Re: [PATCH v9 1/6] clk: samsung: add infrastructure to register cpu clocks
On Tue, Sep 2, 2014 at 3:59 AM, Mike Turquette mturque...@linaro.org wrote: Quoting Thomas Abraham (2014-07-30 01:07:38) The CPU clock provider supplies the clock to the CPU clock domain. The composition and organization of the CPU clock provider could vary among Exynos SoCs. A CPU clock provider can be composed of clock mux, dividers and gates. This patch defines a new clock type for CPU clock provider and adds infrastructure to register the CPU clock providers for Samsung platforms. Signed-off-by: Thomas Abraham thomas...@samsung.com Reviewed-by: Tomasz Figa t.f...@samsung.com Acked-by: Mike Turquette mturque...@linaro.org Thank you Mike. Regards, Thomas. --- drivers/clk/samsung/Makefile |2 +- drivers/clk/samsung/clk-cpu.c | 335 + drivers/clk/samsung/clk-cpu.h | 91 +++ 3 files changed, 427 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/samsung/clk-cpu.c create mode 100644 drivers/clk/samsung/clk-cpu.h diff --git a/drivers/clk/samsung/Makefile b/drivers/clk/samsung/Makefile index 6fb4bc6..8909c93 100644 --- a/drivers/clk/samsung/Makefile +++ b/drivers/clk/samsung/Makefile @@ -2,7 +2,7 @@ # Samsung Clock specific Makefile # -obj-$(CONFIG_COMMON_CLK) += clk.o clk-pll.o +obj-$(CONFIG_COMMON_CLK) += clk.o clk-pll.o clk-cpu.o obj-$(CONFIG_SOC_EXYNOS3250) += clk-exynos3250.o obj-$(CONFIG_ARCH_EXYNOS4) += clk-exynos4.o obj-$(CONFIG_SOC_EXYNOS5250) += clk-exynos5250.o diff --git a/drivers/clk/samsung/clk-cpu.c b/drivers/clk/samsung/clk-cpu.c new file mode 100644 index 000..009a21b --- /dev/null +++ b/drivers/clk/samsung/clk-cpu.c @@ -0,0 +1,335 @@ +/* + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Thomas Abraham thomas...@samsung.com + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This file contains the utility function to register CPU clock for Samsung + * Exynos platforms. A CPU clock is defined as a clock supplied to a CPU or a + * group of CPUs. The CPU clock is typically derived from a hierarchy of clock + * blocks which includes mux and divider blocks. There are a number of other + * auxiliary clocks supplied to the CPU domain such as the debug blocks and AXI + * clock for CPU domain. The rates of these auxiliary clocks are related to the + * CPU clock rate and this relation is usually specified in the hardware manual + * of the SoC or supplied after the SoC characterization. + * + * The below implementation of the CPU clock allows the rate changes of the CPU + * clock and the corresponding rate changes of the auxillary clocks of the CPU + * domain. The platform clock driver provides a clock register configuration + * for each configurable rate which is then used to program the clock hardware + * registers to acheive a fast co-oridinated rate change for all the CPU domain + * clocks. + * + * On a rate change request for the CPU clock, the rate change is propagated + * upto the PLL supplying the clock to the CPU domain clock blocks. While the + * CPU domain PLL is reconfigured, the CPU domain clocks are driven using an + * alternate clock source. If required, the alternate clock source is divided + * down in order to keep the output clock rate within the previous OPP limits. +*/ + +#include linux/errno.h +#include clk-cpu.h + +#define E4210_SRC_CPU 0x0 +#define E4210_STAT_CPU 0x200 +#define E4210_DIV_CPU0 0x300 +#define E4210_DIV_CPU1 0x304 +#define E4210_DIV_STAT_CPU00x400 +#define E4210_DIV_STAT_CPU10x404 + +#define E4210_DIV0_RATIO0_MASK 0x7 +#define E4210_DIV1_HPM_MASK(0x7 4) +#define E4210_DIV1_COPY_MASK (0x7 0) +#define E4210_MUX_HPM_MASK (1 20) +#define E4210_DIV0_ATB_SHIFT 16 +#define E4210_DIV0_ATB_MASK(DIV_MASK E4210_DIV0_ATB_SHIFT) + +#define MAX_DIV8 +#define DIV_MASK 7 +#define DIV_MASK_ALL 0x +#define MUX_MASK 7 + +/* + * Helper function to wait until divider(s) have stabilized after the divider + * value has changed. + */ +static void wait_until_divider_stable(void __iomem *div_reg, unsigned long mask) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(10); + + do { + if (!(readl(div_reg) mask)) + return; + } while (time_before(jiffies, timeout)); + + pr_err(%s: timeout in divider stablization\n, __func__); +} + +/* + * Helper function to wait until mux has stabilized after the mux selection + * value was changed. + */ +static void wait_until_mux_stable(void __iomem *mux_reg, u32 mux_pos, + unsigned long mux_value) +{ + unsigned long
