target/linux/s3c24xx/patches-2.6.24/1323-GTA01-use-slow-SD-clock-when-gps-on.patch.patch

   1 From d944934bbddc281938fb1905a69e35c0581937c2 Mon Sep 17 00:00:00 2001
   2 From: Mike Westerhof <mwester@dls.net>
   3 Date: Thu, 13 Nov 2008 20:39:36 +0000
   4 Subject: [PATCH] GTA01-use-slow-SD-clock-when-gps-on.patch
   5
   6 This patch implements Andy Green's SD clock slow-down code
   7 for the GTA01 device.
   8
   9 Signed-off-by: Mike Westerhof <mwester@dls.net>
  10 ---
  11  arch/arm/mach-s3c2410/mach-gta01.c |    8 ++++++
  12  drivers/mmc/host/s3cmci.c          |   43 ++++++++++++++++++++++++++++++++++-
  13  drivers/mmc/host/s3cmci.h          |    1 +
  14  include/asm-arm/arch-s3c2410/mci.h |    1 +
  15  4 files changed, 51 insertions(+), 2 deletions(-)
  16
  17 diff --git a/arch/arm/mach-s3c2410/mach-gta01.c b/arch/arm/mach-s3c2410/mach-gta01.c
  18 index a364b76..c0817dc 100644
  19 --- a/arch/arm/mach-s3c2410/mach-gta01.c
  20 +++ b/arch/arm/mach-s3c2410/mach-gta01.c
  21 @@ -75,6 +75,8 @@
  22  #include <asm/plat-s3c24xx/neo1973.h>
  23  #include <asm/arch-s3c2410/neo1973-pm-gsm.h>
  24
  25 +#include "../plat-s3c24xx/neo1973_pm_gps.h"
  26 +
  27  #include <linux/jbt6k74.h>
  28
  29  static struct map_desc gta01_iodesc[] __initdata = {
  30 @@ -432,9 +434,15 @@ static void gta01_mmc_set_power(unsigned char power_mode, unsigned short vdd)
  31         }
  32  }
  33
  34 +static int gta01_mmc_use_slow(void)
  35 +{
  36 +       return neo1973_pm_gps_is_on();
  37 +}
  38 +
  39  static struct s3c24xx_mci_pdata gta01_mmc_cfg = {
  40         .gpio_detect    = GTA01_GPIO_nSD_DETECT,
  41         .set_power      = &gta01_mmc_set_power,
  42 +       .use_slow       = &gta01_mmc_use_slow,
  43         .ocr_avail      = MMC_VDD_165_195|MMC_VDD_20_21|
  44                           MMC_VDD_21_22|MMC_VDD_22_23|MMC_VDD_23_24|
  45                           MMC_VDD_24_25|MMC_VDD_25_26|MMC_VDD_26_27|
  46 diff --git a/drivers/mmc/host/s3cmci.c b/drivers/mmc/host/s3cmci.c
  47 index 8f88721..87d24b2 100644
  48 --- a/drivers/mmc/host/s3cmci.c
  49 +++ b/drivers/mmc/host/s3cmci.c
  50 @@ -59,6 +59,23 @@ module_param(sd_max_clk, int, 0644);
  51  static int sd_idleclk;  /* disallow idle clock by default */
  52  module_param(sd_idleclk, int, 0644);
  53
  54 +/*
  55 + * Slow SD clock rate
  56 + *
  57 + * you can override this on kernel commandline using
  58 + *
  59 + *  s3cmci.sd_slow_ratio=8
  60 + *
  61 + * for example.
  62 + *
  63 + * A platform callback is used to decide effective clock rate.  If not
  64 + * defined, then the max is used, if defined and the callback returns
  65 + * nonzero, the rate is divided by this factor.
