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authorSiarhei Siamashka <siarhei.siamashka@gmail.com>2015-11-20 07:07:48 +0200
committerHans de Goede <hdegoede@redhat.com>2015-11-22 11:31:00 +0100
commit52d093112a307b2dd1ae46f8bd6ba7904760ac57 (patch)
treea590cdeec5e083aa81f33686d30b10ac41a67afa /arch
parent0404d53f2f2024312b108a1b692bf668545b772b (diff)
sunxi: clock: Set AHB1 clock frequency to 200MHz on Allwinner H3
The 3.4 kernel from the Allwinner SDK is clocking AHB1 at 200MHz on Allwinner H3 and using PLL6 as the clock source (PLL6/3). This can be verified by reading the value of the AHB1_APB1_CFG_REG register via /dev/mem. It always reads as 0x3180 regardless of the current cpufreq operating point. So this configuration should be safe for use in U-Boot too. PLL6 also needs to be configured before it is used as the clock source, according to the "CCU / Programming Guidelines" section of the Allwinner manual. The current low AHB1 clock speed is limiting the USB transfer speed when booting via FEL. This patch can increase the FEL USB transfer speed from ~510 KB/s to ~950 KB/s. Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/cpu/armv7/sunxi/clock_sun6i.c6
-rw-r--r--arch/arm/include/asm/arch-sunxi/clock_sun6i.h7
2 files changed, 10 insertions, 3 deletions
diff --git a/arch/arm/cpu/armv7/sunxi/clock_sun6i.c b/arch/arm/cpu/armv7/sunxi/clock_sun6i.c
index 3ab3b31867..916ee48e4b 100644
--- a/arch/arm/cpu/armv7/sunxi/clock_sun6i.c
+++ b/arch/arm/cpu/armv7/sunxi/clock_sun6i.c
@@ -34,9 +34,11 @@ void clock_init_safe(void)
clock_set_pll1(408000000);
- writel(AHB1_ABP1_DIV_DEFAULT, &ccm->ahb1_apb1_div);
-
writel(PLL6_CFG_DEFAULT, &ccm->pll6_cfg);
+ while (!(readl(&ccm->pll6_cfg) & CCM_PLL6_CTRL_LOCK))
+ ;
+
+ writel(AHB1_ABP1_DIV_DEFAULT, &ccm->ahb1_apb1_div);
writel(MBUS_CLK_DEFAULT, &ccm->mbus0_clk_cfg);
writel(MBUS_CLK_DEFAULT, &ccm->mbus1_clk_cfg);
diff --git a/arch/arm/include/asm/arch-sunxi/clock_sun6i.h b/arch/arm/include/asm/arch-sunxi/clock_sun6i.h
index 584d351cb4..09337a1dea 100644
--- a/arch/arm/include/asm/arch-sunxi/clock_sun6i.h
+++ b/arch/arm/include/asm/arch-sunxi/clock_sun6i.h
@@ -201,6 +201,7 @@ struct sunxi_ccm_reg {
#define CCM_PLL6_CTRL_N_MASK (0x1f << CCM_PLL6_CTRL_N_SHIFT)
#define CCM_PLL6_CTRL_K_SHIFT 4
#define CCM_PLL6_CTRL_K_MASK (0x3 << CCM_PLL6_CTRL_K_SHIFT)
+#define CCM_PLL6_CTRL_LOCK (1 << 28)
#define CCM_MIPI_PLL_CTRL_M_SHIFT 0
#define CCM_MIPI_PLL_CTRL_M_MASK (0xf << CCM_MIPI_PLL_CTRL_M_SHIFT)
@@ -219,7 +220,11 @@ struct sunxi_ccm_reg {
#define CCM_PLL11_CTRL_UPD (0x1 << 30)
#define CCM_PLL11_CTRL_EN (0x1 << 31)
-#define AHB1_ABP1_DIV_DEFAULT 0x00002020
+#if defined CONFIG_MACH_SUN8I_H3
+#define AHB1_ABP1_DIV_DEFAULT 0x00003180 /* AHB1=PLL6/3,APB1=AHB1/2 */
+#else
+#define AHB1_ABP1_DIV_DEFAULT 0x00002020 /* AHB1=AXI/4, APB1=AHB1/2 */
+#endif
#define AXI_GATE_OFFSET_DRAM 0