target/linux/ramips/patches-3.10/0022-clocksource-MIPS-ralink-add-support-for-systick-time.patch

   1 From 10cb446ac01be52c49b5143c8601524bc4f53051 Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Sun, 14 Jul 2013 23:11:05 +0200
   4 Subject: [PATCH 22/33] clocksource: MIPS: ralink: add support for systick
   5  timer found on newer ralink SoC
   6
   7 Signed-off-by: John Crispin <blogic@openwrt.org>
   8 ---
   9  arch/mips/ralink/Kconfig          |    2 +
  10  arch/mips/ralink/clk.c            |    1 +
  11  drivers/clocksource/Kconfig       |    6 ++
  12  drivers/clocksource/Makefile      |    1 +
  13  drivers/clocksource/cevt-rt3352.c |  162 +++++++++++++++++++++++++++++++++++++
  14  5 files changed, 172 insertions(+)
  15  create mode 100644 drivers/clocksource/cevt-rt3352.c
  16
  17 diff --git a/arch/mips/ralink/Kconfig b/arch/mips/ralink/Kconfig
  18 index 8f49ed7..f5d97b8 100644
  19 --- a/arch/mips/ralink/Kconfig
  20 +++ b/arch/mips/ralink/Kconfig
  21 @@ -15,6 +15,7 @@ choice
  22                 select USB_ARCH_HAS_HCD
  23                 select USB_ARCH_HAS_OHCI
  24                 select USB_ARCH_HAS_EHCI
  25 +               select CLKEVT_RT3352
  26
  27         config SOC_RT3883
  28                 bool "RT3883"
  29 @@ -27,6 +28,7 @@ choice
  30                 select USB_ARCH_HAS_OHCI
  31                 select USB_ARCH_HAS_EHCI
  32                 select HW_HAS_PCI
  33 +               select CLKEVT_RT3352
  34
  35  endchoice
  36
  37 diff --git a/arch/mips/ralink/clk.c b/arch/mips/ralink/clk.c
  38 index 8dfa22f..bba0cdf 100644
  39 --- a/arch/mips/ralink/clk.c
  40 +++ b/arch/mips/ralink/clk.c
  41 @@ -69,4 +69,5 @@ void __init plat_time_init(void)
  42         pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000);
  43         mips_hpt_frequency = clk_get_rate(clk) / 2;
  44         clk_put(clk);
  45 +       clocksource_of_init();
  46  }
  47 diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
  48 index f151c6c..0e58a49 100644
  49 --- a/drivers/clocksource/Kconfig
  50 +++ b/drivers/clocksource/Kconfig
  51 @@ -7,6 +7,12 @@ config CLKSRC_I8253
  52  config CLKEVT_I8253
  53         bool
  54
  55 +config CLKEVT_RT3352
  56 +       bool
  57 +       depends on MIPS && RALINK
  58 +       select CLKSRC_OF
  59 +       select CLKSRC_MMIO
  60 +
  61  config I8253_LOCK
  62         bool
  63
  64 diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
  65 index 8d979c7..423a2ef 100644
  66 --- a/drivers/clocksource/Makefile
  67 +++ b/drivers/clocksource/Makefile
  68 @@ -10,6 +10,7 @@ obj-$(CONFIG_SH_TIMER_TMU)    += sh_tmu.o
  69  obj-$(CONFIG_EM_TIMER_STI)     += em_sti.o
  70  obj-$(CONFIG_CLKBLD_I8253)     += i8253.o
  71  obj-$(CONFIG_CLKSRC_MMIO)      += mmio.o
  72 +obj-$(CONFIG_CLKEVT_RT3352)    += cevt-rt3352.o
  73  obj-$(CONFIG_DW_APB_TIMER)     += dw_apb_timer.o
  74  obj-$(CONFIG_DW_APB_TIMER_OF)  += dw_apb_timer_of.o
  75  obj-$(CONFIG_CLKSRC_NOMADIK_MTU)       += nomadik-mtu.o
  76 diff --git a/drivers/clocksource/cevt-rt3352.c b/drivers/clocksource/cevt-rt3352.c
  77 new file mode 100644
  78 index 0000000..bd50edd
  79 --- /dev/null
  80 +++ b/drivers/clocksource/cevt-rt3352.c
  81 @@ -0,0 +1,162 @@
  82 +/*
  83 + * This file is subject to the terms and conditions of the GNU General Public
  84 + * License.  See the file "COPYING" in the main directory of this archive
  85 + * for more details.
