ARM: imx: add common clock support for pfd

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

3 files changed, 152 insertions, 1 deletions

diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 1b3f2aea8f48..4d6be8d33a26 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -11,7 +11,8 @@ obj-$(CONFIG_SOC_IMX35) += mm-imx3.o cpu-imx35.o clock-imx35.o ehci-imx35.o pm-i
 
 obj-$(CONFIG_SOC_IMX5) += cpu-imx5.o mm-imx5.o clock-mx51-mx53.o ehci-imx5.o pm-imx5.o cpu_op-mx51.o
 
-obj-$(CONFIG_COMMON_CLK) += clk-pllv1.o clk-pllv2.o clk-pllv3.o clk-gate2.o
+obj-$(CONFIG_COMMON_CLK) += clk-pllv1.o clk-pllv2.o clk-pllv3.o clk-gate2.o \
+                            clk-pfd.o
 
 # Support for CMOS sensor interface
 obj-$(CONFIG_MX1_VIDEO) += mx1-camera-fiq.o mx1-camera-fiq-ksym.o
diff --git a/arch/arm/mach-imx/clk-pfd.c b/arch/arm/mach-imx/clk-pfd.c
new file mode 100644
index 000000000000..e2ed4160f329
--- /dev/null
+++ b/arch/arm/mach-imx/clk-pfd.c
@@ -0,0 +1,147 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2012 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * 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/io.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include "clk.h"
+
+/**
+ * struct clk_pfd - IMX PFD clock
+ * @clk_hw:     clock source
+ * @reg:        PFD register address
+ * @idx:        the index of PFD encoded in the register
+ *
+ * PFD clock found on i.MX6 series.  Each register for PFD has 4 clk_pfd
+ * data encoded, and member idx is used to specify the one.  And each
+ * register has SET, CLR and TOG registers at offset 0x4 0x8 and 0xc.
+ */
+struct clk_pfd {
+        struct clk_hw   hw;
+        void __iomem    *reg;
+        u8              idx;
+};
+
+#define to_clk_pfd(_hw) container_of(_hw, struct clk_pfd, hw)
+
+#define SET     0x4
+#define CLR     0x8
+#define OTG     0xc
+
+static int clk_pfd_enable(struct clk_hw *hw)
+{
+        struct clk_pfd *pfd = to_clk_pfd(hw);
+
+        writel_relaxed(1 << ((pfd->idx + 1) * 8 - 1), pfd->reg + CLR);
+
+        return 0;
+}
+
+static void clk_pfd_disable(struct clk_hw *hw)
+{
+        struct clk_pfd *pfd = to_clk_pfd(hw);
+
+        writel_relaxed(1 << ((pfd->idx + 1) * 8 - 1), pfd->reg + SET);
+}
+
+static unsigned long clk_pfd_recalc_rate(struct clk_hw *hw,
+                                         unsigned long parent_rate)
+{
+        struct clk_pfd *pfd = to_clk_pfd(hw);
+        u64 tmp = parent_rate;
+        u8 frac = (readl_relaxed(pfd->reg) >> (pfd->idx * 8)) & 0x3f;
+
+        tmp *= 18;
+        do_div(tmp, frac);
+
+        return tmp;
+}
+
+static long clk_pfd_round_rate(struct clk_hw *hw, unsigned long rate,
+                               unsigned long *prate)
+{
+        u64 tmp = *prate;
+        u8 frac;
+
+        tmp = tmp * 18 + rate / 2;
+        do_div(tmp, rate);
+        frac = tmp;
+        if (frac < 12)
+                frac = 12;
+        else if (frac > 35)
+                frac = 35;
+        tmp = *prate;
+        tmp *= 18;
+        do_div(tmp, frac);
+
+        return tmp;
+}
+
+static int clk_pfd_set_rate(struct clk_hw *hw, unsigned long rate,
+                unsigned long parent_rate)
+{
+        struct clk_pfd *pfd = to_clk_pfd(hw);
+        u64 tmp = parent_rate;
+        u8 frac;
+
+        tmp = tmp * 18 + rate / 2;
+        do_div(tmp, rate);
+        frac = tmp;
+        if (frac < 12)
+                frac = 12;
+        else if (frac > 35)
+                frac = 35;
+
+        writel_relaxed(0x3f << (pfd->idx * 8), pfd->reg + CLR);
+        writel_relaxed(frac << (pfd->idx * 8), pfd->reg + SET);
+
+        return 0;
+}
+
+static const struct clk_ops clk_pfd_ops = {
+        .enable         = clk_pfd_enable,
+        .disable        = clk_pfd_disable,
+        .recalc_rate    = clk_pfd_recalc_rate,
+        .round_rate     = clk_pfd_round_rate,
+        .set_rate       = clk_pfd_set_rate,
+};
+
+struct clk *imx_clk_pfd(const char *name, const char *parent_name,
+                        void __iomem *reg, u8 idx)
+{
+        struct clk_pfd *pfd;
+        struct clk *clk;
+        struct clk_init_data init;
+
+        pfd = kzalloc(sizeof(*pfd), GFP_KERNEL);
+        if (!pfd)
+                return ERR_PTR(-ENOMEM);
+
+        pfd->reg = reg;
+        pfd->idx = idx;
+
+        init.name = name;
+        init.ops = &clk_pfd_ops;
+        init.flags = 0;
+        init.parent_names = &parent_name;
+        init.num_parents = 1;
+
+        pfd->hw.init = &init;
+
+        clk = clk_register(NULL, &pfd->hw);
+        if (IS_ERR(clk))
+                kfree(pfd);
+
+        return clk;
+}
diff --git a/arch/arm/mach-imx/clk.h b/arch/arm/mach-imx/clk.h
index 5f6e435da4ae..52970996f39a 100644
--- a/arch/arm/mach-imx/clk.h
+++ b/arch/arm/mach-imx/clk.h
@@ -36,6 +36,9 @@ static inline struct clk *imx_clk_gate2(const char *name, const char *parent,
                         shift, 0, &imx_ccm_lock);
 }
 
+struct clk *imx_clk_pfd(const char *name, const char *parent_name,
+                void __iomem *reg, u8 idx);
+
 static inline struct clk *imx_clk_fixed(const char *name, int rate)
 {
         return clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);