target/linux/s3c24xx/patches/0046-introduce-fiq-use-timer3-as-source.patch.patch

   1 From 26fa0c816d5e1b593128477c7e200fafe3caae18 Mon Sep 17 00:00:00 2001
   2 From: mokopatches <mokopatches@openmoko.org>
   3 Date: Fri, 25 Jul 2008 22:21:22 +0100
   4 Subject: [PATCH] introduce-fiq-use-timer3-as-source.patch
   5
   6 This makes the FIQ stuff specific to one of the timers on the
   7 s3c244x and adds the platform stuff for fiq in the gta02 init
   8
   9 Currently one sysfs node is exposed, a count of FIQ events
  10
  11 cat /sys/devices/platform/sc32440_fiq.0/fiq/count
  12
  13 From: Andy Green <andy@openmoko.com>
  14 Signed-off-by: Andy Green <andy@openmoko.com>
  15 ---
  16  arch/arm/mach-s3c2440/fiq_c_isr.c            |   56 +++++++++++++++++++++----
  17  arch/arm/mach-s3c2440/fiq_c_isr.h            |    2 +
  18  arch/arm/mach-s3c2440/mach-gta02.c           |   17 ++++++++
  19  include/asm-arm/arch-s3c2410/fiq_ipc_gta02.h |    2 +-
  20  4 files changed, 67 insertions(+), 10 deletions(-)
  21
  22 diff --git a/arch/arm/mach-s3c2440/fiq_c_isr.c b/arch/arm/mach-s3c2440/fiq_c_isr.c
  23 index 12f4527..a71a234 100644
  24 --- a/arch/arm/mach-s3c2440/fiq_c_isr.c
  25 +++ b/arch/arm/mach-s3c2440/fiq_c_isr.c
  26 @@ -18,6 +18,9 @@
  27  #include <asm/plat-s3c24xx/cpu.h>
  28  #include <asm/plat-s3c24xx/irq.h>
  29
  30 +#include <asm/arch/pwm.h>
  31 +#include <asm/plat-s3c/regs-timer.h>
  32 +
  33  /*
  34   * Major Caveats for using FIQ
  35   * ---------------------------
  36 @@ -66,6 +69,10 @@ static u8 u8aFiqStack[4096];
  37  u32 _fiq_ack_mask; /* used by isr exit define */
  38  unsigned long _fiq_count_fiqs; /* used by isr exit define */
  39  static int _fiq_irq; /* private ; irq index we were started with, or 0 */
  40 +struct s3c2410_pwm pwm_timer_fiq;
  41 +int _fiq_timer_index;
  42 +u16 _fiq_timer_divisor;
  43 +
  44
  45  /* this function must live in the monolithic kernel somewhere!  A module is
  46   * NOT good enough!
  47 @@ -110,23 +117,45 @@ static struct attribute_group s3c2440_fiq_attr_group = {
  48   * you still need to clear the source interrupt in S3C2410_INTMSK to get
  49   * anything good happening
  50   */
  51 -static void fiq_init_irq_source(int irq_index_fiq)
  52 +static int fiq_init_irq_source(int irq_index_fiq)
  53  {
  54 +       int rc = 0;
  55 +
  56         if (!irq_index_fiq) /* no interrupt */
  57 -               return;
  58 +               goto bail;
  59
  60 -       printk(KERN_INFO"Enabling FIQ using int idx %d\n",
  61 -              irq_index_fiq - S3C2410_CPUIRQ_OFFSET);
  62         local_fiq_disable();
  63
  64         _fiq_irq = irq_index_fiq;
  65         _fiq_ack_mask = 1 << (irq_index_fiq - S3C2410_CPUIRQ_OFFSET);
  66 +       timer_index = (irq_index_fiq - IRQ_TIMER0);
  67 +
  68 +       /* set up the timer to operate as a pwm device */
  69 +
  70 +       rc = s3c2410_pwm_init(&pwm_timer_fiq);
  71 +       if (rc)
  72 +               goto bail;
  73 +
  74 +       pwm_timer_fiq.timerid = PWM0 + timer_index;
  75 +       pwm_timer_fiq.prescaler = (6 - 1) / 2;
  76 +       pwm_timer_fiq.divider = S3C2410_TCFG1_MUX3_DIV2;
  77 +       /* default rate == ~32us */
  78 +       pwm_timer_fiq.counter = pwm_timer_fiq.comparer =
  79 +                                       timer_divisor = 64;
  80 +
  81 +       rc = s3c2410_pwm_enable(&pwm_timer_fiq);
  82 +       if (rc)
  83 +               goto bail;
  84 +
  85 +       s3c2410_pwm_start(&pwm_timer_fiq);
  86
  87         /* let our selected interrupt be a magic FIQ interrupt */
  88         __raw_writel(_fiq_ack_mask, S3C2410_INTMOD);
  89
  90         /* it's ready to go as soon as we unmask the source in S3C2410_INTMSK */
  91         local_fiq_enable();
  92 +bail:
  93 +       return rc;
  94  }
  95
  96
  97 @@ -139,15 +168,13 @@ static void fiq_disable_irq_source(void)
  98         _fiq_irq = 0; /* no active source interrupt now either */
  99  }
 100
 101 -/* this starts FIQ timer events... they continue until the FIQ ISR sees that
 102 - * its work is done and it turns off the timer.  After setting up the fiq_ipc
 103 - * struct with new work, you call this to start FIQ timer actions up again.
 104 - * Only the FIQ ISR decides when it is done and controls turning off the
 105 - * timer events.
