[U-Boot] [PATCH 4/9] EXYNOS5: DWMMC: Added dt support for DWMMC

Simon Glass sjg at chromium.org
Thu Dec 20 03:23:14 CET 2012


Hi Amar,

On Mon, Dec 17, 2012 at 3:19 AM, Amar <amarendra.xt at samsung.com> wrote:

> Signed-off-by: Amar <amarendra.xt at samsung.com>
>

Good to see this patch! Please can you add a short commit message?


> ---

 arch/arm/include/asm/arch-exynos/dwmmc.h |    4 +
>  drivers/mmc/exynos_dw_mmc.c              |  117
> ++++++++++++++++++++++++++++--
>  include/dwmmc.h                          |    4 +
>  3 files changed, 119 insertions(+), 6 deletions(-)
>
> diff --git a/arch/arm/include/asm/arch-exynos/dwmmc.h
> b/arch/arm/include/asm/arch-exynos/dwmmc.h
> index 8acdf9b..92352df 100644
> --- a/arch/arm/include/asm/arch-exynos/dwmmc.h
> +++ b/arch/arm/include/asm/arch-exynos/dwmmc.h
> @@ -27,6 +27,9 @@
>  #define DWMCI_SET_DRV_CLK(x)   ((x) << 16)
>  #define DWMCI_SET_DIV_RATIO(x) ((x) << 24)
>
> +#ifdef CONFIG_OF_CONTROL
> +unsigned int exynos_dwmmc_init(const void *blob);
> +#else
>  int exynos_dwmci_init(u32 regbase, int bus_width, int index);
>
>  static inline unsigned int exynos_dwmmc_init(int index, int bus_width)
> @@ -34,3 +37,4 @@ static inline unsigned int exynos_dwmmc_init(int index,
> int bus_width)
>         unsigned int base = samsung_get_base_mmc() + (0x10000 * index);
>         return exynos_dwmci_init(base, bus_width, index);
>  }
> +#endif
> diff --git a/drivers/mmc/exynos_dw_mmc.c b/drivers/mmc/exynos_dw_mmc.c
> index 72a31b7..3b3e3e5 100644
> --- a/drivers/mmc/exynos_dw_mmc.c
> +++ b/drivers/mmc/exynos_dw_mmc.c
> @@ -19,23 +19,38 @@
>   */
>
>  #include <common.h>
> -#include <malloc.h>
>  #include <dwmmc.h>
> +#include <fdtdec.h>
> +#include <libfdt.h>
> +#include <malloc.h>
>  #include <asm/arch/dwmmc.h>
>  #include <asm/arch/clk.h>
> +#include <asm/arch/pinmux.h>
> +
> +#define        DWMMC_MAX_CH_NUM                4
> +#define        DWMMC_MAX_FREQ                  52000000
> +#define        DWMMC_MIN_FREQ                  400000
> +#define        DWMMC_MMC0_CLKSEL_VAL           0x03030001
> +#define        DWMMC_MMC2_CLKSEL_VAL           0x03020001
>

What do these last two values mean? I think clock setting should be done in
clock.c, not here.


>
>  static char *EXYNOS_NAME = "EXYNOS DWMMC";
>
>  static void exynos_dwmci_clksel(struct dwmci_host *host)
>  {
> -       u32 val;
> -       val = DWMCI_SET_SAMPLE_CLK(DWMCI_SHIFT_0) |
> -               DWMCI_SET_DRV_CLK(DWMCI_SHIFT_0) | DWMCI_SET_DIV_RATIO(0);
> +       dwmci_writel(host, DWMCI_CLKSEL, host->clksel_val);
> +}
>
> -       dwmci_writel(host, DWMCI_CLKSEL, val);
> +unsigned int exynos_dwmci_get_clk(int dev_index)
> +{
> +       return get_mmc_clk(dev_index);
>  }
>
> +#ifdef CONFIG_OF_CONTROL
> +static int exynos_dwmci_init(u32 regbase, int bus_width,
> +                                       int index, u32 *timing)
> +#else
>  int exynos_dwmci_init(u32 regbase, int bus_width, int index)
> +#endif
>

I'm really not keen on having the same function with different signatures.
My first question is whether we need to support operation without
CONFIG_OF_CONTROL. If so, I suggest having an init routine that takes an
FDT blob as a parameter, and a separate add_port function which can be
called by non-FDT-enabled board files. The init routine will call the
add_port function for each port it finds in the FDT.

Also please can you briefly comment non-trivial functions?


