator-max-microvolt = <3000000>;
+				};
+
+				buck1_reg: BUCK1 {
+					regulator-name = "VINT_1.1V";
+					regulator-min-microvolt = <750000>;
+					regulator-max-microvolt = <1500000>;
+					regulator-boot-on;
+					regulator-always-on;
+				};
+
+				buck2_reg: BUCK2 {
+					regulator-name = "VG3D_1.1V";
+					regulator-min-microvolt = <750000>;
+					regulator-max-microvolt = <1500000>;
+					regulator-boot-on;
+				};
+
+				buck3_reg: BUCK3 {
+					regulator-name = "VCC_1.8V";
+					regulator-min-microvolt = <1800000>;
+					regulator-max-microvolt = <1800000>;
+					regulator-always-on;
+				};
+
+				buck4_reg: BUCK4 {
+					regulator-name = "VMEM_1.2V";
+					regulator-min-microvolt = <1200000>;
+					regulator-max-microvolt = <1200000>;
+					regulator-always-on;
+				};
+
+				ap32khz_reg: EN32KHz-AP {
+					regulator-name = "32KHz AP";
+					regulator-always-on;
+				};
+
+				cp32khz_reg: EN32KHz-CP {
+					regulator-name = "32KHz CP";
+				};
+
+				vichg_reg: ENVICHG {
+					regulator-name = "VICHG";
+				};
+
+				safeout1_reg: ESAFEOUT1 {
+					regulator-name = "SAFEOUT1";
+					regulator-always-on;
+				};
+
+				safeout2_reg: ESAFEOUT2 {
+					regulator-name = "SAFEOUT2";
+					regulator-boot-on;
+				};
+			};
+		};
+	};
+
+	pwm@139D0000 {
+		compatible = "samsung,s5p6440-pwm";
+		status = "okay";
+	};
+};

arch/arm/mach-exynos/common.c

@@ -449,13 +449,6 @@ void __init exynos4_init_irq(void)
 	if (!of_have_populated_dt())
 		combiner_init(S5P_VA_COMBINER_BASE, NULL,
 			      max_combiner_nr(), COMBINER_IRQ(0, 0));
-
-	/*
-	 * The parameters of s5p_init_irq() are for VIC init.
-	 * Theses parameters should be NULL and 0 because EXYNOS4
-	 * uses GIC instead of VIC.
-	 */
-	s5p_init_irq(NULL, 0);
 }
 
 void __init exynos5_init_irq(void)
@@ -463,14 +456,6 @@ void __init exynos5_init_irq(void)
 #ifdef CONFIG_OF
 	irqchip_init();
 #endif
-	/*
-	 * The parameters of s5p_init_irq() are for VIC init.
-	 * Theses parameters should be NULL and 0 because EXYNOS4
-	 * uses GIC instead of VIC.
-	 */
-	if (!of_machine_is_compatible("samsung,exynos5440"))
-		s5p_init_irq(NULL, 0);
-
 	gic_arch_extn.irq_set_wake = s3c_irq_wake;
 }
 

arch/arm/plat-samsung/Kconfig

@@ -105,9 +105,9 @@ config SAMSUNG_IRQ_VIC_TIMER
          Internal configuration to build the VIC timer interrupt code.
 
 config S5P_IRQ
-	def_bool (ARCH_S5P64X0 || ARCH_S5PC100 || ARCH_S5PV210 || ARCH_EXYNOS)
+	def_bool (ARCH_S5P64X0 || ARCH_S5PC100 || ARCH_S5PV210)
 	help
-	  Support common interrup part for ARCH_S5P and ARCH_EXYNOS SoCs
+	  Support common interrupt part for ARCH_S5P SoCs
 
 config S5P_EXT_INT
 	bool

drivers/clocksource/Kconfig

@@ -75,3 +75,12 @@ config CLKSRC_EXYNOS_MCT
 	def_bool y if ARCH_EXYNOS
 	help
 	  Support for Multi Core Timer controller on Exynos SoCs.
+
+config CLKSRC_SAMSUNG_PWM
+	bool
+	select CLKSRC_MMIO
+	help
+	  This is a new clocksource driver for the PWM timer found in
+	  Samsung S3C, S5P and Exynos SoCs, replacing an earlier driver
+	  for all devicetree enabled platforms. This driver will be
+	  needed only on systems that do not have the Exynos MCT available.

