target/linux/ramips/patches-3.9/0142-clocksource-MIPS-ralink-add-support-for-systick-time.patch

   1 From bc350a91da176ae8573c0755c66f5ee1911495bc Mon Sep 17 00:00:00 2001
   2 From: John Crispin <blogic@openwrt.org>
   3 Date: Tue, 30 Apr 2013 12:35:50 +0200
   4 Subject: [PATCH 142/164] 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  include/linux/clocksource.h       |    1 +
  15  6 files changed, 173 insertions(+)
  16  create mode 100644 drivers/clocksource/cevt-rt3352.c
  17
  18 diff --git a/arch/mips/ralink/Kconfig b/arch/mips/ralink/Kconfig
  19 index 38540a4..3fe032c 100644
  20 --- a/arch/mips/ralink/Kconfig
  21 +++ b/arch/mips/ralink/Kconfig
  22 @@ -14,6 +14,7 @@ choice
  23                 select USB_ARCH_HAS_HCD
  24                 select USB_ARCH_HAS_OHCI
  25                 select USB_ARCH_HAS_EHCI
  26 +               select CLKEVT_RT3352
  27
  28         config SOC_RT3883
  29                 bool "RT3883"
  30 @@ -22,6 +23,7 @@ choice
  31
  32         config SOC_MT7620
  33                 bool "MT7620"
  34 +               select CLKEVT_RT3352
  35
  36  endchoice
  37
  38 diff --git a/arch/mips/ralink/clk.c b/arch/mips/ralink/clk.c
  39 index 8dfa22f..bba0cdf 100644
  40 --- a/arch/mips/ralink/clk.c
  41 +++ b/arch/mips/ralink/clk.c
  42 @@ -69,4 +69,5 @@ void __init plat_time_init(void)
  43         pr_info("CPU Clock: %ldMHz\n", clk_get_rate(clk) / 1000000);
  44         mips_hpt_frequency = clk_get_rate(clk) / 2;
  45         clk_put(clk);
  46 +       clocksource_of_init();
  47  }
  48 diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
  49 index e507ab7..1216c16 100644
  50 --- a/drivers/clocksource/Kconfig
  51 +++ b/drivers/clocksource/Kconfig
  52 @@ -7,6 +7,12 @@ config CLKSRC_I8253
  53  config CLKEVT_I8253
  54         bool
  55
  56 +config CLKEVT_RT3352
  57 +       bool
  58 +       depends on MIPS && RALINK
  59 +       select CLKSRC_OF
  60 +       select CLKSRC_MMIO
  61 +
  62  config I8253_LOCK
  63         bool
  64
  65 diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
  66 index 4d8283a..db47a4e 100644
  67 --- a/drivers/clocksource/Makefile
  68 +++ b/drivers/clocksource/Makefile
  69 @@ -10,6 +10,7 @@ obj-$(CONFIG_SH_TIMER_TMU)    += sh_tmu.o
  70  obj-$(CONFIG_EM_TIMER_STI)     += em_sti.o
  71  obj-$(CONFIG_CLKBLD_I8253)     += i8253.o
  72  obj-$(CONFIG_CLKSRC_MMIO)      += mmio.o
  73 +obj-$(CONFIG_CLKEVT_RT3352)    += cevt-rt3352.o
  74  obj-$(CONFIG_DW_APB_TIMER)     += dw_apb_timer.o
  75  obj-$(CONFIG_DW_APB_TIMER_OF)  += dw_apb_timer_of.o
  76  obj-$(CONFIG_CLKSRC_NOMADIK_MTU)       += nomadik-mtu.o
  77 diff --git a/drivers/clocksource/cevt-rt3352.c b/drivers/clocksource/cevt-rt3352.c
  78 new file mode 100644
  79 index 0000000..bd50edd
  80 --- /dev/null
  81 +++ b/drivers/clocksource/cevt-rt3352.c
  82 @@ -0,0 +1,162 @@
  83 +/*
  84 + * This file is subject to the terms and conditions of the GNU General Public
  85 + * License.  See the file "COPYING" in the main directory of this archive
  86 + * for more details.
