Re: [PATCH v3 06/23] mips: mtmips: add support to initialize SDRAM

[Stefan Roese]

On 09.11.20 09:24, Weijie Gao wrote:

This patch adds support for mtmips SoCs to initialize the SDRAM.

Signed-off-by: Weijie Gao <weijie....@mediatek.com>

Reviewed-by: Stefan Roese <s...@denx.de>

Thanks,
Stefan

---
v3 changes: none
v2 changes: none
---
  arch/mips/mach-mtmips/ddr_init.c         | 59 ++++++++++++++++++++++++
  arch/mips/mach-mtmips/include/mach/ddr.h |  4 ++
  2 files changed, 63 insertions(+)

diff --git a/arch/mips/mach-mtmips/ddr_init.c b/arch/mips/mach-mtmips/ddr_init.c
index 6c6d0933f2..9c986daea6 100644
--- a/arch/mips/mach-mtmips/ddr_init.c
+++ b/arch/mips/mach-mtmips/ddr_init.c
@@ -15,6 +15,13 @@

#define DDR_BW_TEST_PAT 0xaa5555aa +static const u32 sdr_size_cfg1[] = {

+       [DRAM_8MB] = (1 << NUMROWS_S),
+       [DRAM_16MB] = (1 << NUMROWS_S) | (1 << NUMCOLS_S),
+       [DRAM_32MB] = (2 << NUMROWS_S) | (1 << NUMCOLS_S),
+       [DRAM_64MB] = (2 << NUMROWS_S) | (2 << NUMCOLS_S),
+};
+
  static const u32 dram_size[] = {
        [DRAM_8MB] = SZ_8M,
        [DRAM_16MB] = SZ_16M,
@@ -193,3 +200,55 @@ void ddr2_init(struct mc_ddr_init_param *param)
        param->memsize = dram_size[sz];
        param->bus_width = bw;
  }
+
+static void mc_sdr_init(void __iomem *memc, mc_reset_t mc_reset, u32 cfg0,
+                       u32 cfg1)
+{
+       mc_reset(1);
+       __udelay(200);
+       mc_reset(0);
+
+       writel(cfg0, memc + MEMCTL_SDRAM_CFG0_REG);
+       writel(cfg1, memc + MEMCTL_SDRAM_CFG1_REG);
+
+       while (!(readl(memc + MEMCTL_SDRAM_CFG1_REG) & SDRAM_INIT_DONE))
+               ;
+
+       clrsetbits_32(memc + MEMCTL_PWR_SAVE_CNT_REG, SR_TAR_CNT_M,
+                     1 << SR_TAR_CNT_S);
+
+       setbits_32(memc + MEMCTL_DDR_SELF_REFRESH_REG, SR_AUTO_EN);
+}
+
+void sdr_init(struct mc_ddr_init_param *param)
+{
+       enum mc_dram_size sz;
+       u32 cfg1;
+
+       cfg1 = param->sdr_cfg1 | SDRAM_INIT_START;
+       cfg1 &= ~(NUMCOLS_M | NUMROWS_M);
+
+       /* First initialization, determine SDR capacity */
+       mc_sdr_init(param->memc, param->mc_reset, param->sdr_cfg0,
+                   cfg1 | sdr_size_cfg1[DRAM_64MB]);
+
+       if (dram_addr_test_bit(9)) {
+               sz = DRAM_8MB;
+       } else {
+               if (dram_addr_test_bit(10)) {
+                       if (dram_addr_test_bit(23))
+                               sz = DRAM_16MB;
+                       else
+                               sz = DRAM_32MB;
+               } else {
+                       sz = DRAM_64MB;
+               }
+       }
+
+       /* Final initialization */
+       mc_sdr_init(param->memc, param->mc_reset, param->sdr_cfg0,
+                   cfg1 | sdr_size_cfg1[sz]);
+
+       /* Return actual DDR configuration */
+       param->memsize = dram_size[sz];
+}
diff --git a/arch/mips/mach-mtmips/include/mach/ddr.h 
b/arch/mips/mach-mtmips/include/mach/ddr.h
index f92198137b..15ff66ace6 100644
--- a/arch/mips/mach-mtmips/include/mach/ddr.h
+++ b/arch/mips/mach-mtmips/include/mach/ddr.h
@@ -35,6 +35,9 @@ typedef void (*mc_reset_t)(int assert);
  struct mc_ddr_init_param {
        void __iomem *memc;

+ u32 sdr_cfg0;

+       u32 sdr_cfg1;
+
        u32 dq_dly;
        u32 dqs_dly;

@@ -45,6 +48,7 @@ struct mc_ddr_init_param {

        u32 bus_width;
  };

+void sdr_init(struct mc_ddr_init_param *param);

  void ddr1_init(struct mc_ddr_init_param *param);
  void ddr2_init(struct mc_ddr_init_param *param);
  void ddr_calibrate(void __iomem *memc, u32 memsize, u32 bw);

Viele Grüße,
Stefan

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