drivers/clocksource/Makefile

@@ -21,6 +21,7 @@ obj-$(CONFIG_ARCH_TEGRA)	+= tegra20_timer.o
 obj-$(CONFIG_VT8500_TIMER)	+= vt8500_timer.o
 obj-$(CONFIG_CADENCE_TTC_TIMER)	+= cadence_ttc_timer.o
 obj-$(CONFIG_CLKSRC_EXYNOS_MCT)	+= exynos_mct.o
+obj-$(CONFIG_CLKSRC_SAMSUNG_PWM)	+= samsung_pwm_timer.o
 
 obj-$(CONFIG_ARM_ARCH_TIMER)		+= arm_arch_timer.o
 obj-$(CONFIG_CLKSRC_METAG_GENERIC)	+= metag_generic.o

drivers/clocksource/samsung_pwm_timer.c

+/*
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com/
+ *
+ * samsung - Common hr-timer support (s3c and s5p)
+ *
+ * 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.
+*/
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <clocksource/samsung_pwm.h>
+
+#include <asm/sched_clock.h>
+
+/*
+ * Clocksource driver
+ */
+
+#define REG_TCFG0			0x00
+#define REG_TCFG1			0x04
+#define REG_TCON			0x08
+#define REG_TINT_CSTAT			0x44
+
+#define REG_TCNTB(chan)			(0x0c + 12 * (chan))
+#define REG_TCMPB(chan)			(0x10 + 12 * (chan))
+
+#define TCFG0_PRESCALER_MASK		0xff
+#define TCFG0_PRESCALER1_SHIFT		8
+
+#define TCFG1_SHIFT(x)	  		((x) * 4)
+#define TCFG1_MUX_MASK	  		0xf
+
+#define TCON_START(chan)		(1 << (4 * (chan) + 0))
+#define TCON_MANUALUPDATE(chan)		(1 << (4 * (chan) + 1))
+#define TCON_INVERT(chan)		(1 << (4 * (chan) + 2))
+#define TCON_AUTORELOAD(chan)		(1 << (4 * (chan) + 3))
+
+DEFINE_SPINLOCK(samsung_pwm_lock);
+EXPORT_SYMBOL(samsung_pwm_lock);
+
+struct samsung_pwm_clocksource {
+	void __iomem *base;
+	unsigned int irq[SAMSUNG_PWM_NUM];
+	struct samsung_pwm_variant variant;
+
+	struct clk *timerclk;
+
+	unsigned int event_id;
+	unsigned int source_id;
+	unsigned int tcnt_max;
+	unsigned int tscaler_div;
+	unsigned int tdiv;
+
+	unsigned long clock_count_per_tick;
+};
+
+static struct samsung_pwm_clocksource pwm;
+
+static void samsung_timer_set_prescale(unsigned int channel, u16 prescale)
+{
+	unsigned long flags;
+	u8 shift = 0;
+	u32 reg;
+
+	if (channel >= 2)
+		shift = TCFG0_PRESCALER1_SHIFT;
+
+	spin_lock_irqsave(&samsung_pwm_lock, flags);
+
+	reg = readl(pwm.base + REG_TCFG0);
+	reg &= ~(TCFG0_PRESCALER_MASK << shift);
+	reg |= (prescale - 1) << shift;
+	writel(reg, pwm.base + REG_TCFG0);
+
+	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+}
+
+static void samsung_timer_set_divisor(unsigned int channel, u8 divisor)
+{
+	u8 shift = TCFG1_SHIFT(channel);
+	unsigned long flags;
+	u32 reg;
+	u8 bits;
+
+	bits = (fls(divisor) - 1) - pwm.variant.div_base;
+
+	spin_lock_irqsave(&samsung_pwm_lock, flags);
+
+	reg = readl(pwm.base + REG_TCFG1);
+	reg &= ~(TCFG1_MUX_MASK << shift);
+	reg |= bits << shift;
+	writel(reg, pwm.base + REG_TCFG1);
+
+	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+}
+
+static void samsung_time_stop(unsigned int channel)
+{
+	unsigned long tcon;
+	unsigned long flags;
+
+	if (channel > 0)
+		++channel;
+
+	spin_lock_irqsave(&samsung_pwm_lock, flags);
+
+	tcon = __raw_readl(pwm.base + REG_TCON);
+	tcon &= ~TCON_START(channel);
+	__raw_writel(tcon, pwm.base + REG_TCON);
+
+	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+}
+
+static void samsung_time_setup(unsigned int channel, unsigned long tcnt)
+{
+	unsigned long tcon;
+	unsigned long flags;
+	unsigned int tcon_chan = channel;
+
+	if (tcon_chan > 0)