  87 + *
  88 + * Copyright (C) 2013 by John Crispin <blogic@openwrt.org>
  89 + */
  90 +
  91 +#include <linux/clockchips.h>
  92 +#include <linux/clocksource.h>
  93 +#include <linux/interrupt.h>
  94 +#include <linux/reset.h>
  95 +#include <linux/init.h>
  96 +#include <linux/of.h>
  97 +#include <linux/of_irq.h>
  98 +#include <linux/of_address.h>
  99 +
 100 +#include <asm/mach-ralink/ralink_regs.h>
 101 +#include <asm/time.h>
 102 +
 103 +#define SYSTICK_FREQ   (50 * 1000)
 104 +
 105 +#define SYSTICK_CONFIG 0x00
 106 +#define SYSTICK_COMPARE        0x04
 107 +#define SYSTICK_COUNT  0x08
 108 +
 109 +/* route systick irq to mips irq 7 instead of the r4k-timer */
 110 +#define CFG_EXT_STK_EN 0x2
 111 +/* enable the counter */
 112 +#define CFG_CNT_EN     0x1
 113 +
 114 +struct systick_device {
 115 +       void __iomem *membase;
 116 +       struct clock_event_device dev;
 117 +       int irq_requested;
 118 +       int freq_scale;
 119 +};
 120 +
 121 +static void systick_set_clock_mode(enum clock_event_mode mode,
 122 +                               struct clock_event_device *evt);
 123 +
 124 +static int systick_next_event(unsigned long delta,
 125 +                               struct clock_event_device *evt)
 126 +{
 127 +       struct systick_device *sdev = container_of(evt, struct systick_device, dev);
 128 +       u32 count;
 129 +
 130 +       count = ioread32(sdev->membase + SYSTICK_COUNT);
 131 +       count = (count + delta) % SYSTICK_FREQ;
 132 +       iowrite32(count + delta, sdev->membase + SYSTICK_COMPARE);
 133 +
 134 +       return 0;
 135 +}
 136 +
 137 +static void systick_event_handler(struct clock_event_device *dev)
 138 +{
 139 +       /* noting to do here */
 140 +}
 141 +
 142 +static irqreturn_t systick_interrupt(int irq, void *dev_id)
 143 +{
 144 +       struct clock_event_device *dev = (struct clock_event_device *) dev_id;
 145 +
 146 +       dev->event_handler(dev);
 147 +
 148 +       return IRQ_HANDLED;
 149 +}
 150 +
 151 +static struct systick_device systick = {
 152 +       .dev = {
 153 +               /* cevt-r4k uses 300, make sure systick gets used if available */
 154 +               .rating         = 310,
 155 +               .features       = CLOCK_EVT_FEAT_ONESHOT,
 156 +               .set_next_event = systick_next_event,
 157 +               .set_mode       = systick_set_clock_mode,
 158 +               .event_handler  = systick_event_handler,
 159 +       },
 160 +};
 161 +
 162 +static struct irqaction systick_irqaction = {
 163 +       .handler = systick_interrupt,
 164 +       .flags = IRQF_PERCPU | IRQF_TIMER,
 165 +       .dev_id = &systick.dev,
 166 +};
 167 +
 168 +/* ugly hack */
 169 +#ifdef CONFIG_SOC_MT7620
 170 +
 171 +#define CLK_LUT_CFG    0x40
 172 +#define SLEEP_EN       BIT(31)
 173 +
 174 +static inline void mt7620_freq_scaling(struct systick_device *sdev, int status)
 175 +{
 176 +       if (sdev->freq_scale == status)
 177 +               return;
 178 +
 179 +       sdev->freq_scale = status;
 180 +
 181 +       pr_info("%s: %s autosleep mode\n", systick.dev.name, (status) ? ("enable") : ("disable"));
 182 +       if (status)
