drivers/mmc/exynos_dw_mmc.c

   1 /*
   2  * (C) Copyright 2012 SAMSUNG Electronics
   3  * Jaehoon Chung <jh80.chung@samsung.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <dwmmc.h>
  10 #include <fdtdec.h>
  11 #include <libfdt.h>
  12 #include <malloc.h>
  13 #include <asm/arch/dwmmc.h>
  14 #include <asm/arch/clk.h>
  15 #include <asm/arch/pinmux.h>
  16
  17 #define DWMMC_MAX_CH_NUM                4
  18 #define DWMMC_MAX_FREQ                  52000000
  19 #define DWMMC_MIN_FREQ                  400000
  20 #define DWMMC_MMC0_CLKSEL_VAL           0x03030001
  21 #define DWMMC_MMC2_CLKSEL_VAL           0x03020001
  22
  23 /*
  24  * Function used as callback function to initialise the
  25  * CLKSEL register for every mmc channel.
  26  */
  27 static void exynos_dwmci_clksel(struct dwmci_host *host)
  28 {
  29         dwmci_writel(host, DWMCI_CLKSEL, host->clksel_val);
  30 }
  31
  32 unsigned int exynos_dwmci_get_clk(int dev_index)
  33 {
  34         return get_mmc_clk(dev_index);
  35 }
  36
  37 /*
  38  * This function adds the mmc channel to be registered with mmc core.
  39  * index -      mmc channel number.
  40  * regbase -    register base address of mmc channel specified in 'index'.
  41  * bus_width -  operating bus width of mmc channel specified in 'index'.
  42  * clksel -     value to be written into CLKSEL register in case of FDT.
  43  *              NULL in case od non-FDT.
  44  */
  45 int exynos_dwmci_add_port(int index, u32 regbase, int bus_width, u32 clksel)
  46 {
  47         struct dwmci_host *host = NULL;
  48         unsigned int div;
  49         unsigned long freq, sclk;
  50         host = malloc(sizeof(struct dwmci_host));
  51         if (!host) {
  52                 printf("dwmci_host malloc fail!\n");
  53                 return 1;
  54         }
  55         /* request mmc clock vlaue of 52MHz.  */
  56         freq = 52000000;
  57         sclk = get_mmc_clk(index);
  58         div = DIV_ROUND_UP(sclk, freq);
  59         /* set the clock divisor for mmc */
  60         set_mmc_clk(index, div);
  61
  62         host->name = "EXYNOS DWMMC";
  63         host->ioaddr = (void *)regbase;
  64         host->buswidth = bus_width;
  65
  66         if (clksel) {
  67                 host->clksel_val = clksel;
  68         } else {
  69                 if (0 == index)
  70                         host->clksel_val = DWMMC_MMC0_CLKSEL_VAL;
  71                 if (2 == index)
  72                         host->clksel_val = DWMMC_MMC2_CLKSEL_VAL;
  73         }
  74
  75         host->clksel = exynos_dwmci_clksel;
  76         host->dev_index = index;
  77         host->mmc_clk = exynos_dwmci_get_clk;
  78         /* Add the mmc channel to be registered with mmc core */
  79         if (add_dwmci(host, DWMMC_MAX_FREQ, DWMMC_MIN_FREQ)) {
  80                 debug("dwmmc%d registration failed\n", index);
  81                 return -1;
  82         }
  83         return 0;
  84 }
  85
  86 #ifdef CONFIG_OF_CONTROL
  87 int exynos_dwmmc_init(const void *blob)
  88 {
  89         int index, bus_width;
  90         int node_list[DWMMC_MAX_CH_NUM];
  91         int err = 0, dev_id, flag, count, i;
  92         u32 clksel_val, base, timing[3];
  93
  94         count = fdtdec_find_aliases_for_id(blob, "mmc",
  95                                 COMPAT_SAMSUNG_EXYNOS5_DWMMC, node_list,
  96                                 DWMMC_MAX_CH_NUM);
  97
  98         for (i = 0; i < count; i++) {
  99                 int node = node_list[i];
 100
 101                 if (node <= 0)
 102                         continue;
 103
 104                 /* Extract device id for each mmc channel */
 105                 dev_id = pinmux_decode_periph_id(blob, node);
 106
 107                 /* Get the bus width from the device node */
 108                 bus_width = fdtdec_get_int(blob, node, "samsung,bus-width", 0);
 109                 if (bus_width <= 0) {
 110                         debug("DWMMC: Can't get bus-width\n");
 111                         return -1;
 112                 }
 113                 if (8 == bus_width)
 114                         flag = PINMUX_FLAG_8BIT_MODE;
 115                 else
 116                         flag = PINMUX_FLAG_NONE;
 117
 118                 /* config pinmux for each mmc channel */
 119                 err = exynos_pinmux_config(dev_id, flag);
 120                 if (err) {
 121                         debug("DWMMC not configured\n");
 122                         return err;
 123                 }
 124
 125                 index = dev_id - PERIPH_ID_SDMMC0;
 126
 127                 /* Get the base address from the device node */
 128                 base = fdtdec_get_addr(blob, node, "reg");
 129                 if (!base) {
 130                         debug("DWMMC: Can't get base address\n");
 131                         return -1;
 132                 }
 133                 /* Extract the timing info from the node */
 134                 err = fdtdec_get_int_array(blob, node, "samsung,timing",
 135                                         timing, 3);
 136                 if (err) {
 137                         debug("Can't get sdr-timings for divider\n");
 138                         return -1;
 139                 }
 140
 141                 clksel_val = (DWMCI_SET_SAMPLE_CLK(timing[0]) |
 142                                 DWMCI_SET_DRV_CLK(timing[1]) |
 143                                 DWMCI_SET_DIV_RATIO(timing[2]));
 144                 /* Initialise each mmc channel */
 145                 err = exynos_dwmci_add_port(index, base, bus_width, clksel_val);
 146                 if (err)
 147                         debug("dwmmc Channel-%d init failed\n", index);
 148         }
 149         return 0;
 150 }
 151 #endif