  66 + */
  67 +
  68 +static int sd_slow_ratio = 8;
  69 +module_param(sd_slow_ratio, int, 0644);
  70 +
  71  /* used to stash real idleclk state in suspend: we force it to run in there */
  72  static int suspend_sd_idleclk;
  73
  74 @@ -252,7 +269,7 @@ static inline void do_pio_read(struct s3cmci_host *host)
  75         void __iomem *from_ptr;
  76
  77         /* write real prescaler to host, it might be set slow to fix */
  78 -       writel(host->prescaler, host->base + S3C2410_SDIPRE);
  79 +       writel(host->sdipre, host->base + S3C2410_SDIPRE);
  80
  81         from_ptr = host->base + host->sdidata;
  82
  83 @@ -755,7 +772,7 @@ static void finalize_request(struct s3cmci_host *host)
  84         cmd->resp[3] = readl(host->base + S3C2410_SDIRSP3);
  85
  86         /* reset clock speed, as it could still be set low for */
  87 -       writel(host->prescaler, host->base + S3C2410_SDIPRE);
  88 +       writel(host->sdipre, host->base + S3C2410_SDIPRE);
  89
  90         if (cmd->error)
  91                 debug_as_failure = 1;
  92 @@ -1032,6 +1049,7 @@ static void s3cmci_send_request(struct mmc_host *mmc)
  93         struct s3cmci_host *host = mmc_priv(mmc);
  94         struct mmc_request *mrq = host->mrq;
  95         struct mmc_command *cmd = host->cmd_is_stop?mrq->stop:mrq->cmd;
  96 +       int pre;
  97
  98         host->ccnt++;
  99  #ifdef CONFIG_MMC_DEBUG
 100 @@ -1073,6 +1091,26 @@ static void s3cmci_send_request(struct mmc_host *mmc)
 101
 102         }
 103
 104 +       /* establish the correct prescaler depending on the sd_slow_ratio */
 105 +
 106 +       if ((sd_slow_ratio > 1) &&
 107 +           host->pdata->use_slow && (host->pdata->use_slow)()) {
 108 +               /* compute the slower speed */
 109 +               pre = host->prescaler * sd_slow_ratio;
 110 +               if (pre > 255)
 111 +                       pre = 255;
 112 +       } else {
 113 +               /* use the normal speed */
 114 +               pre = host->prescaler;
 115 +       }
 116 +
 117 +       if (host->sdipre != pre) {
 118 +               dbg(host, dbg_conf, "prescaler changed: %d -> %d\n",
 119 +                   (int)host->sdipre, pre);
 120 +               host->sdipre = pre;
 121 +               writel(host->sdipre, host->base + S3C2410_SDIPRE);
 122 +       }
 123 +
 124         __s3cmci_enable_clock(host);
 125         s3cmci_send_command(host, cmd);
 126         enable_irq(host->irq);
 127 @@ -1138,6 +1176,7 @@ static void s3cmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 128         if (mci_psc > 255)
 129                 mci_psc = 255;
 130         host->prescaler = mci_psc;
 131 +       host->sdipre = mci_psc;
 132
 133         writel(host->prescaler, host->base + S3C2410_SDIPRE);
 134
 135 diff --git a/drivers/mmc/host/s3cmci.h b/drivers/mmc/host/s3cmci.h
 136 index 9644b45..11974ff 100644
 137 --- a/drivers/mmc/host/s3cmci.h
 138 +++ b/drivers/mmc/host/s3cmci.h
 139 @@ -32,6 +32,7 @@ struct s3cmci_host {
 140         unsigned long           clk_div;
 141         unsigned long           real_rate;
 142         u8                      prescaler;
 143 +       u8                      sdipre;
 144
 145         int                     is2440;
 146         unsigned                sdiimsk;
 147 diff --git a/include/asm-arm/arch-s3c2410/mci.h b/include/asm-arm/arch-s3c2410/mci.h
 148 index 24e6cd1..f087229 100644
 149 --- a/include/asm-arm/arch-s3c2410/mci.h
 150 +++ b/include/asm-arm/arch-s3c2410/mci.h
 151 @@ -8,6 +8,7 @@ struct s3c24xx_mci_pdata {
 152         unsigned int    do_dma;
 153         void            (*set_power)(unsigned char power_mode,
 154                                      unsigned short vdd);
 155 +       int             (*use_slow)(void);
 156  };
 157
 158  #endif /* _ARCH_NCI_H */
 159 --
 160 1.5.6.5
 161