diff options
Diffstat (limited to 'drivers/clk')
-rw-r--r-- | drivers/clk/clk.c | 3 | ||||
-rw-r--r-- | drivers/clk/samsung/Makefile | 2 | ||||
-rw-r--r-- | drivers/clk/samsung/clk-cpu.c | 349 | ||||
-rw-r--r-- | drivers/clk/samsung/clk-cpu.h | 73 | ||||
-rw-r--r-- | drivers/clk/samsung/clk-exynos4.c | 24 |
5 files changed, 449 insertions, 2 deletions
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 1cf479b..059e5d2 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1417,6 +1417,9 @@ static void clk_change_rate(struct clk_core *core) if (core->notifier_count && old_rate != core->rate) __clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate); + if (core->flags & CLK_RECALC_NEW_RATES) + (void)clk_calc_new_rates(core, core->new_rate); + /* * Use safe iteration, as change_rate can actually swap parents * for certain clock types. diff --git a/drivers/clk/samsung/Makefile b/drivers/clk/samsung/Makefile index a17683b2..5f6833e 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_EXYNOS4415) += clk-exynos4415.o diff --git a/drivers/clk/samsung/clk-cpu.c b/drivers/clk/samsung/clk-cpu.c new file mode 100644 index 0000000..3a1fe07 --- /dev/null +++ b/drivers/clk/samsung/clk-cpu.c @@ -0,0 +1,349 @@ +/* + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * Author: Thomas Abraham <thomas.ab@samsung.com> + * + * Copyright (c) 2015 Samsung Electronics Co., Ltd. + * Bartlomiej Zolnierkiewicz <b.zolnierkie@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_CPU0 0x400 +#define E4210_DIV_STAT_CPU1 0x404 + +#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_DIV 8 +#define DIV_MASK 7 +#define DIV_MASK_ALL 0xffffffff +#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)); + + if (!(readl(div_reg) & mask)) + return; + + 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) == mux_value) + return; + } while (time_before(jiffies, timeout)); + + if (((readl(mux_reg) >> mux_pos) & MUX_MASK) == mux_value) + return; + + pr_err("%s: re-parenting mux timed-out\n", __func__); +} + +/* common round rate callback useable for all types of CPU clocks */ +static long exynos_cpuclk_round_rate(struct clk_hw *hw, + unsigned long drate, unsigned long *prate) +{ + struct clk *parent = __clk_get_parent(hw->clk); + *prate = __clk_round_rate(parent, drate); + return *prate; +} + +/* common recalc rate callback useable for all types of CPU clocks */ +static unsigned long exynos_cpuclk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + /* + * The CPU clock output (armclk) rate is the same as its parent + * rate. Although there exist certain dividers inside the CPU + * clock block that could be used to divide the parent clock, + * the driver does not make use of them currently, except during + * frequency transitions. + */ + return parent_rate; +} + +static const struct clk_ops exynos_cpuclk_clk_ops = { + .recalc_rate = exynos_cpuclk_recalc_rate, + .round_rate = exynos_cpuclk_round_rate, +}; + +/* + * Helper function to set the 'safe' dividers for the CPU clock. The parameters + * div and mask contain the divider value and the register bit mask of the + * dividers to be programmed. + */ +static void exynos_set_safe_div(void __iomem *base, unsigned long div, + unsigned long mask) +{ + unsigned long div0; + + div0 = readl(base + E4210_DIV_CPU0); + div0 = (div0 & ~mask) | (div & mask); + writel(div0, base + E4210_DIV_CPU0); + wait_until_divider_stable(base + E4210_DIV_STAT_CPU0, mask); +} + +/* handler for pre-rate change notification from parent clock */ +static int exynos_cpuclk_pre_rate_change(struct clk_notifier_data *ndata, + struct exynos_cpuclk *cpuclk, void __iomem *base) +{ + const struct exynos_cpuclk_cfg_data *cfg_data = cpuclk->cfg; + unsigned long alt_prate = clk_get_rate(cpuclk->alt_parent); + unsigned long alt_div = 0, alt_div_mask = DIV_MASK; + unsigned long div0, div1 = 0, mux_reg; + + /* find out the divider values to use for clock data */ + while ((cfg_data->prate * 1000) != ndata->new_rate) { + if (cfg_data->prate == 0) + return -EINVAL; + cfg_data++; + } + + spin_lock(cpuclk->lock); + + /* + * For the selected PLL clock frequency, get the pre-defined divider + * values. If the clock for sclk_hpm is not sourced from apll, then + * the values for DIV_COPY and DIV_HPM dividers need not be set. + */ + div0 = cfg_data->div0; + if (test_bit(CLK_CPU_HAS_DIV1, &cpuclk->flags)) { + div1 = cfg_data->div1; + if (readl(base + E4210_SRC_CPU) & E4210_MUX_HPM_MASK) + div1 = readl(base + E4210_DIV_CPU1) & + (E4210_DIV1_HPM_MASK | E4210_DIV1_COPY_MASK); + } + + /* + * If the old parent clock speed is less than the clock speed of + * the alternate parent, then it should be ensured that at no point + * the armclk speed is more than the old_prate until the dividers are + * set. Also workaround the issue of the dividers being set to lower + * values before the parent clock speed is set to new lower speed + * (this can result in too high speed of armclk output clocks). + */ + if (alt_prate > ndata->old_rate || ndata->old_rate > ndata->new_rate) { + unsigned long tmp_rate = min(ndata->old_rate, ndata->new_rate); + + alt_div = DIV_ROUND_UP(alt_prate, tmp_rate) - 1; + WARN_ON(alt_div >= MAX_DIV); + + if (test_bit(CLK_CPU_NEEDS_DEBUG_ALT_DIV, &cpuclk->flags)) { + /* + * In Exynos4210, ATB clock parent is also mout_core. So + * ATB clock also needs to be mantained at safe speed. + */ + alt_div |= E4210_DIV0_ATB_MASK; + alt_div_mask |= E4210_DIV0_ATB_MASK; + } + exynos_set_safe_div(base, alt_div, alt_div_mask); + div0 |= alt_div; + } + + /* select sclk_mpll as the alternate parent */ + mux_reg = readl(base + E4210_SRC_CPU); + writel(mux_reg | (1 << 16), base + E4210_SRC_CPU); + wait_until_mux_stable(base + E4210_STAT_CPU, 16, 2); + + /* alternate parent is active now. set the dividers */ + writel(div0, base + E4210_DIV_CPU0); + wait_until_divider_stable(base + E4210_DIV_STAT_CPU0, DIV_MASK_ALL); + + if (test_bit(CLK_CPU_HAS_DIV1, &cpuclk->flags)) { + writel(div1, base + E4210_DIV_CPU1); + wait_until_divider_stable(base + E4210_DIV_STAT_CPU1, + DIV_MASK_ALL); + } + + spin_unlock(cpuclk->lock); + return 0; +} + +/* handler for post-rate change notification from parent clock */ +static int exynos_cpuclk_post_rate_change(struct clk_notifier_data *ndata, + struct exynos_cpuclk *cpuclk, void __iomem *base) +{ + const struct exynos_cpuclk_cfg_data *cfg_data = cpuclk->cfg; + unsigned long div = 0, div_mask = DIV_MASK; + unsigned long mux_reg; + + /* find out the divider values to use for clock data */ + if (test_bit(CLK_CPU_NEEDS_DEBUG_ALT_DIV, &cpuclk->flags)) { + while ((cfg_data->prate * 1000) != ndata->new_rate) { + if (cfg_data->prate == 0) + return -EINVAL; + cfg_data++; + } + } + + spin_lock(cpuclk->lock); + + /* select mout_apll as the alternate parent */ + mux_reg = readl(base + E4210_SRC_CPU); + writel(mux_reg & ~(1 << 16), base + E4210_SRC_CPU); + wait_until_mux_stable(base + E4210_STAT_CPU, 16, 1); + + if (test_bit(CLK_CPU_NEEDS_DEBUG_ALT_DIV, &cpuclk->flags)) { + div |= (cfg_data->div0 & E4210_DIV0_ATB_MASK); + div_mask |= E4210_DIV0_ATB_MASK; + } + + exynos_set_safe_div(base, div, div_mask); + spin_unlock(cpuclk->lock); + return 0; +} + +/* + * This notifier function is called for the pre-rate and post-rate change + * notifications of the parent clock of cpuclk. + */ +static int exynos_cpuclk_notifier_cb(struct notifier_block *nb, + unsigned long event, void *data) +{ + struct clk_notifier_data *ndata = data; + struct exynos_cpuclk *cpuclk; + void __iomem *base; + int err = 0; + + cpuclk = container_of(nb, struct exynos_cpuclk, clk_nb); + base = cpuclk->ctrl_base; + + if (event == PRE_RATE_CHANGE) + err = exynos_cpuclk_pre_rate_change(ndata, cpuclk, base); + else if (event == POST_RATE_CHANGE) + err = exynos_cpuclk_post_rate_change(ndata, cpuclk, base); + + return notifier_from_errno(err); +} + +/* helper function to register a CPU clock */ +int __init exynos_register_cpu_clock(struct samsung_clk_provider *ctx, + unsigned int lookup_id, const char *name, const char *parent, + const char *alt_parent, unsigned long offset, + const struct exynos_cpuclk_cfg_data *cfg, + unsigned long num_cfgs, unsigned long flags) +{ + struct exynos_cpuclk *cpuclk; + struct clk_init_data init; + struct clk *clk; + int ret = 0; + + cpuclk = kzalloc(sizeof(*cpuclk), GFP_KERNEL); + if (!cpuclk) + return -ENOMEM; + + init.name = name; + init.flags = CLK_SET_RATE_PARENT; + init.parent_names = &parent; + init.num_parents = 1; + init.ops = &exynos_cpuclk_clk_ops; + + cpuclk->hw.init = &init; + cpuclk->ctrl_base = ctx->reg_base + offset; + cpuclk->lock = &ctx->lock; + cpuclk->flags = flags; + cpuclk->clk_nb.notifier_call = exynos_cpuclk_notifier_cb; + + cpuclk->alt_parent = __clk_lookup(alt_parent); + if (!cpuclk->alt_parent) { + pr_err("%s: could not lookup alternate parent %s\n", + __func__, alt_parent); + ret = -EINVAL; + goto free_cpuclk; + } + + clk = __clk_lookup(parent); + if (!clk) { + pr_err("%s: could not lookup parent clock %s\n", + __func__, parent); + ret = -EINVAL; + goto free_cpuclk; + } + + ret = clk_notifier_register(clk, &cpuclk->clk_nb); + if (ret) { + pr_err("%s: failed to register clock notifier for %s\n", + __func__, name); + goto free_cpuclk; + } + + cpuclk->cfg = kmemdup(cfg, sizeof(*cfg) * num_cfgs, GFP_KERNEL); + if (!cpuclk->cfg) { + pr_err("%s: could not allocate memory for cpuclk data\n", + __func__); + ret = -ENOMEM; + goto unregister_clk_nb; + } + + clk = clk_register(NULL, &cpuclk->hw); + if (IS_ERR(clk)) { + pr_err("%s: could not register cpuclk %s\n", __func__, name); + ret = PTR_ERR(clk); + goto free_cpuclk_data; + } + + samsung_clk_add_lookup(ctx, clk, lookup_id); + return 0; + +free_cpuclk_data: + kfree(cpuclk->cfg); +unregister_clk_nb: + clk_notifier_unregister(__clk_lookup(parent), &cpuclk->clk_nb); +free_cpuclk: + kfree(cpuclk); + return ret; +} diff --git a/drivers/clk/samsung/clk-cpu.h b/drivers/clk/samsung/clk-cpu.h new file mode 100644 index 0000000..37874d3 --- /dev/null +++ b/drivers/clk/samsung/clk-cpu.h @@ -0,0 +1,73 @@ +/* + * Copyright (c) 2014 Samsung Electronics Co., Ltd. + * + * 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. + * + * Common Clock Framework support for all PLL's in Samsung platforms +*/ + +#ifndef __SAMSUNG_CLK_CPU_H +#define __SAMSUNG_CLK_CPU_H + +#include "clk.h" + +/** + * struct exynos_cpuclk_data: config data to setup cpu clocks. + * @prate: frequency of the primary parent clock (in KHz). + * @div0: value to be programmed in the div_cpu0 register. + * @div1: value to be programmed in the div_cpu1 register. + * + * This structure holds the divider configuration data for dividers in the CPU + * clock domain. The parent frequency at which these divider values are valid is + * specified in @prate. The @prate is the frequency of the primary parent clock. + * For CPU clock domains that do not have a DIV1 register, the @div1 member + * value is not used. + */ +struct exynos_cpuclk_cfg_data { + unsigned long prate; + unsigned long div0; + unsigned long div1; +}; + +/** + * struct exynos_cpuclk: information about clock supplied to a CPU core. + * @hw: handle between CCF and CPU clock. + * @alt_parent: alternate parent clock to use when