Re: [PATCH v9 1/6] clk: samsung: add infrastructure to register cpu clocks
Quoting Thomas Abraham (2014-07-30 01:07:38) The CPU clock provider supplies the clock to the CPU clock domain. The composition and organization of the CPU clock provider could vary among Exynos SoCs. A CPU clock provider can be composed of clock mux, dividers and gates. This patch defines a new clock type for CPU clock provider and adds infrastructure to register the CPU clock providers for Samsung platforms. Signed-off-by: Thomas Abraham thomas...@samsung.com Reviewed-by: Tomasz Figa t.f...@samsung.com Acked-by: Mike Turquette mturque...@linaro.org --- drivers/clk/samsung/Makefile |2 +- drivers/clk/samsung/clk-cpu.c | 335 + drivers/clk/samsung/clk-cpu.h | 91 +++ 3 files changed, 427 insertions(+), 1 deletion(-) create mode 100644 drivers/clk/samsung/clk-cpu.c create mode 100644 drivers/clk/samsung/clk-cpu.h diff --git a/drivers/clk/samsung/Makefile b/drivers/clk/samsung/Makefile index 6fb4bc6..8909c93 100644 --- a/drivers/clk/samsung/Makefile +++ b/drivers/clk/samsung/Makefile @@ -2,7 +2,7 @@ # Samsung Clock specific Makefile # -obj-$(CONFIG_COMMON_CLK) += clk.o clk-pll.o +obj-$(CONFIG_COMMON_CLK) += clk.o clk-pll.o clk-cpu.o obj-$(CONFIG_SOC_EXYNOS3250) += clk-exynos3250.o obj-$(CONFIG_ARCH_EXYNOS4) += clk-exynos4.o obj-$(CONFIG_SOC_EXYNOS5250) += clk-exynos5250.o diff --git a/drivers/clk/samsung/clk-cpu.c b/drivers/clk/samsung/clk-cpu.c new file mode 100644 index 000..009a21b --- /dev/null +++ b/drivers/clk/samsung/clk-cpu.c @@ -0,0 +1,335 @@ +/* + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Thomas Abraham thomas...@samsung.com + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This file contains the utility function to register CPU clock for Samsung + * Exynos platforms. A CPU clock is defined as a clock supplied to a CPU or a + * group of CPUs. The CPU clock is typically derived from a hierarchy of clock + * blocks which includes mux and divider blocks. There are a number of other + * auxiliary clocks supplied to the CPU domain such as the debug blocks and AXI + * clock for CPU domain. The rates of these auxiliary clocks are related to the + * CPU clock rate and this relation is usually specified in the hardware manual + * of the SoC or supplied after the SoC characterization. + * + * The below implementation of the CPU clock allows the rate changes of the CPU + * clock and the corresponding rate changes of the auxillary clocks of the CPU + * domain. The platform clock driver provides a clock register configuration + * for each configurable rate which is then used to program the clock hardware + * registers to acheive a fast co-oridinated rate change for all the CPU domain + * clocks. + * + * On a rate change request for the CPU clock, the rate change is propagated + * upto the PLL supplying the clock to the CPU domain clock blocks. While the + * CPU domain PLL is reconfigured, the CPU domain clocks are driven using an + * alternate clock source. If required, the alternate clock source is divided + * down in order to keep the output clock rate within the previous OPP limits. +*/ + +#include linux/errno.h +#include clk-cpu.h + +#define E4210_SRC_CPU 0x0 +#define E4210_STAT_CPU 0x200 +#define E4210_DIV_CPU0 0x300 +#define E4210_DIV_CPU1 0x304 +#define E4210_DIV_STAT_CPU00x400 +#define E4210_DIV_STAT_CPU10x404 + +#define E4210_DIV0_RATIO0_MASK 0x7 +#define E4210_DIV1_HPM_MASK(0x7 4) +#define E4210_DIV1_COPY_MASK (0x7 0) +#define E4210_MUX_HPM_MASK (1 20) +#define E4210_DIV0_ATB_SHIFT 16 +#define E4210_DIV0_ATB_MASK(DIV_MASK E4210_DIV0_ATB_SHIFT) + +#define MAX_DIV8 +#define DIV_MASK 7 +#define DIV_MASK_ALL 0x +#define MUX_MASK 7 + +/* + * Helper function to wait until divider(s) have stabilized after the divider + * value has changed. + */ +static void wait_until_divider_stable(void __iomem *div_reg, unsigned long mask) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(10); + + do { + if (!(readl(div_reg) mask)) + return; + } while (time_before(jiffies, timeout)); + + pr_err(%s: timeout in divider stablization\n, __func__); +} + +/* + * Helper function to wait until mux has stabilized after the mux selection + * value was changed. + */ +static void wait_until_mux_stable(void __iomem *mux_reg, u32 mux_pos, + unsigned long mux_value) +{ + unsigned long timeout = jiffies + msecs_to_jiffies(10); + + do { + if (((readl(mux_reg) mux_pos) MUX_MASK) ==