1 files changed, 85 insertions, 0 deletions
diff --git a/drivers/clk/clk-tango4.c b/drivers/clk/clk-tango4.c
new file mode 100644
index 000000000..34b22b793
--- /dev/null
+++ b/drivers/clk/clk-tango4.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/clk-provider.h>
+#include <linux/of_address.h>
+#include <linux/init.h>
+#include <linux/io.h>
+
+#define CLK_COUNT 4 /* cpu_clk, sys_clk, usb_clk, sdio_clk */
+static struct clk *clks[CLK_COUNT];
+static struct clk_onecell_data clk_data = { clks, CLK_COUNT };
+
+#define SYSCLK_DIV	0x20
+#define CPUCLK_DIV	0x24
+#define DIV_BYPASS	BIT(23)
+
+/*** CLKGEN_PLL ***/
+#define extract_pll_n(val)	((val >>  0) & ((1u << 7) - 1))
+#define extract_pll_k(val)	((val >> 13) & ((1u << 3) - 1))
+#define extract_pll_m(val)	((val >> 16) & ((1u << 3) - 1))
+#define extract_pll_isel(val)	((val >> 24) & ((1u << 3) - 1))
+
+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(base + idx * 8);
+	mul =  extract_pll_n(val) + 1;
+	div = (extract_pll_m(val) + 1) << extract_pll_k(val);
+	clk_register_fixed_factor(NULL, name, parent, 0, mul, div);
+	if (extract_pll_isel(val) != 1)
+		panic("%s: input not set to XTAL_IN\n", name);
+}
+
+static void __init make_cd(int idx, void __iomem *base)
+{
+	char name[8];
+	u32 val, mul, div;
+
+	sprintf(name, "cd%d", idx);
+	val = readl(base + idx * 8);
+	mul =  1 << 27;
+	div = (2 << 27) + val;
+	clk_register_fixed_factor(NULL, name, "pll2", 0, mul, div);
+	if (val > 0xf0000000)
+		panic("%s: unsupported divider %x\n", name, val);
+}
+
+static void __init tango4_clkgen_setup(struct device_node *np)
+{
+	struct clk **pp = clk_data.clks;
+	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->name);
+
+	if (readl(base + CPUCLK_DIV) & DIV_BYPASS)
+		panic("%s: unsupported cpuclk setup\n", np->name);
+
+	if (readl(base + SYSCLK_DIV) & DIV_BYPASS)
+		panic("%s: unsupported sysclk setup\n", np->name);
+
+	writel(0x100, base + CPUCLK_DIV); /* disable frequency ramping */
+
+	make_pll(0, parent, base);
+	make_pll(1, parent, base);
+	make_pll(2, parent, base);
+	make_cd(2, base + 0x80);
+	make_cd(6, base + 0x80);
+
+	pp[0] = clk_register_divider(NULL, "cpu_clk", "pll0", 0,
+			base + CPUCLK_DIV, 8, 8, CLK_DIVIDER_ONE_BASED, NULL);
+	pp[1] = clk_register_fixed_factor(NULL, "sys_clk", "pll1", 0, 1, 4);
+	pp[2] = clk_register_fixed_factor(NULL,  "usb_clk", "cd2", 0, 1, 2);
+	pp[3] = clk_register_fixed_factor(NULL, "sdio_clk", "cd6", 0, 1, 2);
+
+	if (IS_ERR(pp[0]) || IS_ERR(pp[1]) || IS_ERR(pp[2]) || IS_ERR(pp[3]))
+		panic("%s: clk registration failed\n", np->name);
+
+	if (of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data))
+		panic("%s: clk provider registration failed\n", np->name);
+}
+CLK_OF_DECLARE(tango4_clkgen, "sigma,tango4-clkgen", tango4_clkgen_setup);