[U-Boot] [PATCH V8 4/9] EXYNOS5: DWMMC: Added FDT support for DWMMC

Jaehoon Chung jh80.chung at samsung.com
Fri Apr 12 13:20:26 CEST 2013


On 04/10/2013 03:13 PM, Amarendra Reddy wrote:
> Hi Jaehoon,
> 
> Please find my responses below.
> 
> Thanks & Regards
> Amarendra Reddy
> 
> On 9 April 2013 16:23, Jaehoon Chung <jh80.chung at samsung.com> wrote:
> 
>> On 04/03/2013 11:08 PM, Amar wrote:
>>> This patch adds FDT support for DWMMC, by reading the DWMMC node data
>>> from the device tree and initialising DWMMC channels as per data
>>> obtained from the node.
>>>
>>> Signed-off-by: Vivek Gautam <gautam.vivek at samsung.com>
>>> Signed-off-by: Amar <amarendra.xt at samsung.com>
>>> Acked-by: Simon Glass <sjg at chromium.org>
>>> ---
>>> Changes since V1:
>>>       1)Updated code to have same signature for the function
>>>       exynos_dwmci_init() for both FDT and non-FDT versions.
>>>       2)Updated code to pass device_id parameter to the function
>>>       exynos5_mmc_set_clk_div() instead of index.
>>>       3)Updated code to decode the value of "samsung,width" from FDT.
>>>       4)Channel index is computed instead of getting from FDT.
>>>
>>> Changes since V2:
>>>       1)Updation of commit message and resubmition of proper patch set.
>>>
>>> Changes since V3:
>>>       1)Replaced the new function exynos5_mmc_set_clk_div() with the
>>>       existing function set_mmc_clk(). set_mmc_clk() will do the purpose.
>>>       2)Computation of FSYS block clock divisor (pre-ratio) is added.
>>>
>>> Changes since V4:
>>>       1)Replaced "unsigned int exynos_dwmmc_init(int index, int
>> bus_width)" with
>>>       int exynos_dwmci_add_port(int, u32, inth, u32)
>>>               i)exynos_dwmmc_add_port() will be used by non-FDT boards.
>>>               ii)In FDT case, exynos_dwmmc_init(const void *blob) will
>> use
>>>               exynos_dwmmc_add_port() for every channel enabled in
>> device node.
>>>       2)Changed the computation method of mmc clock divisor.
>>>       3)Updated exynos_dwmmc_init() to compute the 'clksel_val' within
>> the function.
>>>
>>> Changes since V5:
>>>       1)Updated in response to review comments and changed the mmc clock
>> value
>>>       from 50MHz to 52MHz.
>>>
>>> Changes since V6:
>>>       No change.
>>>
>>> Changes since V7:
>>>       No change.
>>>
>>>  arch/arm/include/asm/arch-exynos/dwmmc.h |  11 +--
>>>  drivers/mmc/exynos_dw_mmc.c              | 127
>> ++++++++++++++++++++++++++++---
>>>  include/dwmmc.h                          |   3 +
>>>  3 files changed, 124 insertions(+), 17 deletions(-)
>>>
>>> diff --git a/arch/arm/include/asm/arch-exynos/dwmmc.h
>> b/arch/arm/include/asm/arch-exynos/dwmmc.h
>>> index 8acdf9b..3b147b8 100644
>>> --- a/arch/arm/include/asm/arch-exynos/dwmmc.h
>>> +++ b/arch/arm/include/asm/arch-exynos/dwmmc.h
>>> @@ -27,10 +27,7 @@
>>>  #define DWMCI_SET_DRV_CLK(x) ((x) << 16)
>>>  #define DWMCI_SET_DIV_RATIO(x)       ((x) << 24)
>>>
>>> -int exynos_dwmci_init(u32 regbase, int bus_width, int index);
>>> -
>>> -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);
>>> -}
>>> +#ifdef CONFIG_OF_CONTROL
>>> +int exynos_dwmmc_init(const void *blob);
>>> +#endif
>>> +int exynos_dwmci_add_port(int index, u32 regbase, int bus_width, u32
>> clksel);
>>> diff --git a/drivers/mmc/exynos_dw_mmc.c b/drivers/mmc/exynos_dw_mmc.c
>>> index 72a31b7..4238dd9 100644
>>> --- a/drivers/mmc/exynos_dw_mmc.c
>>> +++ b/drivers/mmc/exynos_dw_mmc.c
>>> @@ -19,39 +19,146 @@
>>>   */
>>>
>>>  #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>
>>>
>>> -static char *EXYNOS_NAME = "EXYNOS DWMMC";
>>> +#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
>> I known that CLKSEL's value is SoC specific.
>> All exynos series are working fine? I didn't think so.
>>
>> Best Regards,
>> Jaehoon Chung
>>
> 
> The above values of CLKSEL work fine for Exynos5 (5250 & 5410) and is
> tested.
> 
> The above CLKSEL values donot hold good for Exynos4 series. Exynos4 has
> "Mobile Storage Host" with only one port.
> But this file 'drivers/mmc/exynos_dw_mmc.c' is specific to Exynos5 series
> and gets compiled only when CONFIG_EXYNOS_DWMMC is defined.
No, driver/mmc/exynos_dw_mmc.c isn't specific to Exynos5 series.
We can use this controller at the exynos4.
Then we need to consider how get the clksel value according to SoC.

