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>
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);
+}