 183 +               rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) | SLEEP_EN, CLK_LUT_CFG);
 184 +       else
 185 +               rt_sysc_w32(rt_sysc_r32(CLK_LUT_CFG) & ~SLEEP_EN, CLK_LUT_CFG);
 186 +}
 187 +#else
 188 +static inline void mt7620_freq_scaling(struct systick_device *sdev, int status) {}
 189 +#endif
 190 +
 191 +static void systick_set_clock_mode(enum clock_event_mode mode,
 192 +                               struct clock_event_device *evt)
 193 +{
 194 +       struct systick_device *sdev = container_of(evt, struct systick_device, dev);
 195 +
 196 +       switch (mode) {
 197 +       case CLOCK_EVT_MODE_ONESHOT:
 198 +               if (!sdev->irq_requested)
 199 +                       setup_irq(systick.dev.irq, &systick_irqaction);
 200 +               mt7620_freq_scaling(sdev, 1);
 201 +               sdev->irq_requested = 1;
 202 +               iowrite32(CFG_EXT_STK_EN | CFG_CNT_EN, systick.membase + SYSTICK_CONFIG);
 203 +               break;
 204 +
 205 +       case CLOCK_EVT_MODE_SHUTDOWN:
 206 +               if (sdev->irq_requested)
 207 +                       free_irq(systick.dev.irq, &systick_irqaction);
 208 +               mt7620_freq_scaling(sdev, 0);
 209 +               sdev->irq_requested = 0;
 210 +               iowrite32(0, systick.membase + SYSTICK_CONFIG);
 211 +               break;
 212 +
 213 +       default:
 214 +               pr_err("%s: Unhandeled mips clock_mode\n", systick.dev.name);
 215 +               break;
 216 +       }
 217 +}
 218 +
 219 +static void __init ralink_systick_init(struct device_node *np)
 220 +{
 221 +       systick.membase = of_iomap(np, 0);
 222 +       if (!systick.membase) {
 223 +               pr_err("%s: of_iomap failed", np->name);
 224 +               return;
 225 +       }
 226 +
 227 +       clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
 228 +                       SYSTICK_FREQ, 301, 16, clocksource_mmio_readl_up);
 229 +
 230 +       systick_irqaction.name = np->name;
 231 +       systick.dev.name = np->name;
 232 +       clockevent_set_clock(&systick.dev, SYSTICK_FREQ);
 233 +       systick.dev.max_delta_ns = clockevent_delta2ns(0x7fff, &systick.dev);
 234 +       systick.dev.min_delta_ns = clockevent_delta2ns(0x3, &systick.dev);
 235 +       systick.dev.irq = irq_of_parse_and_map(np, 0);
 236 +       if (!systick.dev.irq)
 237 +               panic("%s: request_irq failed", np->name);
 238 +
 239 +       clockevents_register_device(&systick.dev);
 240 +
 241 +       pr_info("%s: runing - mult: %d, shift: %d\n", np->name, systick.dev.mult, systick.dev.shift);
 242 +}
 243 +
 244 +CLOCKSOURCE_OF_DECLARE(systick, "ralink,cevt-systick", ralink_systick_init);
 245 diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
 246 index 27cfda4..08ed5e1 100644
 247 --- a/include/linux/clocksource.h
 248 +++ b/include/linux/clocksource.h
 249 @@ -340,6 +340,7 @@ extern void clocksource_of_init(void);
 250                 __used __section(__clksrc_of_table)                     \
 251                  = { .compatible = compat, .data = fn };
 252  #else
 253 +static inline void clocksource_of_init(void) {}
 254  #define CLOCKSOURCE_OF_DECLARE(name, compat, fn)
 255  #endif
 256
 257 --
 258 1.7.10.4
 259