From bc350a91da176ae8573c0755c66f5ee1911495bc Mon Sep 17 00:00:00 2001 From: John Crispin Date: Tue, 30 Apr 2013 12:35:50 +0200 Subject: [PATCH 142/164] clocksource: MIPS: ralink: add support for systick timer found on newer ralink SoC Signed-off-by: John Crispin --- arch/mips/ralink/Kconfig | 2 + arch/mips/ralink/clk.c | 1 + drivers/clocksource/Kconfig | 6 ++ drivers/clocksource/Makefile | 1 + drivers/clocksource/cevt-rt3352.c | 162 +++++++++++++++++++++++++++++++++++++ include/linux/clocksource.h | 1 + 6 files changed, 173 insertions(+) create mode 100644 drivers/clocksource/cevt-rt3352.c --- a/arch/mips/ralink/Kconfig +++ b/arch/mips/ralink/Kconfig @@ -14,6 +14,7 @@ choice select USB_ARCH_HAS_HCD select USB_ARCH_HAS_OHCI select USB_ARCH_HAS_EHCI + select CLKEVT_RT3352 config SOC_RT3883 bool "RT3883" @@ -22,6 +23,7 @@ choice config SOC_MT7620 bool "MT7620" + select CLKEVT_RT3352 endchoice --- a/arch/mips/ralink/clk.c +++ b/arch/mips/ralink/clk.c @@ -69,4 +69,5 @@ void __init plat_time_init(void) pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000); mips_hpt_frequency = clk_get_rate(clk) / 2; clk_put(clk); + clocksource_of_init(); } --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -7,6 +7,12 @@ config CLKSRC_I8253 config CLKEVT_I8253 bool +config CLKEVT_RT3352 + bool + depends on MIPS && RALINK + select CLKSRC_OF + select CLKSRC_MMIO + config I8253_LOCK bool --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o obj-$(CONFIG_EM_TIMER_STI) += em_sti.o obj-$(CONFIG_CLKBLD_I8253) += i8253.o obj-$(CONFIG_CLKSRC_MMIO) += mmio.o +obj-$(CONFIG_CLKEVT_RT3352) += cevt-rt3352.o obj-$(CONFIG_DW_APB_TIMER) += dw_apb_timer.o obj-$(CONFIG_DW_APB_TIMER_OF) += dw_apb_timer_of.o obj-$(CONFIG_CLKSRC_NOMADIK_MTU) += nomadik-mtu.o --- /dev/null +++ b/drivers/clocksource/cevt-rt3352.c @@ -0,0 +1,162 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2013 by John Crispin + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#define SYSTICK_FREQ (50 * 1000) + +#define SYSTICK_CONFIG 0x00 +#define SYSTICK_COMPARE 0x04 +#define SYSTICK_COUNT 0x08 + +/* route systick irq to mips irq 7 instead of the r4k-timer */ +#define CFG_EXT_STK_EN 0x2 +/* enable the counter */ +#define CFG_CNT_EN 0x1 + +struct systick_device { + void __iomem *membase; + struct clock_event_device dev; + int irq_requested; + int freq_scale; +}; + +static void systick_set_clock_mode(enum clock_event_mode mode, + struct clock_event_device *evt); + +static int systick_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + struct systick_device *sdev = container_of(evt, struct systick_device, dev); + u32 count; + + count = ioread32(sdev->membase + SYSTICK_COUNT); + count = (count + delta) % SYSTICK_FREQ; + iowrite32(count + delta, sdev->membase + SYSTICK_COMPARE); + + return 0; +} + +static void systick_event_handler(struct clock_event_device *dev) +{ + /* noting to do here */ +} + +static irqreturn_t systick_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *dev = (struct clock_event_device *) dev_id; + + dev->event_handler(dev); + + return IRQ_HANDLED; +} + +static struct systick_device systick = { + .dev = { + /* cevt-r4k uses 300, make sure systick gets used if available */ + .rating = 310, + .features = CLOCK_EVT_FEAT_ONESHOT, + .set_next_event = systick_next_event, + .set_mode = systick_set_clock_mode, + .event_handler = systick_event_handler, + }, +}; + +static struct irqaction systick_irqaction = { + .handler = systick_interrupt, + .flags = IRQF_PERCPU | IRQF_TIMER, + .dev_id = &systick.dev, +}; + +/* ugly hack */ +#ifdef CONFIG_SOC_MT7620 + +#define CLK_LUT_CFG 0x40 +#define SLEEP_EN BIT(31) + +static inline void mt7620_freq_scaling(struct systick_device *sdev, int status) +{ + if (sdev->freq_scale == status) + return; + + sdev->freq_scale = status; + + pr_info("%s: %s autosleep mode\n", systick.dev.name, (status) ? ("enable") : ("disable")); + if (status) + rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) | SLEEP_EN, CLK_LUT_CFG); + else + rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) & ~SLEEP_EN, CLK_LUT_CFG); +} +#else +static inline void mt7620_freq_scaling(struct systick_device *sdev, int status) {} +#endif + +static void systick_set_clock_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + struct systick_device *sdev = container_of(evt, struct systick_device, dev); + + switch (mode) { + case CLOCK_EVT_MODE_ONESHOT: + if (!sdev->irq_requested) + setup_irq(systick.dev.irq, &systick_irqaction); + mt7620_freq_scaling(sdev, 1); + sdev->irq_requested = 1; + iowrite32(CFG_EXT_STK_EN | CFG_CNT_EN, systick.membase + SYSTICK_CONFIG); + break; + + case CLOCK_EVT_MODE_SHUTDOWN: + if (sdev->irq_requested) + free_irq(systick.dev.irq, &systick_irqaction); + mt7620_freq_scaling(sdev, 0); + sdev->irq_requested = 0; + iowrite32(0, systick.membase + SYSTICK_CONFIG); + break; + + default: + pr_err("%s: Unhandeled mips clock_mode\n", systick.dev.name); + break; + } +} + +static void __init ralink_systick_init(struct device_node *np) +{ + systick.membase = of_iomap(np, 0); + if (!systick.membase) { + pr_err("%s: of_iomap failed", np->name); + return; + } + + clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name, + SYSTICK_FREQ, 301, 16, clocksource_mmio_readl_up); + + systick_irqaction.name = np->name; + systick.dev.name = np->name; + clockevent_set_clock(&systick.dev, SYSTICK_FREQ); + systick.dev.max_delta_ns = clockevent_delta2ns(0x7fff, &systick.dev); + systick.dev.min_delta_ns = clockevent_delta2ns(0x3, &systick.dev); + systick.dev.irq = irq_of_parse_and_map(np, 0); + if (!systick.dev.irq) + panic("%s: request_irq failed", np->name); + + clockevents_register_device(&systick.dev); + + pr_info("%s: runing - mult: %d, shift: %d\n", np->name, systick.dev.mult, systick.dev.shift); +} + +CLOCKSOURCE_OF_DECLARE(systick, "ralink,cevt-systick", ralink_systick_init); --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -340,6 +340,7 @@ extern void clocksource_of_init(void); __used __section(__clksrc_of_table) \ = { .compatible = compat, .data = fn }; #else +static inline void clocksource_of_init(void) {} #define CLOCKSOURCE_OF_DECLARE(name, compat, fn) #endif