>  {
>         struct dwmci_host *host = NULL;
>         host = malloc(sizeof(struct dwmci_host));
> @@ -44,14 +59,104 @@ int exynos_dwmci_init(u32 regbase, int bus_width, int
> index)
>                 return 1;
>         }
>
> +       /* set the clock divisor - clk_div_fsys for mmc */
> +       if (exynos5_mmc_set_clk_div(index)) {
> +               debug("mmc clock div set failed\n");
> +               return -1;
> +       }
> +
>         host->name = EXYNOS_NAME;
>         host->ioaddr = (void *)regbase;
>         host->buswidth = bus_width;
> +#ifdef CONFIG_OF_CONTROL
> +       host->clksel_val = (DWMCI_SET_SAMPLE_CLK(timing[0]) |
> +                               DWMCI_SET_DRV_CLK(timing[1]) |
> +                               DWMCI_SET_DIV_RATIO(timing[2]));
> +#else
> +       if (0 == index)
> +               host->clksel_val = DWMMC_MMC0_CLKSEL_VAL;
> +       if (2 == index)
> +               host->clksel_val = DWMMC_MMC2_CLKSEL_VAL;
> +#endif
>         host->clksel = exynos_dwmci_clksel;
>         host->dev_index = index;
> +       host->mmc_clk = exynos_dwmci_get_clk;
>
> -       add_dwmci(host, 52000000, 400000);
> +       add_dwmci(host, DWMMC_MAX_FREQ, DWMMC_MIN_FREQ);
>
>         return 0;
>  }
>
> +#ifdef CONFIG_OF_CONTROL
> +unsigned int exynos_dwmmc_init(const void *blob)
> +{
> +       u32 base;
> +       int index, bus_width;
> +       int node_list[DWMMC_MAX_CH_NUM];
> +       int err = 0;
> +       int dev_id, flag;
> +       u32 timing[3];
> +       int count, i;
> +
> +       count = fdtdec_find_aliases_for_id(blob, "dwmmc",
> +                               COMPAT_SAMSUNG_EXYNOS5_DWMMC, node_list,
> +                               DWMMC_MAX_CH_NUM);
> +
> +       for (i = 0; i < count; i++) {
> +               int node = node_list[i];
> +
> +               if (node <= 0)
> +                       continue;
> +
> +               /* config pinmux for each mmc channel */
> +               dev_id = pinmux_decode_periph_id(blob, node);
> +               if (dev_id == PERIPH_ID_SDMMC0)
> +                       flag = PINMUX_FLAG_8BIT_MODE;
> +               else
> +                       flag = PINMUX_FLAG_NONE;
>

This should be decoded from the FDT - e.g. fdtdec_get_int(blob, node,
"samsung,width") == 8.


> +
> +               err = exynos_pinmux_config(dev_id, flag);
> +               if (err) {
> +                       debug("DWMMC not configured\n");
> +                       return err;
> +               }
> +
> +               /* Get the base address from the device node */
> +               base = fdtdec_get_addr(blob, node, "reg");
> +               if (!base) {
> +                       debug("DWMMC: Can't get base address\n");
> +                       return -1;
> +               }
> +
> +               /* Get the channel index from the device node */
> +               index = fdtdec_get_int(blob, node, "index", 0);
> +               if (index < 0) {
> +                       debug("DWMMC: Can't get channel index\n");
> +                       return -1;
> +               }
>

What is this needed for? Doesn't the reg address tell you everything you
need here?


> +
> +               /* Get the bus width from the device node */
> +               bus_width = fdtdec_get_int(blob, node, "bus-width", 0);
> +               if (bus_width < 0) {
> +                       debug("DWMMC: Can't get bus-width\n");
> +                       return -1;
> +               }

+
> +               err = fdtdec_get_int_array(blob, node, "timing",
> +                                       timing, 3);
> +               if (err) {
> +                       debug("Can't get sdr-timings for divider\n");
> +                       return -1;
> +               }
> +
> +               err =  exynos_dwmci_init(base, bus_width,
> +                                               index, timing);
> +               if (err) {
> +                       debug("Can't do dwmci init\n");
> +                       return -1;
> +               }
> +       }
> +
> +       return 0;
> +}
> +#endif
> diff --git a/include/dwmmc.h b/include/dwmmc.h
> index c8b1d40..4a42849 100644
> --- a/include/dwmmc.h
> +++ b/include/dwmmc.h
> @@ -123,6 +123,9 @@
>  #define MSIZE(x)               ((x) << 28)
>  #define RX_WMARK(x)            ((x) << 16)
>  #define TX_WMARK(x)            (x)
> +#define RX_WMARK_SHIFT         16
> +#define RX_WMARK_MASK          (0xfff << RX_WMARK_SHIFT)
> +
>

Extra blank line here?


>
>  #define DWMCI_IDMAC_OWN                (1 << 31)
>  #define DWMCI_IDMAC_CH         (1 << 4)
> @@ -144,6 +147,7 @@ struct dwmci_host {
>         unsigned int bus_hz;
>         int dev_index;
>         int buswidth;
> +       u32 clksel_val;
>         u32 fifoth_val;
>         struct mmc *mmc;
>
> --
> 1.7.0.4
>
>
Regards,
Simon


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