drivers/ram/stm32_sdram.c

   1 /*
   2  * (C) Copyright 2017
   3  * Vikas Manocha, <vikas.manocha@st.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <clk.h>
  10 #include <dm.h>
  11 #include <ram.h>
  12 #include <asm/io.h>
  13 #include <asm/arch/stm32.h>
  14
  15 DECLARE_GLOBAL_DATA_PTR;
  16
  17 struct stm32_fmc_regs {
  18         u32 sdcr1;      /* Control register 1 */
  19         u32 sdcr2;      /* Control register 2 */
  20         u32 sdtr1;      /* Timing register 1 */
  21         u32 sdtr2;      /* Timing register 2 */
  22         u32 sdcmr;      /* Mode register */
  23         u32 sdrtr;      /* Refresh timing register */
  24         u32 sdsr;       /* Status register */
  25 };
  26
  27 /*
  28  * FMC registers base
  29  */
  30 #define STM32_SDRAM_FMC         ((struct stm32_fmc_regs *)SDRAM_FMC_BASE)
  31
  32 /* Control register SDCR */
  33 #define FMC_SDCR_RPIPE_SHIFT    13      /* RPIPE bit shift */
  34 #define FMC_SDCR_RBURST_SHIFT   12      /* RBURST bit shift */
  35 #define FMC_SDCR_SDCLK_SHIFT    10      /* SDRAM clock divisor shift */
  36 #define FMC_SDCR_WP_SHIFT       9       /* Write protection shift */
  37 #define FMC_SDCR_CAS_SHIFT      7       /* CAS latency shift */
  38 #define FMC_SDCR_NB_SHIFT       6       /* Number of banks shift */
  39 #define FMC_SDCR_MWID_SHIFT     4       /* Memory width shift */
  40 #define FMC_SDCR_NR_SHIFT       2       /* Number of row address bits shift */
  41 #define FMC_SDCR_NC_SHIFT       0       /* Number of col address bits shift */
  42
  43 /* Timings register SDTR */
  44 #define FMC_SDTR_TMRD_SHIFT     0       /* Load mode register to active */
  45 #define FMC_SDTR_TXSR_SHIFT     4       /* Exit self-refresh time */
  46 #define FMC_SDTR_TRAS_SHIFT     8       /* Self-refresh time */
  47 #define FMC_SDTR_TRC_SHIFT      12      /* Row cycle delay */
  48 #define FMC_SDTR_TWR_SHIFT      16      /* Recovery delay */
  49 #define FMC_SDTR_TRP_SHIFT      20      /* Row precharge delay */
  50 #define FMC_SDTR_TRCD_SHIFT     24      /* Row-to-column delay */
  51
  52 #define FMC_SDCMR_NRFS_SHIFT    5
  53
  54 #define FMC_SDCMR_MODE_NORMAL           0
  55 #define FMC_SDCMR_MODE_START_CLOCK      1
  56 #define FMC_SDCMR_MODE_PRECHARGE        2
  57 #define FMC_SDCMR_MODE_AUTOREFRESH      3
  58 #define FMC_SDCMR_MODE_WRITE_MODE       4
  59 #define FMC_SDCMR_MODE_SELFREFRESH      5
  60 #define FMC_SDCMR_MODE_POWERDOWN        6
  61
  62 #define FMC_SDCMR_BANK_1                BIT(4)
  63 #define FMC_SDCMR_BANK_2                BIT(3)
  64
  65 #define FMC_SDCMR_MODE_REGISTER_SHIFT   9
  66
  67 #define FMC_SDSR_BUSY                   BIT(5)
  68
  69 #define FMC_BUSY_WAIT()         do { \
  70                 __asm__ __volatile__ ("dsb" : : : "memory"); \
  71                 while (STM32_SDRAM_FMC->sdsr & FMC_SDSR_BUSY) \
  72                         ; \
  73         } while (0)
  74
  75 struct stm32_sdram_control {
  76         u8 no_columns;
  77         u8 no_rows;
  78         u8 memory_width;
  79         u8 no_banks;
  80         u8 cas_latency;
  81         u8 sdclk;
  82         u8 rd_burst;
  83         u8 rd_pipe_delay;
  84 };
  85
  86 struct stm32_sdram_timing {
  87         u8 tmrd;
  88         u8 txsr;
  89         u8 tras;
  90         u8 trc;
  91         u8 trp;
  92         u8 twr;
  93         u8 trcd;
  94 };
  95 struct stm32_sdram_params {
  96         u8 no_sdram_banks;
  97         struct stm32_sdram_control sdram_control;
  98         struct stm32_sdram_timing sdram_timing;
  99         u32 sdram_ref_count;
 100 };
 101
 102 #define SDRAM_MODE_BL_SHIFT     0
 103 #define SDRAM_MODE_CAS_SHIFT    4
 104 #define SDRAM_MODE_BL           0
 105
 106 int stm32_sdram_init(struct udevice *dev)
 107 {
 108         struct stm32_sdram_params *params = dev_get_platdata(dev);
 109
 110         writel(params->sdram_control.sdclk << FMC_SDCR_SDCLK_SHIFT
 111                 | params->sdram_control.cas_latency << FMC_SDCR_CAS_SHIFT
 112                 | params->sdram_control.no_banks << FMC_SDCR_NB_SHIFT
 113                 | params->sdram_control.memory_width << FMC_SDCR_MWID_SHIFT
 114                 | params->sdram_control.no_rows << FMC_SDCR_NR_SHIFT
 115                 | params->sdram_control.no_columns << FMC_SDCR_NC_SHIFT
 116                 | params->sdram_control.rd_pipe_delay << FMC_SDCR_RPIPE_SHIFT
 117                 | params->sdram_control.rd_burst << FMC_SDCR_RBURST_SHIFT,
