diff options
author | Emilio López <emilio@elopez.com.ar> | 2013-02-25 14:44:26 (GMT) |
---|---|---|
committer | Mike Turquette <mturquette@linaro.org> | 2013-03-27 15:35:34 (GMT) |
commit | e874a6697710f52fa8ab29487a99034d5d96fdcc (patch) | |
tree | 1743abc90ee2d604fe5f8a0f4b69f171179ced31 /drivers/clk | |
parent | b54891685162e09c4292cd38f067ca118604353c (diff) | |
download | linux-fsl-qoriq-e874a6697710f52fa8ab29487a99034d5d96fdcc.tar.xz |
clk: arm: sunxi: Add a new clock driver for sunxi SOCs
This commit implements the base CPU clocks for sunxi devices. It has
been tested using a slightly modified cpufreq driver from the
linux-sunxi 3.0 tree.
Additionally, document the new bindings introduced by this patch.
Idling:
/ # cat /sys/kernel/debug/clk/clk_summary
clock enable_cnt prepare_cnt rate
---------------------------------------------------------------------
osc32k 0 0 32768
osc24M_fixed 0 0 24000000
osc24M 0 0 24000000
apb1_mux 0 0 24000000
apb1 0 0 24000000
pll1 0 0 60000000
cpu 0 0 60000000
axi 0 0 60000000
ahb 0 0 60000000
apb0 0 0 30000000
dummy 0 0 0
After "yes >/dev/null &":
/ # cat /sys/kernel/debug/clk/clk_summary
clock enable_cnt prepare_cnt rate
---------------------------------------------------------------------
osc32k 0 0 32768
osc24M_fixed 0 0 24000000
osc24M 0 0 24000000
apb1_mux 0 0 24000000
apb1 0 0 24000000
pll1 0 0 1008000000
cpu 0 0 1008000000
axi 0 0 336000000
ahb 0 0 168000000
apb0 0 0 84000000
dummy 0 0 0
Signed-off-by: Emilio López <emilio@elopez.com.ar>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
Diffstat (limited to 'drivers/clk')
-rw-r--r-- | drivers/clk/Makefile | 1 | ||||
-rw-r--r-- | drivers/clk/sunxi/Makefile | 5 | ||||
-rw-r--r-- | drivers/clk/sunxi/clk-factors.c | 180 | ||||
-rw-r--r-- | drivers/clk/sunxi/clk-factors.h | 27 | ||||
-rw-r--r-- | drivers/clk/sunxi/clk-sunxi.c | 362 |
5 files changed, 575 insertions, 0 deletions
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index 41cb123..79e98e4 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -24,6 +24,7 @@ ifeq ($(CONFIG_COMMON_CLK), y) obj-$(CONFIG_ARCH_MMP) += mmp/ endif obj-$(CONFIG_MACH_LOONGSON1) += clk-ls1x.o +obj-$(CONFIG_ARCH_SUNXI) += sunxi/ obj-$(CONFIG_ARCH_U8500) += ux500/ obj-$(CONFIG_ARCH_VT8500) += clk-vt8500.o obj-$(CONFIG_ARCH_ZYNQ) += clk-zynq.o diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile new file mode 100644 index 0000000..b5bac91 --- /dev/null +++ b/drivers/clk/sunxi/Makefile @@ -0,0 +1,5 @@ +# +# Makefile for sunxi specific clk +# + +obj-y += clk-sunxi.o clk-factors.o diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c new file mode 100644 index 0000000..88523f9 --- /dev/null +++ b/drivers/clk/sunxi/clk-factors.c @@ -0,0 +1,180 @@ +/* + * Copyright (C) 2013 Emilio López <emilio@elopez.com.ar> + * + * 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. + * + * Adjustable factor-based clock implementation + */ + +#include <linux/clk-provider.