3 files changed, 85 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/clock/tango4-clock.txt b/Documentation/devicetree/bindings/clock/tango4-clock.txt
new file mode 100644
index 000000000000..19c580a7bda2
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/tango4-clock.txt
@@ -0,0 +1,23 @@
+* Sigma Designs Tango4 Clock Generator
+
+The Tango4 clock generator outputs cpu_clk and sys_clk (the latter is used
+for RAM and various peripheral devices). The clock binding described here
+is applicable to all Tango4 SoCs.
+
+Required Properties:
+
+- compatible: should be "sigma,tango4-clkgen".
+- reg: physical base address of the device and length of memory mapped region.
+- clocks: phandle of the input clock (crystal oscillator).
+- clock-output-names: should be "cpuclk" and "sysclk".
+- #clock-cells: should be set to 1.
+
+Example:
+
+        clkgen: clkgen@10000 {
+                compatible = "sigma,tango4-clkgen";
+                reg = <0x10000 0x40>;
+                clocks = <&xtal>;
+                clock-output-names = "cpuclk", "sysclk";
+                #clock-cells = <1>;
+        };
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 820714c72d36..f4165bb9a270 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -42,6 +42,7 @@ obj-$(CONFIG_COMMON_CLK_SI514)		+= clk-si514.o
 obj-$(CONFIG_COMMON_CLK_SI570)          += clk-si570.o
 obj-$(CONFIG_COMMON_CLK_CDCE925)        += clk-cdce925.o
 obj-$(CONFIG_ARCH_STM32)                += clk-stm32f4.o
+obj-$(CONFIG_ARCH_TANGOX)               += clk-tango4.o
 obj-$(CONFIG_CLK_TWL6040)               += clk-twl6040.o
 obj-$(CONFIG_ARCH_U300)                 += clk-u300.o
 obj-$(CONFIG_ARCH_VT8500)               += clk-vt8500.o
diff --git a/drivers/clk/clk-tango4.c b/drivers/clk/clk-tango4.c
new file mode 100644
index 000000000000..004ab7dfcfe3
--- /dev/null
+++ b/drivers/clk/clk-tango4.c
@@ -0,0 +1,61 @@
+#include <linux/kernel.h>
+#include <linux/clk-provider.h>
+#include <linux/of_address.h>
+#include <linux/init.h>
+#include <linux/io.h>
+
+static struct clk *out[2];
+static struct clk_onecell_data clk_data = { out, 2 };
+
+#define SYSCLK_CTRL     0x20
+#define CPUCLK_CTRL     0x24
+#define LEGACY_DIV      0x3c
+
+#define PLL_N(val)      (((val) >>  0) & 0x7f)
+#define PLL_K(val)      (((val) >> 13) & 0x7)
+#define PLL_M(val)      (((val) >> 16) & 0x7)
+#define DIV_INDEX(val)  (((val) >>  8) & 0xf)
+
+static void __init make_pll(int idx, const char *parent, void __iomem *base)
+{
+        char name[8];
+        u32 val, mul, div;
+
+        sprintf(name, "pll%d", idx);
+        val = readl_relaxed(base + idx*8);
+        mul =  PLL_N(val) + 1;
+        div = (PLL_M(val) + 1) << PLL_K(val);
+        clk_register_fixed_factor(NULL, name, parent, 0, mul, div);
+}
+
+static int __init get_div(void __iomem *base)
+{
+        u8 sysclk_tab[16] = { 2, 4, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4 };
+        int idx = DIV_INDEX(readl_relaxed(base + LEGACY_DIV));
+
+        return sysclk_tab[idx];
+}
+
+static void __init tango4_clkgen_setup(struct device_node *np)
+{
+        int div, ret;
+        void __iomem *base = of_iomap(np, 0);
+        const char *parent = of_clk_get_parent_name(np, 0);
+
+        if (!base)
+                panic("%s: invalid address\n", np->full_name);
+
+        make_pll(0, parent, base);
+        make_pll(1, parent, base);
+
+        out[0] = clk_register_divider(NULL, "cpuclk", "pll0", 0,
+                        base + CPUCLK_CTRL, 8, 8, CLK_DIVIDER_ONE_BASED, NULL);
+
+        div = readl_relaxed(base + SYSCLK_CTRL) & BIT(23) ? get_div(base) : 4;
+        out[1] = clk_register_fixed_factor(NULL, "sysclk", "pll1", 0, 1, div);
+
+        ret = of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
+        if (IS_ERR(out[0]) || IS_ERR(out[1]) || ret < 0)
+                panic("%s: clk registration failed\n", np->full_name);
+}
+CLK_OF_DECLARE(tango4_clkgen, "sigma,tango4-clkgen", tango4_clkgen_setup);