  86 + *
  87 + * Copyright (C) 2013 by John Crispin <blogic@openwrt.org>
  88 + */
  89 +
  90 +#include <linux/clockchips.h>
  91 +#include <linux/clocksource.h>
  92 +#include <linux/interrupt.h>
  93 +#include <linux/reset.h>
  94 +#include <linux/init.h>
  95 +#include <linux/of.h>
  96 +#include <linux/of_irq.h>
  97 +#include <linux/of_address.h>
  98 +
  99 +#include <asm/mach-ralink/ralink_regs.h>
 100 +#include <asm/time.h>
 101 +
 102 +#define SYSTICK_FREQ   (50 * 1000)
 103 +
 104 +#define SYSTICK_CONFIG 0x00
 105 +#define SYSTICK_COMPARE        0x04
 106 +#define SYSTICK_COUNT  0x08
 107 +
 108 +/* route systick irq to mips irq 7 instead of the r4k-timer */
 109 +#define CFG_EXT_STK_EN 0x2
 110 +/* enable the counter */
 111 +#define CFG_CNT_EN     0x1
 112 +
 113 +struct systick_device {
 114 +       void __iomem *membase;
 115 +       struct clock_event_device dev;
 116 +       int irq_requested;
 117 +       int freq_scale;
 118 +};
 119 +
 120 +static void systick_set_clock_mode(enum clock_event_mode mode,
 121 +                               struct clock_event_device *evt);
 122 +
 123 +static int systick_next_event(unsigned long delta,
 124 +                               struct clock_event_device *evt)
 125 +{
 126 +       struct systick_device *sdev = container_of(evt, struct systick_device, dev);
 127 +       u32 count;
 128 +
 129 +       count = ioread32(sdev->membase + SYSTICK_COUNT);
 130 +       count = (count + delta) % SYSTICK_FREQ;
 131 +       iowrite32(count + delta, sdev->membase + SYSTICK_COMPARE);
 132 +
 133 +       return 0;
 134 +}
 135 +
 136 +static void systick_event_handler(struct clock_event_device *dev)
 137 +{
 138 +       /* noting to do here */
 139 +}
 140 +
 141 +static irqreturn_t systick_interrupt(int irq, void *dev_id)
 142 +{
 143 +       struct clock_event_device *dev = (struct clock_event_device *) dev_id;
 144 +
 145 +       dev->event_handler(dev);
 146 +
 147 +       return IRQ_HANDLED;
 148 +}
 149 +
 150 +static struct systick_device systick = {
 151 +       .dev = {
 152 +               /* cevt-r4k uses 300, make sure systick gets used if available */
 153 +               .rating         = 310,
 154 +               .features       = CLOCK_EVT_FEAT_ONESHOT,
 155 +               .set_next_event = systick_next_event,
 156 +               .set_mode       = systick_set_clock_mode,
 157 +               .event_handler  = systick_event_handler,
 158 +       },
 159 +};
 160 +
 161 +static struct irqaction systick_irqaction = {
 162 +       .handler = systick_interrupt,
 163 +       .flags = IRQF_PERCPU | IRQF_TIMER,
 164 +       .dev_id = &systick.dev,
 165 +};
 166 +
 167 +/* ugly hack */
 168 +#ifdef CONFIG_SOC_MT7620
 169 +
 170 +#define CLK_LUT_CFG    0x40
 171 +#define SLEEP_EN       BIT(31)
 172 +
 173 +static inline void mt7620_freq_scaling(struct systick_device *sdev, int status)
 174 +{
 175 +       if (sdev->freq_scale == status)
 176 +               return;
 177 +
 178 +       sdev->freq_scale = status;
 179 +
 180 +       pr_info("%s: %s autosleep mode\n", systick.dev.name, (status) ? ("enable") : ("disable"));
 181 +       if (status)
 182 +               rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) | SLEEP_EN, CLK_LUT_CFG);
 183 +       else
 184 +               rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) & ~SLEEP_EN, CLK_LUT_CFG);
 185 +}
 186 +#else
 187 +static inline void mt7620_freq_scaling(struct systick_device *sdev, int status) {}
 188 +#endif
 189 +
 190 +static void systick_set_clock_mode(enum clock_event_mode mode,
 191 +                               struct clock_event_device *evt)
 192 +{
 193 +       struct systick_device *sdev = container_of(evt, struct systick_device, dev);
 194 +
 195 +       switch (mode) {
 196 +       case CLOCK_EVT_MODE_ONESHOT:
 197 +               if (!sdev->irq_requested)
 198 +                       setup_irq(systick.dev.irq, &systick_irqaction);
 199 +               mt7620_freq_scaling(sdev, 1);
 200 +               sdev->irq_requested = 1;
 201 +               iowrite32(CFG_EXT_STK_EN | CFG_CNT_EN, systick.membase + SYSTICK_CONFIG);
 202 +               break;
 203 +
 204 +       case CLOCK_EVT_MODE_SHUTDOWN:
 205 +               if (sdev->irq_requested)
 206 +                       free_irq(systick.dev.irq, &systick_irqaction);
 207 +               mt7620_freq_scaling(sdev, 0);
 208 +               sdev->irq_requested = 0;
 209 +               iowrite32(0, systick.membase + SYSTICK_CONFIG);
 210 +               break;
 211 +
 212 +       default:
 213 +               pr_err("%s: Unhandeled mips clock_mode\n", systick.dev.name);
 214 +               break;
 215 +       }
 216 +}
 217 +
 218 +static void __init ralink_systick_init(struct device_node *np)
 219 +{
 220 +       systick.membase = of_iomap(np, 0);
 221 +       if (!systick.membase) {
 222 +               pr_err("%s: of_iomap failed", np->name);
 223 +               return;
 224 +       }
 225 +
 226 +       clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
 227 +                       SYSTICK_FREQ, 301, 16, clocksource_mmio_readl_up);
 228 +
 229 +       systick_irqaction.name = np->name;
 230 +       systick.dev.name = np->name;
 231 +       clockevent_set_clock(&systick.dev, SYSTICK_FREQ);
 232 +       systick.dev.max_delta_ns = clockevent_delta2ns(0x7fff, &systick.dev);
 233 +       systick.dev.min_delta_ns = clockevent_delta2ns(0x3, &systick.dev);
 234 +       systick.dev.irq = irq_of_parse_and_map(np, 0);
 235 +       if (!systick.dev.irq)
 236 +               panic("%s: request_irq failed", np->name);
 237 +
 238 +       clockevents_register_device(&systick.dev);
 239 +
 240 +       pr_info("%s: runing - mult: %d, shift: %d\n", np->name, systick.dev.mult, systick.dev.shift);
 241 +}
 242 +
 243 +CLOCKSOURCE_OF_DECLARE(systick, "ralink,cevt-systick", ralink_systick_init);
 244 --
 245 1.7.10.4
 246