Release ddr clock reset once clock is initialized
Signed-off-by: Pragnesh Patel pragnesh.patel@sifive.com Reviewed-by: Bin Meng bmeng.cn@gmail.com Tested-by: Bin Meng bmeng.cn@gmail.com Reviewed-by: Jagan Teki jagan@amarulasolutions.com Tested-by: Jagan Teki jagan@amarulasolutions.com --- drivers/clk/sifive/fu540-prci.c | 51 +++++++++++++++++++++++++++++---- 1 file changed, 45 insertions(+), 6 deletions(-)
diff --git a/drivers/clk/sifive/fu540-prci.c b/drivers/clk/sifive/fu540-prci.c index 7052db4b8a..3728aa533c 100644 --- a/drivers/clk/sifive/fu540-prci.c +++ b/drivers/clk/sifive/fu540-prci.c @@ -153,6 +153,12 @@ #define PRCI_CLKMUXSTATUSREG_TLCLKSEL_STATUS_MASK \ (0x1 << PRCI_CLKMUXSTATUSREG_TLCLKSEL_STATUS_SHIFT)
+/* PROCMONCFG */ +#define PRCI_PROCMONCFG_OFFSET 0xF0 +#define PRCI_PROCMONCFG_CORE_CLOCK_SHIFT 24 +#define PRCI_PROCMONCFG_CORE_CLOCK_MASK \ + (0x1 << PRCI_PROCMONCFG_CORE_CLOCK_SHIFT) + /* * Private structures */ @@ -177,6 +183,7 @@ struct __prci_data { * @disable_bypass: fn ptr to code to not bypass the WRPLL (or NULL) * @cfg0_offs: WRPLL CFG0 register offset (in bytes) from the PRCI base address * @cfg1_offs: WRPLL CFG1 register offset (in bytes) from the PRCI base address + * @release_reset: fn ptr to code to release clock reset * * @enable_bypass and @disable_bypass are used for WRPLL instances * that contain a separate external glitchless clock mux downstream @@ -188,6 +195,7 @@ struct __prci_wrpll_data { void (*disable_bypass)(struct __prci_data *pd); u8 cfg0_offs; u8 cfg1_offs; + void (*release_reset)(struct __prci_data *pd); };
struct __prci_clock; @@ -477,6 +485,9 @@ static int sifive_fu540_prci_clock_enable(struct __prci_clock *pc, bool enable)
if (enable) { __prci_wrpll_write_cfg1(pd, pwd, PRCI_COREPLLCFG1_CKE_MASK); + + if (pwd->release_reset) + pwd->release_reset(pd); } else { u32 r;
@@ -496,11 +507,6 @@ static const struct __prci_clock_ops sifive_fu540_prci_wrpll_clk_ops = { .enable_clk = sifive_fu540_prci_clock_enable, };
-static const struct __prci_clock_ops sifive_fu540_prci_wrpll_ro_clk_ops = { - .recalc_rate = sifive_fu540_prci_wrpll_recalc_rate, - .enable_clk = sifive_fu540_prci_clock_enable, -}; - /* TLCLKSEL clock integration */
static unsigned long sifive_fu540_prci_tlclksel_recalc_rate( @@ -522,6 +528,38 @@ static const struct __prci_clock_ops sifive_fu540_prci_tlclksel_clk_ops = { .recalc_rate = sifive_fu540_prci_tlclksel_recalc_rate, };
+/** + * __prci_ddr_release_reset() - Release DDR reset + * @pd: struct __prci_data * for the PRCI containing the DDRCLK mux reg + * + */ +static void __prci_ddr_release_reset(struct __prci_data *pd) +{ + u32 v; + + v = __prci_readl(pd, PRCI_DEVICESRESETREG_OFFSET); + v |= PRCI_DEVICESRESETREG_DDR_CTRL_RST_N_MASK; + __prci_writel(v, PRCI_DEVICESRESETREG_OFFSET, pd); + + /* HACK to get the '1 full controller clock cycle'. */ + asm volatile ("fence"); + v = __prci_readl(pd, PRCI_DEVICESRESETREG_OFFSET); + v |= (PRCI_DEVICESRESETREG_DDR_AXI_RST_N_MASK | + PRCI_DEVICESRESETREG_DDR_AHB_RST_N_MASK | + PRCI_DEVICESRESETREG_DDR_PHY_RST_N_MASK); + __prci_writel(v, PRCI_DEVICESRESETREG_OFFSET, pd); + + /* HACK to get the '1 full controller clock cycle'. */ + asm volatile ("fence"); + + /* + * These take like 16 cycles to actually propagate. We can't go sending + * stuff before they come out of reset. So wait. + */ + for (int i = 0; i < 256; i++) + asm volatile ("nop"); +} + /* * PRCI integration data for each WRPLL instance */ @@ -536,6 +574,7 @@ static struct __prci_wrpll_data __prci_corepll_data = { static struct __prci_wrpll_data __prci_ddrpll_data = { .cfg0_offs = PRCI_DDRPLLCFG0_OFFSET, .cfg1_offs = PRCI_DDRPLLCFG1_OFFSET, + .release_reset = __prci_ddr_release_reset, };
static struct __prci_wrpll_data __prci_gemgxlpll_data = { @@ -557,7 +596,7 @@ static struct __prci_clock __prci_init_clocks[] = { [PRCI_CLK_DDRPLL] = { .name = "ddrpll", .parent_name = "hfclk", - .ops = &sifive_fu540_prci_wrpll_ro_clk_ops, + .ops = &sifive_fu540_prci_wrpll_clk_ops, .pwd = &__prci_ddrpll_data, }, [PRCI_CLK_GEMGXLPLL] = {