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authorLucas Stach <l.stach@pengutronix.de>2014-09-26 15:41:01 +0200
committerShawn Guo <shawn.guo@linaro.org>2014-09-29 19:55:39 +0800
commitd3234aa148e93427df027321a359dcb0c0b9ba06 (patch)
treeb60a3ce0330f03e107847dfccdd2f8d9e9b57b45 /arch
parent48336708c78cc5a1e3a93bcbb4b380b9ecf7df43 (diff)
ARM: imx: add CPU clock type
This implements a virtual clock used to abstract away all the steps needed in order to change the ARM clock, so we don't have to push all this clock handling into the cpufreq driver. While it will be used for i.MX53 at first it is generic enough to be used on i.MX6 later on. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mach-imx/Makefile2
-rw-r--r--arch/arm/mach-imx/clk-cpu.c107
-rw-r--r--arch/arm/mach-imx/clk.h4
3 files changed, 112 insertions, 1 deletions
diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 6e4fcd8339cd..b8580f363e51 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -12,7 +12,7 @@ obj-$(CONFIG_SOC_IMX31) += mm-imx3.o cpu-imx31.o clk-imx31.o iomux-imx31.o ehci-
obj-$(CONFIG_SOC_IMX35) += mm-imx3.o cpu-imx35.o clk-imx35.o ehci-imx35.o pm-imx3.o
imx5-pm-$(CONFIG_PM) += pm-imx5.o
-obj-$(CONFIG_SOC_IMX5) += cpu-imx5.o clk-imx51-imx53.o $(imx5-pm-y)
+obj-$(CONFIG_SOC_IMX5) += cpu-imx5.o clk-imx51-imx53.o clk-cpu.o $(imx5-pm-y)
obj-$(CONFIG_COMMON_CLK) += clk-pllv1.o clk-pllv2.o clk-pllv3.o clk-gate2.o \
clk-pfd.o clk-busy.o clk.o \
diff --git a/arch/arm/mach-imx/clk-cpu.c b/arch/arm/mach-imx/clk-cpu.c
new file mode 100644
index 000000000000..aa1c345e2a19
--- /dev/null
+++ b/arch/arm/mach-imx/clk-cpu.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2014 Lucas Stach <l.stach@pengutronix.de>, Pengutronix
+ *
+ * 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.
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+
+struct clk_cpu {
+ struct clk_hw hw;
+ struct clk *div;
+ struct clk *mux;
+ struct clk *pll;
+ struct clk *step;
+};
+
+static inline struct clk_cpu *to_clk_cpu(struct clk_hw *hw)
+{
+ return container_of(hw, struct clk_cpu, hw);
+}
+
+static unsigned long clk_cpu_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_cpu *cpu = to_clk_cpu(hw);
+
+ return clk_get_rate(cpu->div);
+}
+
+static long clk_cpu_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ struct clk_cpu *cpu = to_clk_cpu(hw);
+
+ return clk_round_rate(cpu->pll, rate);
+}
+
+static int clk_cpu_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_cpu *cpu = to_clk_cpu(hw);
+ int ret;
+
+ /* switch to PLL bypass clock */
+ ret = clk_set_parent(cpu->mux, cpu->step);
+ if (ret)
+ return ret;
+
+ /* reprogram PLL */
+ ret = clk_set_rate(cpu->pll, rate);
+ if (ret) {
+ clk_set_parent(cpu->mux, cpu->pll);
+ return ret;
+ }
+ /* switch back to PLL clock */
+ clk_set_parent(cpu->mux, cpu->pll);
+
+ /* Ensure the divider is what we expect */
+ clk_set_rate(cpu->div, rate);
+
+ return 0;
+}
+
+static const struct clk_ops clk_cpu_ops = {
+ .recalc_rate = clk_cpu_recalc_rate,
+ .round_rate = clk_cpu_round_rate,
+ .set_rate = clk_cpu_set_rate,
+};
+
+struct clk *imx_clk_cpu(const char *name, const char *parent_name,
+ struct clk *div, struct clk *mux, struct clk *pll,
+ struct clk *step)
+{
+ struct clk_cpu *cpu;
+ struct clk *clk;
+ struct clk_init_data init;
+
+ cpu = kzalloc(sizeof(*cpu), GFP_KERNEL);
+ if (!cpu)
+ return ERR_PTR(-ENOMEM);
+
+ cpu->div = div;
+ cpu->mux = mux;
+ cpu->pll = pll;
+ cpu->step = step;
+
+ init.name = name;
+ init.ops = &clk_cpu_ops;
+ init.flags = 0;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ cpu->hw.init = &init;
+
+ clk = clk_register(NULL, &cpu->hw);
+ if (IS_ERR(clk))
+ kfree(cpu);
+
+ return clk;
+}
diff --git a/arch/arm/mach-imx/clk.h b/arch/arm/mach-imx/clk.h
index 4cdf8b6a74e8..5ef82e2f8fc5 100644
--- a/arch/arm/mach-imx/clk.h
+++ b/arch/arm/mach-imx/clk.h
@@ -131,4 +131,8 @@ static inline struct clk *imx_clk_fixed_factor(const char *name,
CLK_SET_RATE_PARENT, mult, div);
}
+struct clk *imx_clk_cpu(const char *name, const char *parent_name,
+ struct clk *div, struct clk *mux, struct clk *pll,
+ struct clk *step);
+
#endif