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

Jaehoon Chung jh80.chung at samsung.com
Fri Dec 21 10:18:10 CET 2012


On 12/21/2012 02:16 PM, Amarendra Reddy wrote:
> Hi Simon,
> 
> Thanks for your review comments.
> Please find the responses below.
> 
> Thanks & Regards
> Amarendra Reddy
> 
> On 20 December 2012 07:53, Simon Glass <sjg at chromium.org> wrote:
> 
>> 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?
>>  Oops.. sorry. I will put the commit msg.
>>
>>> ---
>>
>>  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.
>>
>> In case of non-dt support, these two values are written into respective
> clock selection register-CLKSEL, to select the clock for MMC-channel0 and
> MMC-channel2.
> Will move clock setting into clock.c and the #defines will be moved into
> include/asm/arch/clk.h.
I didn't want to move into clk.h. Why do you move there?
It is related with CLKSEL register into DesignWare IP.

> 
>>
>>>
>>>  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.
>>
>> I think we need support operation without CONFIG_OF_CONTROL atleast untill
> the entire FDT is formed.
> Hence I will implement it as per your suggestion.
> 
> 
>> Also please can you briefly comment non-trivial functions?
>>  OK.
>>
>>>  {
>>>         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.
>>
>> OK.
>>
> 
> 
>>> +
>>> +               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?
>>  Ok will change accordingly.
>>
>>> +
>>> +               /* 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?
>> Will remove it.
>>
>>>
>>>  #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
>>
>> _______________________________________________
>> U-Boot mailing list
>> U-Boot at lists.denx.de
>> http://lists.denx.de/mailman/listinfo/u-boot
>>
>>
> 
> 
> 
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