On Thu, Mar 21 2019, Chuanhong Guo wrote: > For a long time the mt7621 uses a fixed cpu clock which causes a problem > if the cpu frequency is not 880MHz. > > This patch fixes the cpu clock calculation and adds the cpu/bus clkdev > which will be used in dts. > > Signed-off-by: Weijie Gao > > Ported from OpenWrt: > c7ca224299 ramips: fix cpu clock of mt7621 and add dt clk devices > > Signed-off-by: Chuanhong Guo Thanks for posting this. I've been using this patch on my mt7621 board (gnubee NAS) for a while and it is much better than having to specify the clock speed in the DTS file. Tested-by: NeilBrown Thanks, NeilBrown > --- > > Change since v1: > Correctly fix the following checkpatch.pl warning: > WARNING: Missing a blank line after declarations > #137: FILE: arch/mips/ralink/mt7621.c:146: > + u32 xtal_clk, cpu_clk, bus_clk; > + const static u32 prediv_tbl[] = {0, 1, 2, 2}; > > arch/mips/include/asm/mach-ralink/mt7621.h | 20 ++++ > arch/mips/ralink/mt7621.c | 102 ++++++++++++++------- > arch/mips/ralink/timer-gic.c | 4 +- > 3 files changed, 93 insertions(+), 33 deletions(-) > > diff --git a/arch/mips/include/asm/mach-ralink/mt7621.h b/arch/mips/include/asm/mach-ralink/mt7621.h > index a672e06fa5fd..b8a8834164c8 100644 > --- a/arch/mips/include/asm/mach-ralink/mt7621.h > +++ b/arch/mips/include/asm/mach-ralink/mt7621.h > @@ -19,6 +19,10 @@ > #define SYSC_REG_CHIP_REV 0x0c > #define SYSC_REG_SYSTEM_CONFIG0 0x10 > #define SYSC_REG_SYSTEM_CONFIG1 0x14 > +#define SYSC_REG_CLKCFG0 0x2c > +#define SYSC_REG_CUR_CLK_STS 0x44 > + > +#define MEMC_REG_CPU_PLL 0x648 > > #define CHIP_REV_PKG_MASK 0x1 > #define CHIP_REV_PKG_SHIFT 16 > @@ -26,6 +30,22 @@ > #define CHIP_REV_VER_SHIFT 8 > #define CHIP_REV_ECO_MASK 0xf > > +#define XTAL_MODE_SEL_MASK 0x7 > +#define XTAL_MODE_SEL_SHIFT 6 > + > +#define CPU_CLK_SEL_MASK 0x3 > +#define CPU_CLK_SEL_SHIFT 30 > + > +#define CUR_CPU_FDIV_MASK 0x1f > +#define CUR_CPU_FDIV_SHIFT 8 > +#define CUR_CPU_FFRAC_MASK 0x1f > +#define CUR_CPU_FFRAC_SHIFT 0 > + > +#define CPU_PLL_PREDIV_MASK 0x3 > +#define CPU_PLL_PREDIV_SHIFT 12 > +#define CPU_PLL_FBDIV_MASK 0x7f > +#define CPU_PLL_FBDIV_SHIFT 4 > + > #define MT7621_DRAM_BASE 0x0 > #define MT7621_DDR2_SIZE_MIN 32 > #define MT7621_DDR2_SIZE_MAX 256 > diff --git a/arch/mips/ralink/mt7621.c b/arch/mips/ralink/mt7621.c > index d2718de60b9b..6828eefb0a85 100644 > --- a/arch/mips/ralink/mt7621.c > +++ b/arch/mips/ralink/mt7621.c > @@ -9,22 +9,22 @@ > > #include > #include > +#include > +#include > +#include > +#include > > #include > #include > #include > #include > #include > +#include > > #include > > #include "common.h" > > -#define SYSC_REG_SYSCFG 0x10 > -#define SYSC_REG_CPLL_CLKCFG0 0x2c > -#define SYSC_REG_CUR_CLK_STS 0x44 > -#define CPU_CLK_SEL (BIT(30) | BIT(31)) > - > #define MT7621_GPIO_MODE_UART1 1 > #define MT7621_GPIO_MODE_I2C 2 > #define MT7621_GPIO_MODE_UART3_MASK 0x3 > @@ -110,49 +110,89 @@ static struct rt2880_pmx_group mt7621_pinmux_data[] = { > { 0 } > }; > > +static struct clk *clks[MT7621_CLK_MAX]; > +static struct clk_onecell_data clk_data = { > + .clks = clks, > + .clk_num = ARRAY_SIZE(clks), > +}; > + > phys_addr_t mips_cpc_default_phys_base(void) > { > panic("Cannot detect cpc address"); > } > > +static struct clk *__init mt7621_add_sys_clkdev( > + const char *id, unsigned long rate) > +{ > + struct clk *clk; > + int err; > + > + clk = clk_register_fixed_rate(NULL, id, NULL, 0, rate); > + if (IS_ERR(clk)) > + panic("failed to allocate %s clock structure", id); > + > + err = clk_register_clkdev(clk, id, NULL); > + if (err) > + panic("unable to register %s clock device", id); > + > + return clk; > +} > + > void __init ralink_clk_init(void) > { > - int cpu_fdiv = 0; > - int cpu_ffrac = 0; > - int fbdiv = 0; > - u32 clk_sts, syscfg; > - u8 clk_sel = 0, xtal_mode; > - u32 cpu_clk; > + const static u32 prediv_tbl[] = {0, 1, 2, 2}; > + u32 syscfg, xtal_sel, clkcfg, clk_sel, curclk, ffiv, ffrac; > + u32 pll, prediv, fbdiv; > + u32 xtal_clk, cpu_clk, bus_clk; > + > + syscfg = rt_sysc_r32(SYSC_REG_SYSTEM_CONFIG0); > + xtal_sel = (syscfg >> XTAL_MODE_SEL_SHIFT) & XTAL_MODE_SEL_MASK; > > - if ((rt_sysc_r32(SYSC_REG_CPLL_CLKCFG0) & CPU_CLK_SEL) != 0) > - clk_sel = 1; > + clkcfg = rt_sysc_r32(SYSC_REG_CLKCFG0); > + clk_sel = (clkcfg >> CPU_CLK_SEL_SHIFT) & CPU_CLK_SEL_MASK; > + > + curclk = rt_sysc_r32(SYSC_REG_CUR_CLK_STS); > + ffiv = (curclk >> CUR_CPU_FDIV_SHIFT) & CUR_CPU_FDIV_MASK; > + ffrac = (curclk >> CUR_CPU_FFRAC_SHIFT) & CUR_CPU_FFRAC_MASK; > + > + if (xtal_sel <= 2) > + xtal_clk = 20 * 1000 * 1000; > + else if (xtal_sel <= 5) > + xtal_clk = 40 * 1000 * 1000; > + else > + xtal_clk = 25 * 1000 * 1000; > > switch (clk_sel) { > case 0: > - clk_sts = rt_sysc_r32(SYSC_REG_CUR_CLK_STS); > - cpu_fdiv = ((clk_sts >> 8) & 0x1F); > - cpu_ffrac = (clk_sts & 0x1F); > - cpu_clk = (500 * cpu_ffrac / cpu_fdiv) * 1000 * 1000; > + cpu_clk = 500 * 1000 * 1000; > break; > - > case 1: > - fbdiv = ((rt_sysc_r32(0x648) >> 4) & 0x7F) + 1; > - syscfg = rt_sysc_r32(SYSC_REG_SYSCFG); > - xtal_mode = (syscfg >> 6) & 0x7; > - if (xtal_mode >= 6) { > - /* 25Mhz Xtal */ > - cpu_clk = 25 * fbdiv * 1000 * 1000; > - } else if (xtal_mode >= 3) { > - /* 40Mhz Xtal */ > - cpu_clk = 40 * fbdiv * 1000 * 1000; > - } else { > - /* 20Mhz Xtal */ > - cpu_clk = 20 * fbdiv * 1000 * 1000; > - } > + pll = rt_memc_r32(MEMC_REG_CPU_PLL); > + fbdiv = (pll >> CPU_PLL_FBDIV_SHIFT) & CPU_PLL_FBDIV_MASK; > + prediv = (pll >> CPU_PLL_PREDIV_SHIFT) & CPU_PLL_PREDIV_MASK; > + cpu_clk = ((fbdiv + 1) * xtal_clk) >> prediv_tbl[prediv]; > break; > + default: > + cpu_clk = xtal_clk; > } > + > + cpu_clk = cpu_clk / ffiv * ffrac; > + bus_clk = cpu_clk / 4; > + > + clks[MT7621_CLK_CPU] = mt7621_add_sys_clkdev("cpu", cpu_clk); > + clks[MT7621_CLK_BUS] = mt7621_add_sys_clkdev("bus", bus_clk); > + > + pr_info("CPU Clock: %dMHz\n", cpu_clk / 1000000); > + mips_hpt_frequency = cpu_clk / 2; > } > > +static void __init mt7621_clocks_init_dt(struct device_node *np) > +{ > + of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data); > +} > + > +CLK_OF_DECLARE(mt7621_clk, "mediatek,mt7621-pll", mt7621_clocks_init_dt); > + > void __init ralink_of_remap(void) > { > rt_sysc_membase = plat_of_remap_node("mtk,mt7621-sysc"); > diff --git a/arch/mips/ralink/timer-gic.c b/arch/mips/ralink/timer-gic.c > index b5f07d21fcf2..4fed842ae8eb 100644 > --- a/arch/mips/ralink/timer-gic.c > +++ b/arch/mips/ralink/timer-gic.c > @@ -11,14 +11,14 @@ > > #include > #include > -#include > +#include > > #include "common.h" > > void __init plat_time_init(void) > { > ralink_of_remap(); > - > + ralink_clk_init(); > of_clk_init(NULL); > timer_probe(); > } > -- > 2.21.0