Best Regards,
Jaehoon Chung
> 
>>
>>> +/*
>>> + * Function used as callback function to initialise the
>>> + * CLKSEL register for every mmc channel.
>>> + */
>>>  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);
>>>  }
>>>
>>> -int exynos_dwmci_init(u32 regbase, int bus_width, int index)
>>> +/*
>>> + * This function adds the mmc channel to be registered with mmc core.
>>> + * index -   mmc channel number.
>>> + * regbase - register base address of mmc channel specified in 'index'.
>>> + * bus_width -       operating bus width of mmc channel specified in
>> 'index'.
>>> + * clksel -  value to be written into CLKSEL register in case of FDT.
>>> + *           NULL in case od non-FDT.
>>> + */
>>> +int exynos_dwmci_add_port(int index, u32 regbase, int bus_width, u32
>> clksel)
>>>  {
>>>       struct dwmci_host *host = NULL;
>>> +     unsigned int div;
>>> +     unsigned long freq, sclk;
>>>       host = malloc(sizeof(struct dwmci_host));
>>>       if (!host) {
>>>               printf("dwmci_host malloc fail!\n");
>>>               return 1;
>>>       }
>>> +     /* request mmc clock vlaue of 52MHz.  */
>>> +     freq = 52000000;
>>> +     sclk = get_mmc_clk(index);
>>> +     div = DIV_ROUND_UP(sclk, freq);
>>> +     /* set the clock divisor for mmc */
>>> +     set_mmc_clk(index, div);
>>>
>>> -     host->name = EXYNOS_NAME;
>>> +     host->name = "EXYNOS DWMMC";
>>>       host->ioaddr = (void *)regbase;
>>>       host->buswidth = bus_width;
>>> +
>>> +     if (clksel) {
>>> +             host->clksel_val = clksel;
>>> +     } else {
>>> +             if (0 == index)
>>> +                     host->clksel_val = DWMMC_MMC0_CLKSEL_VAL;
>>> +             if (2 == index)
>>> +                     host->clksel_val = DWMMC_MMC2_CLKSEL_VAL;
>>> +     }
>>> +
>>>       host->clksel = exynos_dwmci_clksel;
>>>       host->dev_index = index;
>>> +     host->mmc_clk = exynos_dwmci_get_clk;
>>> +     /* Add the mmc channel to be registered with mmc core */
>>> +     if (add_dwmci(host, DWMMC_MAX_FREQ, DWMMC_MIN_FREQ)) {
>>> +             debug("dwmmc%d registration failed\n", index);
>>> +             return -1;
>>> +     }
>>> +     return 0;
>>> +}
>>> +
>>> +#ifdef CONFIG_OF_CONTROL
>>> +int exynos_dwmmc_init(const void *blob)
>>> +{
>>> +     int index, bus_width;
>>> +     int node_list[DWMMC_MAX_CH_NUM];
>>> +     int err = 0, dev_id, flag, count, i;
>>> +     u32 clksel_val, base, timing[3];
>>> +
>>> +     count = fdtdec_find_aliases_for_id(blob, "mmc",
>>> +                             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;
>>>
>>> -     add_dwmci(host, 52000000, 400000);
>>> +             /* Extract device id for each mmc channel */
>>> +             dev_id = pinmux_decode_periph_id(blob, node);
>>>
>>> +             /* Get the bus width from the device node */
>>> +             bus_width = fdtdec_get_int(blob, node,
>> "samsung,bus-width", 0);
>>> +             if (bus_width <= 0) {
>>> +                     debug("DWMMC: Can't get bus-width\n");
>>> +                     return -1;
>>> +             }
>>> +             if (8 == bus_width)
>>> +                     flag = PINMUX_FLAG_8BIT_MODE;
>>> +             else
>>> +                     flag = PINMUX_FLAG_NONE;
>>> +
>>> +             /* config pinmux for each mmc channel */
>>> +             err = exynos_pinmux_config(dev_id, flag);
>>> +             if (err) {
>>> +                     debug("DWMMC not configured\n");
>>> +                     return err;
>>> +             }
>>> +
>>> +             index = dev_id - PERIPH_ID_SDMMC0;
>>> +
>>> +             /* 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;
>>> +             }
>>> +             /* Extract the timing info from the node */
>>> +             err = fdtdec_get_int_array(blob, node, "samsung,timing",
>>> +                                     timing, 3);
>>> +             if (err) {
>>> +                     debug("Can't get sdr-timings for divider\n");
>>> +                     return -1;
>>> +             }
>>> +
>>> +             clksel_val = (DWMCI_SET_SAMPLE_CLK(timing[0]) |
>>> +                             DWMCI_SET_DRV_CLK(timing[1]) |
>>> +                             DWMCI_SET_DIV_RATIO(timing[2]));
>>> +             /* Initialise each mmc channel */
>>> +             err = exynos_dwmci_add_port(index, base, bus_width,
>> clksel_val);
>>> +             if (err)
>>> +                     debug("dwmmc Channel-%d init failed\n", index);
>>> +     }
>>>       return 0;
>>>  }
>>> -
>>> +#endif
>>> diff --git a/include/dwmmc.h b/include/dwmmc.h
>>> index c8b1d40..e142f3e 100644
>>> --- a/include/dwmmc.h
>>> +++ b/include/dwmmc.h
>>> @@ -123,6 +123,8 @@
>>>  #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)
>>>
>>>  #define DWMCI_IDMAC_OWN              (1 << 31)
>>>  #define DWMCI_IDMAC_CH               (1 << 4)
>>> @@ -144,6 +146,7 @@ struct dwmci_host {
>>>       unsigned int bus_hz;
>>>       int dev_index;
>>>       int buswidth;
>>> +     u32 clksel_val;
>>>       u32 fifoth_val;
>>>       struct mmc *mmc;
>>>
>>>
>>
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> 
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