+		++tcon_chan;
+
+	spin_lock_irqsave(&samsung_pwm_lock, flags);
+
+	tcon = __raw_readl(pwm.base + REG_TCON);
+
+	tcon &= ~(TCON_START(tcon_chan) | TCON_AUTORELOAD(tcon_chan));
+	tcon |= TCON_MANUALUPDATE(tcon_chan);
+
+	__raw_writel(tcnt, pwm.base + REG_TCNTB(channel));
+	__raw_writel(tcnt, pwm.base + REG_TCMPB(channel));
+	__raw_writel(tcon, pwm.base + REG_TCON);
+
+	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+}
+
+static void samsung_time_start(unsigned int channel, bool periodic)
+{
+	unsigned long tcon;
+	unsigned long flags;
+
+	if (channel > 0)
+		++channel;
+
+	spin_lock_irqsave(&samsung_pwm_lock, flags);
+
+	tcon = __raw_readl(pwm.base + REG_TCON);
+
+	tcon &= ~TCON_MANUALUPDATE(channel);
+	tcon |= TCON_START(channel);
+
+	if (periodic)
+		tcon |= TCON_AUTORELOAD(channel);
+	else
+		tcon &= ~TCON_AUTORELOAD(channel);
+
+	__raw_writel(tcon, pwm.base + REG_TCON);
+
+	spin_unlock_irqrestore(&samsung_pwm_lock, flags);
+}
+
+static int samsung_set_next_event(unsigned long cycles,
+				struct clock_event_device *evt)
+{
+	/*
+	 * This check is needed to account for internal rounding
+	 * errors inside clockevents core, which might result in
+	 * passing cycles = 0, which in turn would not generate any
+	 * timer interrupt and hang the system.
+	 *
+	 * Another solution would be to set up the clockevent device
+	 * with min_delta = 2, but this would unnecessarily increase
+	 * the minimum sleep period.
+	 */
+	if (!cycles)
+		cycles = 1;
+
+	samsung_time_setup(pwm.event_id, cycles);
+	samsung_time_start(pwm.event_id, false);
+
+	return 0;
+}
+
+static void samsung_timer_resume(void)
+{
+	/* event timer restart */
+	samsung_time_setup(pwm.event_id, pwm.clock_count_per_tick - 1);
+	samsung_time_start(pwm.event_id, true);
+
+	/* source timer restart */
+	samsung_time_setup(pwm.source_id, pwm.tcnt_max);
+	samsung_time_start(pwm.source_id, true);
+}
+
+static void samsung_set_mode(enum clock_event_mode mode,
+				struct clock_event_device *evt)
+{
+	samsung_time_stop(pwm.event_id);
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		samsung_time_setup(pwm.event_id, pwm.clock_count_per_tick - 1);
+		samsung_time_start(pwm.event_id, true);
+		break;
+
+	case CLOCK_EVT_MODE_ONESHOT:
+		break;
+
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		break;
+
+	case CLOCK_EVT_MODE_RESUME:
+		samsung_timer_resume();
+		break;
+	}
+}
+
+static struct clock_event_device time_event_device = {
+	.name		= "samsung_event_timer",
+	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.rating		= 200,
+	.set_next_event	= samsung_set_next_event,
+	.set_mode	= samsung_set_mode,
+};
+
+static irqreturn_t samsung_clock_event_isr(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = dev_id;
+
+	if (pwm.variant.has_tint_cstat) {
+		u32 mask = (1 << pwm.event_id);
+		writel(mask | (mask << 5), pwm.base + REG_TINT_CSTAT);
+	}
+
+	evt->event_handler(evt);
+
+	return IRQ_HANDLED;
+}
+
+static struct irqaction samsung_clock_event_irq = {
+	.name		= "samsung_time_irq",
+	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+	.handler	= samsung_clock_event_isr,
+	.dev_id		= &time_event_device,
+};
+
+static void __init samsung_clockevent_init(void)
+{
+	unsigned long pclk;
+	unsigned long clock_rate;
+	unsigned int irq_number;
