From 65fc7f9957c52ad4fdf4ee5dfe3a75aa0a633d39 Mon Sep 17 00:00:00 2001 From: Gabor Juhos Date: Sat, 1 Sep 2012 18:46:00 +0200 Subject: MIPS: ath79: use correct fractional dividers for {CPU,DDR}_PLL on AR934x The current dividers in the code are wrong and this leads to broken CPU frequency calculation on boards where the fractional part is used. For example, if the SoC is running from a 40MHz reference clock, refdiv=1, nint=14, outdiv=0 and nfrac=31 the real frequency is 579.375MHz but the current code calculates 569.687MHz instead. Because the system time is indirectly related to the CPU frequency the broken computation causes drift in the system time. The correct divider is 2^6 for the CPU PLL and 2^10 for the DDR PLL. Use the correct values to fix the issue. Signed-off-by: Gabor Juhos Cc: stable@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/4305/ Signed-off-by: Ralf Baechle --- arch/mips/ath79/clock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/mips/ath79/clock.c') diff --git a/arch/mips/ath79/clock.c b/arch/mips/ath79/clock.c index b91ad3efe29e..d2728573e9fc 100644 --- a/arch/mips/ath79/clock.c +++ b/arch/mips/ath79/clock.c @@ -189,7 +189,7 @@ static void __init ar934x_clocks_init(void) AR934X_PLL_CPU_CONFIG_NFRAC_MASK; cpu_pll = nint * ath79_ref_clk.rate / ref_div; - cpu_pll += frac * ath79_ref_clk.rate / (ref_div * (2 << 6)); + cpu_pll += frac * ath79_ref_clk.rate / (ref_div * (1 << 6)); cpu_pll /= (1 << out_div); pll = ath79_pll_rr(AR934X_PLL_DDR_CONFIG_REG); @@ -203,7 +203,7 @@ static void __init ar934x_clocks_init(void) AR934X_PLL_DDR_CONFIG_NFRAC_MASK; ddr_pll = nint * ath79_ref_clk.rate / ref_div; - ddr_pll += frac * ath79_ref_clk.rate / (ref_div * (2 << 10)); + ddr_pll += frac * ath79_ref_clk.rate / (ref_div * (1 << 10)); ddr_pll /= (1 << out_div); clk_ctrl = ath79_pll_rr(AR934X_PLL_CPU_DDR_CLK_CTRL_REG); -- cgit v1.2.2 From 97541ccfb9db2bb9cd1dde6344d5834438d14bda Mon Sep 17 00:00:00 2001 From: Gabor Juhos Date: Sat, 8 Sep 2012 14:02:21 +0200 Subject: MIPS: ath79: Fix CPU/DDR frequency calculation for SRIF PLLs Besides the CPU and DDR PLLs, the CPU and DDR frequencies can be derived from other PLLs in the SRIF block on the AR934x SoCs. The current code does not checks if the SRIF PLLs are used and this can lead to incorrectly calculated CPU/DDR frequencies. Fix it by calculating the frequencies from SRIF PLLs if those are used on a given board. Signed-off-by: Gabor Juhos Cc: Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/4324/ Signed-off-by: Ralf Baechle --- arch/mips/ath79/clock.c | 109 +++++++++++++++++++++++++++++++++++------------- 1 file changed, 81 insertions(+), 28 deletions(-) (limited to 'arch/mips/ath79/clock.c') diff --git a/arch/mips/ath79/clock.c b/arch/mips/ath79/clock.c index d2728573e9fc..579f452c0b45 100644 --- a/arch/mips/ath79/clock.c +++ b/arch/mips/ath79/clock.c @@ -17,6 +17,8 @@ #include #include +#include + #include #include #include "common.h" @@ -166,11 +168,34 @@ static void __init ar933x_clocks_init(void) ath79_uart_clk.rate = ath79_ref_clk.rate; } +static u32 __init ar934x_get_pll_freq(u32 ref, u32 ref_div, u32 nint, u32 nfrac, + u32 frac, u32 out_div) +{ + u64 t; + u32 ret; + + t = ath79_ref_clk.rate; + t *= nint; + do_div(t, ref_div); + ret = t; + + t = ath79_ref_clk.rate; + t *= nfrac; + do_div(t, ref_div * frac); + ret += t; + + ret /= (1 << out_div); + return ret; +} + static void __init ar934x_clocks_init(void) { - u32 pll, out_div, ref_div, nint, frac, clk_ctrl, postdiv; + u32 pll, out_div, ref_div, nint, nfrac, frac, clk_ctrl, postdiv; u32 cpu_pll, ddr_pll; u32 bootstrap; + void __iomem *dpll_base; + + dpll_base = ioremap(AR934X_SRIF_BASE, AR934X_SRIF_SIZE); bootstrap = ath79_reset_rr(AR934X_RESET_REG_BOOTSTRAP); if (bootstrap & AR934X_BOOTSTRAP_REF_CLK_40) @@ -178,33 +203,59 @@ static void __init ar934x_clocks_init(void) else ath79_ref_clk.rate = 25 * 1000 * 1000; - pll = ath79_pll_rr(AR934X_PLL_CPU_CONFIG_REG); - out_div = (pll >> AR934X_PLL_CPU_CONFIG_OUTDIV_SHIFT) & - AR934X_PLL_CPU_CONFIG_OUTDIV_MASK; - ref_div = (pll >> AR934X_PLL_CPU_CONFIG_REFDIV_SHIFT) & - AR934X_PLL_CPU_CONFIG_REFDIV_MASK; - nint = (pll >> AR934X_PLL_CPU_CONFIG_NINT_SHIFT) & - AR934X_PLL_CPU_CONFIG_NINT_MASK; - frac = (pll >> AR934X_PLL_CPU_CONFIG_NFRAC_SHIFT) & - AR934X_PLL_CPU_CONFIG_NFRAC_MASK; - - cpu_pll = nint * ath79_ref_clk.rate / ref_div; - cpu_pll += frac * ath79_ref_clk.rate / (ref_div * (1 << 6)); - cpu_pll /= (1 << out_div); - - pll = ath79_pll_rr(AR934X_PLL_DDR_CONFIG_REG); - out_div = (pll >> AR934X_PLL_DDR_CONFIG_OUTDIV_SHIFT) & - AR934X_PLL_DDR_CONFIG_OUTDIV_MASK; - ref_div = (pll >> AR934X_PLL_DDR_CONFIG_REFDIV_SHIFT) & - AR934X_PLL_DDR_CONFIG_REFDIV_MASK; - nint = (pll >> AR934X_PLL_DDR_CONFIG_NINT_SHIFT) & - AR934X_PLL_DDR_CONFIG_NINT_MASK; - frac = (pll >> AR934X_PLL_DDR_CONFIG_NFRAC_SHIFT) & - AR934X_PLL_DDR_CONFIG_NFRAC_MASK; - - ddr_pll = nint * ath79_ref_clk.rate / ref_div; - ddr_pll += frac * ath79_ref_clk.rate / (ref_div * (1 << 10)); - ddr_pll /= (1 << out_div); + pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL2_REG); + if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) { + out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) & + AR934X_SRIF_DPLL2_OUTDIV_MASK; + pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL1_REG); + nint = (pll >> AR934X_SRIF_DPLL1_NINT_SHIFT) & + AR934X_SRIF_DPLL1_NINT_MASK; + nfrac = pll & AR934X_SRIF_DPLL1_NFRAC_MASK; + ref_div = (pll >> AR934X_SRIF_DPLL1_REFDIV_SHIFT) & + AR934X_SRIF_DPLL1_REFDIV_MASK; + frac = 1 << 18; + } else { + pll = ath79_pll_rr(AR934X_PLL_CPU_CONFIG_REG); + out_div = (pll >> AR934X_PLL_CPU_CONFIG_OUTDIV_SHIFT) & + AR934X_PLL_CPU_CONFIG_OUTDIV_MASK; + ref_div = (pll >> AR934X_PLL_CPU_CONFIG_REFDIV_SHIFT) & + AR934X_PLL_CPU_CONFIG_REFDIV_MASK; + nint = (pll >> AR934X_PLL_CPU_CONFIG_NINT_SHIFT) & + AR934X_PLL_CPU_CONFIG_NINT_MASK; + nfrac = (pll >> AR934X_PLL_CPU_CONFIG_NFRAC_SHIFT) & + AR934X_PLL_CPU_CONFIG_NFRAC_MASK; + frac = 1 << 6; + } + + cpu_pll = ar934x_get_pll_freq(ath79_ref_clk.rate, ref_div, nint, + nfrac, frac, out_div); + + pll = __raw_readl(dpll_base + AR934X_SRIF_DDR_DPLL2_REG); + if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) { + out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) & + AR934X_SRIF_DPLL2_OUTDIV_MASK; + pll = __raw_readl(dpll_base + AR934X_SRIF_DDR_DPLL1_REG); + nint = (pll >> AR934X_SRIF_DPLL1_NINT_SHIFT) & + AR934X_SRIF_DPLL1_NINT_MASK; + nfrac = pll & AR934X_SRIF_DPLL1_NFRAC_MASK; + ref_div = (pll >> AR934X_SRIF_DPLL1_REFDIV_SHIFT) & + AR934X_SRIF_DPLL1_REFDIV_MASK; + frac = 1 << 18; + } else { + pll = ath79_pll_rr(AR934X_PLL_DDR_CONFIG_REG); + out_div = (pll >> AR934X_PLL_DDR_CONFIG_OUTDIV_SHIFT) & + AR934X_PLL_DDR_CONFIG_OUTDIV_MASK; + ref_div = (pll >> AR934X_PLL_DDR_CONFIG_REFDIV_SHIFT) & + AR934X_PLL_DDR_CONFIG_REFDIV_MASK; + nint = (pll >> AR934X_PLL_DDR_CONFIG_NINT_SHIFT) & + AR934X_PLL_DDR_CONFIG_NINT_MASK; + nfrac = (pll >> AR934X_PLL_DDR_CONFIG_NFRAC_SHIFT) & + AR934X_PLL_DDR_CONFIG_NFRAC_MASK; + frac = 1 << 10; + } + + ddr_pll = ar934x_get_pll_freq(ath79_ref_clk.rate, ref_div, nint, + nfrac, frac, out_div); clk_ctrl = ath79_pll_rr(AR934X_PLL_CPU_DDR_CLK_CTRL_REG); @@ -240,6 +291,8 @@ static void __init ar934x_clocks_init(void) ath79_wdt_clk.rate = ath79_ref_clk.rate; ath79_uart_clk.rate = ath79_ref_clk.rate; + + iounmap(dpll_base); } void __init ath79_clocks_init(void) -- cgit v1.2.2