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/err.h> +#include <linux/string.h> + +#include <linux/delay.h> + +#include "clk-factors.h" + +/* + * DOC: basic adjustable factor-based clock that cannot gate + * + * Traits of this clock: + * prepare - clk_prepare only ensures that parents are prepared + * enable - clk_enable only ensures that parents are enabled + * rate - rate is adjustable. + * clk->rate = (parent->rate * N * (K + 1) >> P) / (M + 1) + * parent - fixed parent. No clk_set_parent support + */ + +struct clk_factors { + struct clk_hw hw; + void __iomem *reg; + struct clk_factors_config *config; + void (*get_factors) (u32 *rate, u32 parent, u8 *n, u8 *k, u8 *m, u8 *p); + spinlock_t *lock; +}; + +#define to_clk_factors(_hw) container_of(_hw, struct clk_factors, hw) + +#define SETMASK(len, pos) (((-1U) >> (31-len)) << (pos)) +#define CLRMASK(len, pos) (~(SETMASK(len, pos))) +#define FACTOR_GET(bit, len, reg) (((reg) & SETMASK(len, bit)) >> (bit)) + +#define FACTOR_SET(bit, len, reg, val) \ + (((reg) & CLRMASK(len, bit)) | (val << (bit))) + +static unsigned long clk_factors_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + u8 n = 1, k = 0, p = 0, m = 0; + u32 reg; + unsigned long rate; + struct clk_factors *factors = to_clk_factors(hw); + struct clk_factors_config *config = factors->config; + + /* Fetch the register value */ + reg = readl(factors->reg); + + /* Get each individual factor if applicable */ + if (config->nwidth != SUNXI_FACTORS_NOT_APPLICABLE) + n = FACTOR_GET(config->nshift, config->nwidth, reg); + if (config->kwidth != SUNXI_FACTORS_NOT_APPLICABLE) + k = FACTOR_GET(config->kshift, config->kwidth, reg); + if (config->mwidth != SUNXI_FACTORS_NOT_APPLICABLE) + m = FACTOR_GET(config->mshift, config->mwidth, reg); + if (config->pwidth != SUNXI_FACTORS_NOT_APPLICABLE) + p = FACTOR_GET(config->pshift, config->pwidth, reg); + + /* Calculate the rate */ + rate = (parent_rate * n * (k + 1) >> p) / (m + 1); + + return rate; +} + +static long clk_factors_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct clk_factors *factors = to_clk_factors(hw); + factors->get_factors((u32 *)&rate, (u32)*parent_rate, + NULL, NULL, NULL, NULL); + + return rate; +} + +static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + u8 n, k, m, p; + u32 reg; + struct clk_factors *factors = to_clk_factors(hw); + struct clk_factors_config *config = factors->config; + unsigned long flags = 0; + + factors->get_factors((u32 *)&rate, (u32)parent_rate, &n, &k, &m, &p); + + if (factors->lock) + spin_lock_irqsave(factors->lock, flags); + + /* Fetch the register value */ + reg = readl(factors->reg); + + /* Set up the new factors - macros do not do anything if width is 0 */ + reg = FACTOR_SET(config->nshift, config->nwidth, reg, n); + reg = FACTOR_SET(config->kshift, config->kwidth, reg, k); + reg = FACTOR_SET(config->mshift, config->mwidth, reg, m); + reg = FACTOR_SET(config->pshift, config->pwidth, reg, p); + + /* Apply them now */ + writel(reg, factors->reg); + + /* delay 500us so pll stabilizes */ + __delay((rate >> 20) * 500 / 2); + + if (factors->lock) + spin_unlock_irqrestore(factors->lock, flags); + + return 0; +} + +static const struct clk_ops clk_factors_ops = { + .recalc_rate = clk_factors_recalc_rate, + .round_rate = clk_factors_round_rate, + .set_rate = clk_factors_set_rate, +}; + +/** + * clk_register_factors - register a factors clock with + * the clock framework + * @dev: device registering this clock + * @name: name of this clock + * @parent_name: name of clock's parent + * @flags: framework-specific flags + * @reg: register address to adjust factors + * @config: shift and width of factors n, k, m and p + * @get_factors: function to