+
+	pclk = clk_get_rate(pwm.timerclk);
+
+	samsung_timer_set_prescale(pwm.event_id, pwm.tscaler_div);
+	samsung_timer_set_divisor(pwm.event_id, pwm.tdiv);
+
+	clock_rate = pclk / (pwm.tscaler_div * pwm.tdiv);
+	pwm.clock_count_per_tick = clock_rate / HZ;
+
+	time_event_device.cpumask = cpumask_of(0);
+	clockevents_config_and_register(&time_event_device,
+						clock_rate, 1, pwm.tcnt_max);
+
+	irq_number = pwm.irq[pwm.event_id];
+	setup_irq(irq_number, &samsung_clock_event_irq);
+
+	if (pwm.variant.has_tint_cstat) {
+		u32 mask = (1 << pwm.event_id);
+		writel(mask | (mask << 5), pwm.base + REG_TINT_CSTAT);
+	}
+}
+
+static void __iomem *samsung_timer_reg(void)
+{
+	switch (pwm.source_id) {
+	case 0:
+	case 1:
+	case 2:
+	case 3:
+		return pwm.base + pwm.source_id * 0x0c + 0x14;
+
+	case 4:
+		return pwm.base + 0x40;
+
+	default:
+		BUG();
+	}
+}
+
+/*
+ * Override the global weak sched_clock symbol with this
+ * local implementation which uses the clocksource to get some
+ * better resolution when scheduling the kernel. We accept that
+ * this wraps around for now, since it is just a relative time
+ * stamp. (Inspired by U300 implementation.)
+ */
+static u32 notrace samsung_read_sched_clock(void)
+{
+	void __iomem *reg = samsung_timer_reg();
+
+	if (!reg)
+		return 0;
+
+	return ~__raw_readl(reg);
+}
+
+static void __init samsung_clocksource_init(void)
+{
+	void __iomem *reg = samsung_timer_reg();
+	unsigned long pclk;
+	unsigned long clock_rate;
+	int ret;
+
+	pclk = clk_get_rate(pwm.timerclk);
+
+	samsung_timer_set_prescale(pwm.source_id, pwm.tscaler_div);
+	samsung_timer_set_divisor(pwm.source_id, pwm.tdiv);
+
+	clock_rate = pclk / (pwm.tscaler_div * pwm.tdiv);
+
+	samsung_time_setup(pwm.source_id, pwm.tcnt_max);
+	samsung_time_start(pwm.source_id, true);
+
+	setup_sched_clock(samsung_read_sched_clock,
+						pwm.variant.bits, clock_rate);
+
+	ret = clocksource_mmio_init(reg, "samsung_clocksource_timer",
+					clock_rate, 250, pwm.variant.bits,
+					clocksource_mmio_readl_down);
+	if (ret)
+		panic("samsung_clocksource_timer: can't register clocksource\n");
+}
+
+static void __init samsung_timer_resources(void)
+{
+	pwm.timerclk = clk_get(NULL, "timers");
+	if (IS_ERR(pwm.timerclk))
+		panic("failed to get timers clock for timer");
+
+	clk_prepare_enable(pwm.timerclk);
+
+	pwm.tcnt_max = (1UL << pwm.variant.bits) - 1;
+	if (pwm.variant.bits == 16) {
+		pwm.tscaler_div = 25;
+		pwm.tdiv = 2;
+	} else {
+		pwm.tscaler_div = 2;
+		pwm.tdiv = 1;
+	}
+}
+
+/*
+ * PWM master driver
+ */
+static void __init _samsung_pwm_clocksource_init(void)
+{
+	u8 mask;
+	int channel;
+
+	mask = ~pwm.variant.output_mask & ((1 << SAMSUNG_PWM_NUM) - 1);
+	channel = fls(mask) - 1;
+	if (channel < 0)
+		panic("failed to find PWM channel for clocksource");
+	pwm.source_id = channel;
+
+	mask &= ~(1 << channel);
+	channel = fls(mask) - 1;
+	if (channel < 0)
+		panic("failed to find PWM channel for clock event");
+	pwm.event_id = channel;
+
+	samsung_timer_resources();
+	samsung_clockevent_init();
+	samsung_clocksource_init();
+}
+
+void __init samsung_pwm_clocksource_init(void __iomem *base,
+			unsigned int *irqs, struct samsung_pwm_variant *variant)
+{
+	pwm.base = base;
+	memcpy(&pwm.variant, variant, sizeof(pwm.variant));