 106 +/*
 107 + * fiq_kick() forces a FIQ event to happen shortly after leaving the routine
 108   */
 109  void fiq_kick(void)
 110  {
 111         unsigned long flags;
 112 +       u32 tcon;
 113
 114         /* we have to take care about FIQ because this modification is
 115          * non-atomic, FIQ could come in after the read and before the
 116 @@ -156,15 +183,24 @@ void fiq_kick(void)
 117          */
 118         local_save_flags(flags);
 119         local_fiq_disable();
 120 +       /* allow FIQs to resume */
 121         __raw_writel(__raw_readl(S3C2410_INTMSK) &
 122                      ~(1 << (_fiq_irq - S3C2410_CPUIRQ_OFFSET)),
 123                      S3C2410_INTMSK);
 124 +       tcon = __raw_readl(S3C2410_TCON) & ~S3C2410_TCON_T3START;
 125 +       /* fake the timer to a count of 1 */
 126 +       __raw_writel(1, S3C2410_TCNTB(timer_index));
 127 +       __raw_writel(tcon | S3C2410_TCON_T3MANUALUPD, S3C2410_TCON);
 128 +       __raw_writel(tcon | S3C2410_TCON_T3MANUALUPD | S3C2410_TCON_T3START,
 129 +                    S3C2410_TCON);
 130 +       __raw_writel(tcon | S3C2410_TCON_T3START, S3C2410_TCON);
 131         local_irq_restore(flags);
 132  }
 133  EXPORT_SYMBOL_GPL(fiq_kick);
 134
 135
 136
 137 +
 138  static int __init sc32440_fiq_probe(struct platform_device *pdev)
 139  {
 140         struct resource *r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 141 @@ -172,6 +208,8 @@ static int __init sc32440_fiq_probe(struct platform_device *pdev)
 142         if (!r)
 143                 return -EIO;
 144         /* configure for the interrupt we are meant to use */
 145 +       printk(KERN_INFO"Enabling FIQ using irq %d\n", r->start);
 146 +
 147         fiq_init_irq_source(r->start);
 148
 149         return sysfs_create_group(&pdev->dev.kobj, &s3c2440_fiq_attr_group);
 150 diff --git a/arch/arm/mach-s3c2440/fiq_c_isr.h b/arch/arm/mach-s3c2440/fiq_c_isr.h
 151 index f08740e..0c45eb7 100644
 152 --- a/arch/arm/mach-s3c2440/fiq_c_isr.h
 153 +++ b/arch/arm/mach-s3c2440/fiq_c_isr.h
 154 @@ -5,6 +5,8 @@
 155
 156  extern unsigned long _fiq_count_fiqs;
 157  extern u32 _fiq_ack_mask;
 158 +extern int _fiq_timer_index;
 159 +extern u16 _fiq_timer_divisor;
 160
 161  /* This CANNOT be implemented in a module -- it has to be used in code
 162   * included in the monolithic kernel
 163 diff --git a/arch/arm/mach-s3c2440/mach-gta02.c b/arch/arm/mach-s3c2440/mach-gta02.c
 164 index 0bdd0e0..cb839b2 100644
 165 --- a/arch/arm/mach-s3c2440/mach-gta02.c
 166 +++ b/arch/arm/mach-s3c2440/mach-gta02.c
 167 @@ -57,6 +57,7 @@
 168  #include <asm/irq.h>
 169  #include <asm/mach-types.h>
 170
 171 +#include <asm/arch-s3c2410/regs-irq.h>
 172  #include <asm/arch/regs-gpio.h>
 173  #include <asm/arch/regs-gpioj.h>
 174  #include <asm/arch/fb.h>
 175 @@ -336,6 +337,21 @@ struct platform_device gta02_pmu_dev = {
 176         },
 177  };
 178
 179 +/* FIQ */
 180 +
 181 +static struct resource sc32440_fiq_resources[] = {
 182 +       [0] = {
 183 +               .flags  = IORESOURCE_IRQ,
 184 +               .start  = IRQ_TIMER3,
 185 +               .end    = IRQ_TIMER3,
 186 +       },
 187 +};
 188 +
 189 +struct platform_device sc32440_fiq_device = {
 190 +       .name           = "sc32440_fiq",
 191 +       .num_resources  = 1,
 192 +       .resource       = sc32440_fiq_resources,
 193 +};
 194
 195  /* NOR Flash */
 196
 197 @@ -403,6 +419,7 @@ static struct platform_device *gta02_devices[] __initdata = {
 198         &s3c_device_nand,
 199         &s3c_device_ts,
 200         &gta02_nor_flash,
 201 +       &sc32440_fiq_device,
 202  };
 203
 204  static struct s3c2410_nand_set gta02_nand_sets[] = {
 205 diff --git a/include/asm-arm/arch-s3c2410/fiq_ipc_gta02.h b/include/asm-arm/arch-s3c2410/fiq_ipc_gta02.h
 206 index 341f2bb..6cbd8e4 100644
 207 --- a/include/asm-arm/arch-s3c2410/fiq_ipc_gta02.h
 208 +++ b/include/asm-arm/arch-s3c2410/fiq_ipc_gta02.h
 209 @@ -22,7 +22,7 @@ struct fiq_ipc {
 210
 211  /* actual definition lives in arch/arm/mach-s3c2440/fiq_c_isr.c */
 212  extern struct fiq_ipc fiq_ipc;
 213 -
 214 +extern unsigned long _fiq_count_fiqs;
 215  extern void fiq_kick(void);  /* provoke a FIQ "immediately" */
 216
 217  #endif /* _LINUX_FIQ_IPC_H */
 218 --
 219 1.5.6.3
 220