switching the speed + * of the primary parent clock. + * @ctrl_base: base address of the clock controller. + * @lock: cpu clock domain register access lock. + * @cfg: cpu clock rate configuration data. + * @num_cfgs: number of array elements in @cfg array. + * @clk_nb: clock notifier registered for changes in clock speed of the + * primary parent clock. + * @flags: configuration flags for the CPU clock. + * + * This structure holds information required for programming the CPU clock for + * various clock speeds. + */ +struct exynos_cpuclk { + struct clk_hw hw; + struct clk *alt_parent; + void __iomem *ctrl_base; + spinlock_t *lock; + const struct exynos_cpuclk_cfg_data *cfg; + const unsigned long num_cfgs; + struct notifier_block clk_nb; + unsigned long flags; + +/* The CPU clock registers has DIV1 configuration register */ +#define CLK_CPU_HAS_DIV1 (1 << 0) +/* When ALT parent is active, debug clocks need safe divider values */ +#define CLK_CPU_NEEDS_DEBUG_ALT_DIV (1 << 1) +}; + +extern int __init exynos_register_cpu_clock(struct samsung_clk_provider *ctx, + unsigned int lookup_id, const char *name, + const char *parent, const char *alt_parent, + unsigned long offset, + const struct exynos_cpuclk_cfg_data *cfg, + unsigned long num_cfgs, unsigned long flags); + +#endif /* __SAMSUNG_CLK_CPU_H */ diff --git a/drivers/clk/samsung/clk-exynos4.c b/drivers/clk/samsung/clk-exynos4.c index 714d6ba..cae2c04 100644 --- a/drivers/clk/samsung/clk-exynos4.c +++ b/drivers/clk/samsung/clk-exynos4.c @@ -19,6 +19,7 @@ #include <linux/syscore_ops.h> #include "clk.h" +#include "clk-cpu.h" /* Exynos4 clock controller register offsets */ #define SRC_LEFTBUS 0x4200 @@ -534,7 +535,8 @@ static struct samsung_fixed_factor_clock exynos4x12_fixed_factor_clks[] __initda /* list of mux clocks supported in all exynos4 soc's */ static struct samsung_mux_clock exynos4_mux_clks[] __initdata = { MUX_FA(CLK_MOUT_APLL, "mout_apll", mout_apll_p, SRC_CPU, 0, 1, - CLK_SET_RATE_PARENT, 0, "mout_apll"), + CLK_SET_RATE_PARENT | CLK_RECALC_NEW_RATES, 0, + "mout_apll"), MUX(CLK_MOUT_HDMI, "mout_hdmi", mout_hdmi_p, SRC_TV, 0, 1), MUX(0, "mout_mfc1", sclk_evpll_p, SRC_MFC, 4, 1), MUX(0, "mout_mfc", mout_mfc_p, SRC_MFC, 8, 1), @@ -1378,6 +1380,22 @@ static void __init exynos4x12_core_down_clock(void) __raw_writel(0x0, reg_base + E4X12_PWR_CTRL2); } +#define E4210_CPU_DIV0(apll, pclk_dbg, atb, periph, corem1, corem0) \ + (((apll) << 24) | ((pclk_dbg) << 20) | ((atb) << 16) | \ + ((periph) << 12) | ((corem1) << 8) | ((corem0) << 4)) +#define E4210_CPU_DIV1(hpm, copy) \ + (((hpm) << 4) | ((copy) << 0)) + +static const struct exynos_cpuclk_cfg_data e4210_armclk_d[] __initconst = { + { 1200000, E4210_CPU_DIV0(7, 1, 4, 3, 7, 3), E4210_CPU_DIV1(0, 5), }, + { 1000000, E4210_CPU_DIV0(7, 1, 4, 3, 7, 3), E4210_CPU_DIV1(0, 4), }, + { 800000, E4210_CPU_DIV0(7, 1, 3, 3, 7, 3), E4210_CPU_DIV1(0, 3), }, + { 500000, E4210_CPU_DIV0(7, 1, 3, 3, 7, 3), E4210_CPU_DIV1(0, 3), }, + { 400000, E4210_CPU_DIV0(7, 1, 3, 3, 7, 3), E4210_CPU_DIV1(0, 3), }, + { 200000, E4210_CPU_DIV0(0, 1, 1, 1, 3, 1), E4210_CPU_DIV1(0, 3), }, + { 0 }, +}; + /* register exynos4 clocks */ static void __init exynos4_clk_init(struct device_node *np, enum exynos4_soc soc) @@ -1455,6 +1473,10 @@ static void __init exynos4_clk_init(struct device_node *np, samsung_clk_register_fixed_factor(ctx, exynos4210_fixed_factor_clks, ARRAY_SIZE(exynos4210_fixed_factor_clks)); + exynos_register_cpu_clock(ctx, CLK_ARM_CLK, "armclk", + mout_core_p4210[0], mout_core_p4210[1], 0x14200, + e4210_armclk_d, ARRAY_SIZE(e4210_armclk_d), + CLK_CPU_NEEDS_DEBUG_ALT_DIV | CLK_CPU_HAS_DIV1); } else { samsung_clk_register_mux(ctx, exynos4x12_mux_clks, ARRAY_SIZE(exynos4x12_mux_clks)); |