+	memcpy(pwm.irq, irqs, SAMSUNG_PWM_NUM * sizeof(*irqs));
+
+	_samsung_pwm_clocksource_init();
+}
+
+#ifdef CONFIG_CLKSRC_OF
+static void __init samsung_pwm_alloc(struct device_node *np,
+				     const struct samsung_pwm_variant *variant)
+{
+	struct resource res;
+	struct property *prop;
+	const __be32 *cur;
+	u32 val;
+	int i;
+
+	memcpy(&pwm.variant, variant, sizeof(pwm.variant));
+	for (i = 0; i < SAMSUNG_PWM_NUM; ++i)
+		pwm.irq[i] = irq_of_parse_and_map(np, i);
+
+	of_property_for_each_u32(np, "samsung,pwm-outputs", prop, cur, val) {
+		if (val >= SAMSUNG_PWM_NUM) {
+			pr_warning("%s: invalid channel index in samsung,pwm-outputs property\n",
+								__func__);
+			continue;
+		}
+		pwm.variant.output_mask |= 1 << val;
+	}
+
+	of_address_to_resource(np, 0, &res);
+	if (!request_mem_region(res.start,
+				resource_size(&res), "samsung-pwm")) {
+		pr_err("%s: failed to request IO mem region\n", __func__);
+		return;
+	}
+
+	pwm.base = ioremap(res.start, resource_size(&res));
+	if (!pwm.base) {
+		pr_err("%s: failed to map PWM registers\n", __func__);
+		release_mem_region(res.start, resource_size(&res));
+		return;
+	}
+
+	_samsung_pwm_clocksource_init();
+}
+
+static const struct samsung_pwm_variant s3c24xx_variant = {
+	.bits		= 16,
+	.div_base	= 1,
+	.has_tint_cstat	= false,
+	.tclk_mask	= (1 << 4),
+};
+
+static void __init s3c2410_pwm_clocksource_init(struct device_node *np)
+{
+	samsung_pwm_alloc(np, &s3c24xx_variant);
+}
+CLOCKSOURCE_OF_DECLARE(s3c2410_pwm, "samsung,s3c2410-pwm", s3c2410_pwm_clocksource_init);
+
+static const struct samsung_pwm_variant s3c64xx_variant = {
+	.bits		= 32,
+	.div_base	= 0,
+	.has_tint_cstat	= true,
+	.tclk_mask	= (1 << 7) | (1 << 6) | (1 << 5),
+};
+
+static void __init s3c64xx_pwm_clocksource_init(struct device_node *np)
+{
+	samsung_pwm_alloc(np, &s3c64xx_variant);
+}
+CLOCKSOURCE_OF_DECLARE(s3c6400_pwm, "samsung,s3c6400-pwm", s3c64xx_pwm_clocksource_init);
+
+static const struct samsung_pwm_variant s5p64x0_variant = {
+	.bits		= 32,
+	.div_base	= 0,
+	.has_tint_cstat	= true,
+	.tclk_mask	= 0,
+};
+
+static void __init s5p64x0_pwm_clocksource_init(struct device_node *np)
+{
+	samsung_pwm_alloc(np, &s5p64x0_variant);
+}
+CLOCKSOURCE_OF_DECLARE(s5p6440_pwm, "samsung,s5p6440-pwm", s5p64x0_pwm_clocksource_init);
+
+static const struct samsung_pwm_variant s5p_variant = {
+	.bits		= 32,
+	.div_base	= 0,
+	.has_tint_cstat	= true,
+	.tclk_mask	= (1 << 5),
+};
+
+static void __init s5p_pwm_clocksource_init(struct device_node *np)
+{
+	samsung_pwm_alloc(np, &s5p_variant);
+}
+CLOCKSOURCE_OF_DECLARE(s5pc100_pwm, "samsung,s5pc100-pwm", s5p_pwm_clocksource_init);
+#endif

include/clocksource/samsung_pwm.h

+/*
+ * Copyright (C) 2013 Samsung Electronics Co., Ltd.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __CLOCKSOURCE_SAMSUNG_PWM_H
+#define __CLOCKSOURCE_SAMSUNG_PWM_H
+
+#include <linux/spinlock.h>
+
+#define SAMSUNG_PWM_NUM		5
+
+extern spinlock_t samsung_pwm_lock;
+
+struct samsung_pwm_variant {
+	u8 bits;
+	u8 div_base;
+	u8 tclk_mask;
+	u8 output_mask;
+	bool has_tint_cstat;
+};
+
+void samsung_pwm_clocksource_init(void __iomem *base,
+		unsigned int *irqs, struct samsung_pwm_variant *variant);
+
+#endif /* __CLOCKSOURCE_SAMSUNG_PWM_H */