calculate the factors for a given frequency + * @lock: shared register lock for this clock + */ +struct clk *clk_register_factors(struct device *dev, const char *name, + const char *parent_name, + unsigned long flags, void __iomem *reg, + struct clk_factors_config *config, + void (*get_factors)(u32 *rate, u32 parent, + u8 *n, u8 *k, u8 *m, u8 *p), + spinlock_t *lock) +{ + struct clk_factors *factors; + struct clk *clk; + struct clk_init_data init; + + /* allocate the factors */ + factors = kzalloc(sizeof(struct clk_factors), GFP_KERNEL); + if (!factors) { + pr_err("%s: could not allocate factors clk\n", __func__); + return ERR_PTR(-ENOMEM); + } + + init.name = name; + init.ops = &clk_factors_ops; + init.flags = flags; + init.parent_names = (parent_name ? &parent_name : NULL); + init.num_parents = (parent_name ? 1 : 0); + + /* struct clk_factors assignments */ + factors->reg = reg; + factors->config = config; + factors->lock = lock; + factors->hw.init = &init; + factors->get_factors = get_factors; + + /* register the clock */ + clk = clk_register(dev, &factors->hw); + + if (IS_ERR(clk)) + kfree(factors); + + return clk; +} diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h new file mode 100644 index 0000000..f49851c --- /dev/null +++ b/drivers/clk/sunxi/clk-factors.h @@ -0,0 +1,27 @@ +#ifndef __MACH_SUNXI_CLK_FACTORS_H +#define __MACH_SUNXI_CLK_FACTORS_H + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> + +#define SUNXI_FACTORS_NOT_APPLICABLE (0) + +struct clk_factors_config { + u8 nshift; + u8 nwidth; + u8 kshift; + u8 kwidth; + u8 mshift; + u8 mwidth; + u8 pshift; + u8 pwidth; +}; + +struct clk *clk_register_factors(struct device *dev, const char *name, + const char *parent_name, + unsigned long flags, void __iomem *reg, + struct clk_factors_config *config, + void (*get_factors) (u32 *rate, u32 parent_rate, + u8 *n, u8 *k, u8 *m, u8 *p), + spinlock_t *lock); +#endif diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c new file mode 100644 index 0000000..d4ad1c2 --- /dev/null +++ b/drivers/clk/sunxi/clk-sunxi.c @@ -0,0 +1,362 @@ +/* + * Copyright 2013 Emilio López + * + * Emilio López <emilio@elopez.com.ar> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/clk/sunxi.h> +#include <linux/of.h> +#include <linux/of_address.h> + +#include "clk-factors.h" + +static DEFINE_SPINLOCK(clk_lock); + +/** + * sunxi_osc_clk_setup() - Setup function for gatable oscillator + */ + +#define SUNXI_OSC24M_GATE 0 + +static void __init sunxi_osc_clk_setup(struct device_node *node) +{ + struct clk *clk; + const char *clk_name = node->name; + const char *parent; + void *reg; + + reg = of_iomap(node, 0); + + parent = of_clk_get_parent_name(node, 0); + + clk = clk_register_gate(NULL, clk_name, parent, CLK_IGNORE_UNUSED, + reg, SUNXI_OSC24M_GATE, 0, &clk_lock); + + if (clk) { + of_clk_add_provider(node, of_clk_src_simple_get, clk); + clk_register_clkdev(clk, clk_name, NULL); + } +} + + + +/** + * sunxi_get_pll1_factors() - calculates n, k, m, p factors for PLL1 + * PLL1 rate is calculated as follows + * rate = (parent_rate * n * (k + 1) >> p) / (m + 1); + * parent_rate is always 24Mhz + */ + +static void sunxi_get_pll1_factors(u32 *freq, u32 parent_rate, + u8 *n, u8 *k, u8 *m, u8 *p) +{ + u8 div; + + /* Normalize value to a 6M multiple */ + div = *freq / 6000000; + *freq = 