This patch adds timer support for S5P6440 CPU. Signed-off-by: Kukjin Kim <kgene.kim@xxxxxxxxxxx> Signed-off-by: Adityapratap Sharma <aditya.ps@xxxxxxxxxxx> Signed-off-by: Thomas Abraham <thomas.ab@xxxxxxxxxxx> Signed-off-by: Atul Dahiya <atul.dahiya@xxxxxxxxxxx> --- arch/arm/mach-s5p6440/include/mach/pwm-clock.h | 58 ++++++ arch/arm/mach-s5p6440/include/mach/tick.h | 24 +++ arch/arm/plat-s5p/time.c | 227 ++++++++++++++++++++++++ 3 files changed, 309 insertions(+), 0 deletions(-) create mode 100644 arch/arm/mach-s5p6440/include/mach/pwm-clock.h create mode 100644 arch/arm/mach-s5p6440/include/mach/tick.h create mode 100644 arch/arm/plat-s5p/time.c diff --git a/arch/arm/mach-s5p6440/include/mach/pwm-clock.h b/arch/arm/mach-s5p6440/include/mach/pwm-clock.h new file mode 100644 index 0000000..f6a6c30 --- /dev/null +++ b/arch/arm/mach-s5p6440/include/mach/pwm-clock.h @@ -0,0 +1,58 @@ +/* linux/arch/arm/mach-s5p6440/include/mach/pwm-clock.h + * + * Copyright 2009 Samsung Electronics Co., Ltd. + * http://www.samsung.com/ + * + * S5P6440 - pwm clock and timer support + * + * 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. +*/ + +/** + * pwm_cfg_src_is_tclk() - return whether the given mux config is a tclk + * @cfg: The timer TCFG1 register bits shifted down to 0. + * + * Return true if the given configuration from TCFG1 is a TCLK instead + * any of the TDIV clocks. + */ +static inline int pwm_cfg_src_is_tclk(unsigned long tcfg) +{ + return tcfg == S3C2410_TCFG1_MUX_TCLK; +} + +/** + * tcfg_to_divisor() - convert tcfg1 setting to a divisor + * @tcfg1: The tcfg1 setting, shifted down. + * + * Get the divisor value for the given tcfg1 setting. We assume the + * caller has already checked to see if this is not a TCLK source. + */ +static inline unsigned long tcfg_to_divisor(unsigned long tcfg1) +{ + return 1 << (1 + tcfg1); +} + +/** + * pwm_tdiv_has_div1() - does the tdiv setting have a /1 + * + * Return true if we have a /1 in the tdiv setting. + */ +static inline unsigned int pwm_tdiv_has_div1(void) +{ + return 0; +} + +/** + * pwm_tdiv_div_bits() - calculate TCFG1 divisor value. + * @div: The divisor to calculate the bit information for. + * + * Turn a divisor into the necessary bit field for TCFG1. + */ +static inline unsigned long pwm_tdiv_div_bits(unsigned int div) +{ + return ilog2(div) - 1; +} + +#define S3C_TCFG1_MUX_TCLK S3C2410_TCFG1_MUX_TCLK diff --git a/arch/arm/mach-s5p6440/include/mach/tick.h b/arch/arm/mach-s5p6440/include/mach/tick.h new file mode 100644 index 0000000..70d1f37 --- /dev/null +++ b/arch/arm/mach-s5p6440/include/mach/tick.h @@ -0,0 +1,24 @@ +/* linux/arch/arm/mach-s5p6440/include/mach/tick.h + * + * Copyright (c) 2009 Samsung Electronics Co., Ltd. + * http://www.samsung.com/ + * + * S5P6440 - Timer tick support definitions + * + * 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. +*/ + +#ifndef __ASM_ARCH_TICK_H +#define __ASM_ARCH_TICK_H __FILE__ + +/* s3c compatibility definition */ +static inline u32 s3c24xx_ostimer_pending(void) +{ + return 0; +} + +#define TICK_MAX (0xffffffff) + +#endif /* __ASM_ARCH_TICK_H */ diff --git a/arch/arm/plat-s5p/time.c b/arch/arm/plat-s5p/time.c new file mode 100644 index 0000000..a5aca07 --- /dev/null +++ b/arch/arm/plat-s5p/time.c @@ -0,0 +1,227 @@ +/* linux/arch/arm/plat-s5p/time.c + * + * Copyright (c) 2009 Samsung Electronics Co., Ltd. + * http://www.samsung.com/ + * + * S5P Timer support + * + * 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/kernel.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/platform_device.h> + +#include <asm/system.h> +#include <asm/leds.h> +#include <asm/mach-types.h> + +#include <asm/irq.h> +#include <mach/map.h> +#include <plat/regs-timer.h> +#include <mach/regs-irq.h> +#include <asm/mach/time.h> +#include <mach/tick.h> + +#include <plat/clock.h> +#include <plat/cpu.h> + +static unsigned long timer_startval; +static unsigned long timer_usec_ticks; + +#ifndef TICK_MAX +#define TICK_MAX (0xffff) +#endif + +#define TIMER_USEC_SHIFT 16 + +#define S5P6440_TCFG1_MUX4_DIV1 (0<<16) +#define S5P6440_TCFG1_MUX4_DIV2 (1<<16) +#define S5P6440_TCFG1_MUX4_DIV4 (2<<16) +#define S5P6440_TCFG1_MUX4_DIV8 (3<<16) +#define S5P6440_TCFG1_MUX4_DIV16 (4<<16) + +/* we use the shifted arithmetic to work out the ratio of timer ticks + * to usecs, as often the peripheral clock is not a nice