clk: tango4: clkgen driver for Tango4 platforms

Provide support for Sigma Designs Tango4 clock generator.
NOTE: This driver is incompatible with Tango3 clkgen.

Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
[sboyd@codeaurora.org: Add kernel.h include for panic/sprintf]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 61 insertions, 0 deletions

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);