6000000 * div; + + /* we were called to round the frequency, we can now return */ + if (n == NULL) + return; + + /* m is always zero for pll1 */ + *m = 0; + + /* k is 1 only on these cases */ + if (*freq >= 768000000 || *freq == 42000000 || *freq == 54000000) + *k = 1; + else + *k = 0; + + /* p will be 3 for divs under 10 */ + if (div < 10) + *p = 3; + + /* p will be 2 for divs between 10 - 20 and odd divs under 32 */ + else if (div < 20 || (div < 32 && (div & 1))) + *p = 2; + + /* p will be 1 for even divs under 32, divs under 40 and odd pairs + * of divs between 40-62 */ + else if (div < 40 || (div < 64 && (div & 2))) + *p = 1; + + /* any other entries have p = 0 */ + else + *p = 0; + + /* calculate a suitable n based on k and p */ + div <<= *p; + div /= (*k + 1); + *n = div / 4; +} + + + +/** + * sunxi_get_apb1_factors() - calculates m, p factors for APB1 + * APB1 rate is calculated as follows + * rate = (parent_rate >> p) / (m + 1); + */ + +static void sunxi_get_apb1_factors(u32 *freq, u32 parent_rate, + u8 *n, u8 *k, u8 *m, u8 *p) +{ + u8 calcm, calcp; + + if (parent_rate < *freq) + *freq = parent_rate; + + parent_rate = (parent_rate + (*freq - 1)) / *freq; + + /* Invalid rate! */ + if (parent_rate > 32) + return; + + if (parent_rate <= 4) + calcp = 0; + else if (parent_rate <= 8) + calcp = 1; + else if (parent_rate <= 16) + calcp = 2; + else + calcp = 3; + + calcm = (parent_rate >> calcp) - 1; + + *freq = (parent_rate >> calcp) / (calcm + 1); + + /* we were called to round the frequency, we can now return */ + if (n == NULL) + return; + + *m = calcm; + *p = calcp; +} + + + +/** + * sunxi_factors_clk_setup() - Setup function for factor clocks + */ + +struct factors_data { + struct clk_factors_config *table; + void (*getter) (u32 *rate, u32 parent_rate, u8 *n, u8 *k, u8 *m, u8 *p); +}; + +static struct clk_factors_config pll1_config = { + .nshift = 8, + .nwidth = 5, + .kshift = 4, + .kwidth = 2, + .mshift = 0, + .mwidth = 2, + .pshift = 16, + .pwidth = 2, +}; + +static struct clk_factors_config apb1_config = { + .mshift = 0, + .mwidth = 5, + .pshift = 16, + .pwidth = 2, +}; + +static const __initconst struct factors_data pll1_data = { + .table = &pll1_config, + .getter = sunxi_get_pll1_factors, +}; + +static const __initconst struct factors_data apb1_data = { + .table = &apb1_config, + .getter = sunxi_get_apb1_factors, +}; + +static void __init sunxi_factors_clk_setup(struct device_node *node, + struct factors_data *data) +{ + struct clk *clk; + const char *clk_name = node->name; + const char *parent; + void *reg; + + reg = of_iomap(node, 0); + + parent = of_clk_get_parent_name(node, 0); + + clk = clk_register_factors(NULL, clk_name, parent, CLK_IGNORE_UNUSED, + reg, data->table, data->getter, &clk_lock); + + if (clk) { + of_clk_add_provider(node, of_clk_src_simple_get, clk); + clk_register_clkdev(clk, clk_name, NULL); + } +} + + + +/** + * sunxi_mux_clk_setup() - Setup function for muxes + */ + +#define SUNXI_MUX_GATE_WIDTH 2 + +struct mux_data { + u8 shift; +}; + +static const __initconst struct mux_data cpu_data = { + .shift = 16, +}; + +static const __initconst struct mux_data apb1_mux_data = { + .shift = 24, +}; + +static void __init sunxi_mux_clk_setup(struct device_node *node, + struct mux_data *data) +{ + struct clk *clk; + const char *clk_name = node->name; + const char **parents = kmalloc(sizeof(char *) * 5, GFP_KERNEL); + void *reg; + int i = 0; + + reg = of_iomap(node, 0); + + while (i < 5 && (parents[i] = of_clk_get_parent_name(node, i)) != NULL) + i++; + + clk = clk_register_mux(NULL, clk_name, parents, i, 0, reg, + data->shift, SUNXI_MUX_GATE_WIDTH, + 0, &clk_lock); + + if (clk) { + of_clk_add_provider(node, of_clk_src_simple_get, clk); + clk_register_clkdev(clk, clk_name, NULL); + } +} + + + +/** + * sunxi_divider_clk_setup() - Setup function for simple divider clocks + */ + +#define SUNXI_DIVISOR_WIDTH 2 + +struct div_data { + u8 shift; + u8 pow; +}; + +static const __initconst struct div_data axi_data = { + .shift = 0, + .pow = 0, +}; + +static const __initconst struct div_data ahb_data = { + .shift = 4, + .pow = 1, +}; + +static const __initconst struct div_data apb0_data = { + .shift = 8, + .pow = 1, +}; + +static void __init sunxi_divider_clk_setup(struct device_node *node, + struct div_data *data) +{ + struct clk *clk; + const char *clk_name = node->name; + const char *clk_parent; + void *reg; + + reg = of_iomap(node, 0); + + clk_parent = of_clk_get_parent_name(node, 0); + + clk = clk_register_divider(NULL, clk_name, clk_parent, 0, + reg, data->shift, SUNXI_DIVISOR_WIDTH, + data->pow ? CLK_DIVIDER_POWER_OF_TWO : 0, + &clk_lock); + if (clk) { + of_clk_add_provider(node, of_clk_src_simple_get, clk); + clk_register_clkdev(clk, clk_name, NULL); + } +} + + +/* Matches for of_clk_init */ +static const __initconst struct of_device_id clk_match[] = { + {.compatible = "fixed-clock", .data = of_fixed_clk_setup,}, + {.compatible = "allwinner,sunxi-osc-clk", .data = sunxi_osc_clk_setup,}, + {} +}; + +/* Matches for factors clocks */ +static const __initconst struct of_device_id clk_factors_match[] = { + {.compatible = "allwinner,sunxi-pll1-clk", .data = &pll1_data,}, + {.compatible = "allwinner,sunxi-apb1-clk", .data = &apb1_data,}, + {} +}; + +/* Matches for divider clocks */ +static const __initconst struct of_device_id clk_div_match[] = { + {.compatible = "allwinner,sunxi-axi-clk", .data = &axi_data,}, + {.compatible = "allwinner,sunxi-ahb-clk", .data = &ahb_data,}, + {.compatible = "allwinner,sunxi-apb0-clk", .data = &apb0_data,}, + {} +}; + +/* Matches for mux clocks */ +static const __initconst struct of_device_id clk_mux_match[] = { + {.compatible = "allwinner,sunxi-cpu-clk", .data = &cpu_data,}, + {.compatible = "allwinner,sunxi-apb1-mux-clk", .data = &apb1_mux_data,}, + {} +}; + +static void __init of_sunxi_table_clock_setup(const struct of_device_id *clk_match, + void *function) +{ + struct device_node *np; + const struct div_data *data; + const struct of_device_id *match; + void (*setup_function)(struct device_node *, const void *) = function; + + for_each_matching_node(np, clk_match) { + match = of_match_node(clk_match, np); + data = match->data; + setup_function(np, data); + } +} + +void __init sunxi_init_clocks(void) +{ + /* Register all the simple sunxi clocks on DT */ + of_clk_init(clk_match); + + /* Register factor clocks */ + of_sunxi_table_clock_setup(clk_factors_match, sunxi_factors_clk_setup); + + /* Register divider clocks */ + of_sunxi_table_clock_setup(clk_div_match, sunxi_divider_clk_setup); + + /* Register mux clocks */ + of_sunxi_table_clock_setup(clk_mux_match, sunxi_mux_clk_setup); +} |