 118                 &STM32_SDRAM_FMC->sdcr1);
 119
 120         writel(params->sdram_timing.trcd << FMC_SDTR_TRCD_SHIFT
 121                 | params->sdram_timing.trp << FMC_SDTR_TRP_SHIFT
 122                 | params->sdram_timing.twr << FMC_SDTR_TWR_SHIFT
 123                 | params->sdram_timing.trc << FMC_SDTR_TRC_SHIFT
 124                 | params->sdram_timing.tras << FMC_SDTR_TRAS_SHIFT
 125                 | params->sdram_timing.txsr << FMC_SDTR_TXSR_SHIFT
 126                 | params->sdram_timing.tmrd << FMC_SDTR_TMRD_SHIFT,
 127                 &STM32_SDRAM_FMC->sdtr1);
 128
 129         writel(FMC_SDCMR_BANK_1 | FMC_SDCMR_MODE_START_CLOCK,
 130                &STM32_SDRAM_FMC->sdcmr);
 131         udelay(200);    /* 200 us delay, page 10, "Power-Up" */
 132         FMC_BUSY_WAIT();
 133
 134         writel(FMC_SDCMR_BANK_1 | FMC_SDCMR_MODE_PRECHARGE,
 135                &STM32_SDRAM_FMC->sdcmr);
 136         udelay(100);
 137         FMC_BUSY_WAIT();
 138
 139         writel((FMC_SDCMR_BANK_1 | FMC_SDCMR_MODE_AUTOREFRESH
 140                 | 7 << FMC_SDCMR_NRFS_SHIFT), &STM32_SDRAM_FMC->sdcmr);
 141         udelay(100);
 142         FMC_BUSY_WAIT();
 143
 144         writel(FMC_SDCMR_BANK_1 | (SDRAM_MODE_BL << SDRAM_MODE_BL_SHIFT
 145                | params->sdram_control.cas_latency << SDRAM_MODE_CAS_SHIFT)
 146                << FMC_SDCMR_MODE_REGISTER_SHIFT | FMC_SDCMR_MODE_WRITE_MODE,
 147                &STM32_SDRAM_FMC->sdcmr);
 148         udelay(100);
 149         FMC_BUSY_WAIT();
 150
 151         writel(FMC_SDCMR_BANK_1 | FMC_SDCMR_MODE_NORMAL,
 152                &STM32_SDRAM_FMC->sdcmr);
 153         FMC_BUSY_WAIT();
 154
 155         /* Refresh timer */
 156         writel((params->sdram_ref_count) << 1, &STM32_SDRAM_FMC->sdrtr);
 157
 158         return 0;
 159 }
 160
 161 static int stm32_fmc_ofdata_to_platdata(struct udevice *dev)
 162 {
 163         int ret;
 164         int node = dev_of_offset(dev);
 165         const void *blob = gd->fdt_blob;
 166         struct stm32_sdram_params *params = dev_get_platdata(dev);
 167
 168         params->no_sdram_banks = fdtdec_get_uint(blob, node, "mr-nbanks", 1);
 169         debug("%s, no of banks = %d\n", __func__, params->no_sdram_banks);
 170
 171         fdt_for_each_subnode(node, blob, node) {
 172                 ret = fdtdec_get_byte_array(blob, node, "st,sdram-control",
 173                                             (u8 *)&params->sdram_control,
 174                                             sizeof(params->sdram_control));
 175                 if (ret)
 176                         return ret;
 177                 ret = fdtdec_get_byte_array(blob, node, "st,sdram-timing",
 178                                             (u8 *)&params->sdram_timing,
 179                                             sizeof(params->sdram_timing));
 180                 if (ret)
 181                         return ret;
 182
 183                 params->sdram_ref_count = fdtdec_get_int(blob, node,
 184                                                 "st,sdram-refcount", 8196);
 185         }
 186
 187         return 0;
 188 }
 189
 190 static int stm32_fmc_probe(struct udevice *dev)
 191 {
 192         int ret;
 193 #ifdef CONFIG_CLK
 194         struct clk clk;
 195
 196         ret = clk_get_by_index(dev, 0, &clk);
 197         if (ret < 0)
 198                 return ret;
 199
 200         ret = clk_enable(&clk);
 201
 202         if (ret) {
 203                 dev_err(dev, "failed to enable clock\n");
 204                 return ret;
 205         }
 206 #endif
 207         ret = stm32_sdram_init(dev);
 208         if (ret)
 209                 return ret;
 210
 211         return 0;
 212 }
 213
 214 static int stm32_fmc_get_info(struct udevice *dev, struct ram_info *info)
 215 {
 216         return 0;
 217 }
 218
 219 static struct ram_ops stm32_fmc_ops = {
 220         .get_info = stm32_fmc_get_info,
 221 };
 222
 223 static const struct udevice_id stm32_fmc_ids[] = {
 224         { .compatible = "st,stm32-fmc" },
 225         { }
 226 };
 227
 228 U_BOOT_DRIVER(stm32_fmc) = {
 229         .name = "stm32_fmc",
 230         .id = UCLASS_RAM,
 231         .of_match = stm32_fmc_ids,
 232         .ops = &stm32_fmc_ops,
 233         .ofdata_to_platdata = stm32_fmc_ofdata_to_platdata,
 234         .probe = stm32_fmc_probe,
 235         .platdata_auto_alloc_size = sizeof(struct stm32_sdram_params),
 236 };