even multiple + * of 1MHz. + * + * shift of 14 and 15 are too low for the 12MHz, 16 seems to be ok + * for the current HZ value of 200 without producing overflows. + * + * Original patch by Dimitry Andric, updated by Ben Dooks +*/ + +/* timer_mask_usec_ticks + * + * given a clock and divisor, make the value to pass into timer_ticks_to_usec + * to scale the ticks into usecs +*/ + +static inline unsigned long +timer_mask_usec_ticks(unsigned long scaler, unsigned long pclk) +{ + unsigned long den = pclk / 1000; + + return ((1000 << TIMER_USEC_SHIFT) * scaler + (den >> 1)) / den; +} + +/* timer_ticks_to_usec + * + * convert timer ticks to usec. +*/ + +static inline unsigned long timer_ticks_to_usec(unsigned long ticks) +{ + unsigned long res; + + res = ticks * timer_usec_ticks; + res += 1 << (TIMER_USEC_SHIFT - 4); /* round up slightly */ + + return res >> TIMER_USEC_SHIFT; +} + +/* note, the timer interrutps turn up in 2 places, the vic and then + * the timer block. We take the VIC as the base at the moment. +*/ + +static inline u32 s5p_ostimer_pending(void) +{ + u32 pend = __raw_readl(S5P_VA_VIC0 + VIC_RAW_STATUS); + return pend & (1 << (IRQ_TIMER4_VIC - S5P_IRQ_VIC0(0))); +} + +/* Returns microsecond since last clock interrupt. Note that interrupts + * will have been disabled by do_gettimeoffset() + * IRQs are disabled before entering here from do_gettimeofday() +*/ + +static unsigned long s5p6440_gettimeoffset(void) +{ + unsigned long tdone; + unsigned long tval; + + /* work out how many ticks have gone since last timer interrupt */ + + tval = __raw_readl(S3C2410_TCNTO(4)); + tdone = timer_startval - tval; + + /* check to see if there is an interrupt pending */ + + if (s5p_ostimer_pending()) { + + /* re-read the timer, and try and fix up for the missed + * interrupt. Note, the interrupt may go off before the + * timer has re-loaded from wrapping. + */ + + tval = __raw_readl(S3C2410_TCNTO(4)); + tdone = timer_startval - tval; + + if (tval != 0) + tdone += timer_startval; + } + + return timer_ticks_to_usec(tdone); +} + +/* IRQ handler for the timer */ + +static irqreturn_t s5p6440_timer_interrupt(int irq, void *dev_id) +{ + timer_tick(); + return IRQ_HANDLED; +} + +static struct irqaction s5p6440_timer_irq = { + .name = "S5P6440 Timer Tick", + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .handler = s5p6440_timer_interrupt, +}; + +static void s5p6440_timer_setup(void) +{ + unsigned long tcon; + unsigned long tcnt; + unsigned long tcfg1; + unsigned long tcfg0; + unsigned long pclk; + struct clk *clk; + + tcnt = TICK_MAX; /* default value for tcnt */ + + /* read the current timer configuration bits */ + + tcon = __raw_readl(S3C2410_TCON); + tcfg1 = __raw_readl(S3C2410_TCFG1); + tcfg0 = __raw_readl(S3C2410_TCFG0); + + clk = clk_get(NULL, "timers"); + if (IS_ERR(clk)) + panic("failed to get clock for system timer"); + + clk_enable(clk); + pclk = clk_get_rate(clk); + + /* configure clock tick */ + + timer_usec_ticks = timer_mask_usec_ticks(6, pclk); + + tcfg1 &= ~S3C2410_TCFG1_MUX4_MASK; + tcfg1 |= S5P6440_TCFG1_MUX4_DIV1; + tcfg0 &= ~S3C2410_TCFG_PRESCALER1_MASK; + tcfg0 |= (6) << S3C2410_TCFG_PRESCALER1_SHIFT; + tcnt = (pclk / 7) / HZ; + + /* timers reload after counting zero, so reduce the count by 1 */ + + tcnt--; + + /* check to see if timer is within 16bit range... */ + + if (tcnt > TICK_MAX) { + panic("setup_timer: HZ is too small, cannot configure timer!"); + return; + } + + __raw_writel(tcfg1, S3C2410_TCFG1); + __raw_writel(tcfg0, S3C2410_TCFG0); + + timer_startval = tcnt; + __raw_writel(tcnt, S3C2410_TCNTB(4)); + + /* ensure timer is stopped... */ + + tcon &= ~(7<<20); + tcon |= S3C2410_TCON_T4RELOAD; + tcon |= S3C2410_TCON_T4MANUALUPD; + + __raw_writel(tcon, S3C2410_TCON); + __raw_writel(tcnt, S3C2410_TCNTB(4)); + __raw_writel(tcnt, S3C2410_TCMPB(4)); + + /* start the timer running */ + + tcon |= S3C2410_TCON_T4START; + tcon &= ~S3C2410_TCON_T4MANUALUPD; + __raw_writel(tcon, S3C2410_TCON); +} + +static void __init s5p6440_timer_init(void) +{ + s5p6440_timer_setup(); + setup_irq(IRQ_TIMER4, &s5p6440_timer_irq); +} + +struct sys_timer s5p6440_timer = { + .init = s5p6440_timer_init, + .offset = s5p6440_gettimeoffset, + .resume = s5p6440_timer_setup +}; -- 1.6.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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