1 files changed, 262 insertions, 0 deletions
diff --git a/drivers/clk/mvebu/dove-divider.c b/drivers/clk/mvebu/dove-divider.c
new file mode 100644
index 000000000..0a90452ee
--- /dev/null
+++ b/drivers/clk/mvebu/dove-divider.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Marvell Dove PMU Core PLL divider driver
+ *
+ * Cleaned up by substantially rewriting, and converted to DT by
+ * Russell King.  Origin is not known.
+ */
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "dove-divider.h"
+
+struct dove_clk {
+	const char *name;
+	struct clk_hw hw;
+	void __iomem *base;
+	spinlock_t *lock;
+	u8 div_bit_start;
+	u8 div_bit_end;
+	u8 div_bit_load;
+	u8 div_bit_size;
+	u32 *divider_table;
+};
+
+enum {
+	DIV_CTRL0 = 0,
+	DIV_CTRL1 = 4,
+	DIV_CTRL1_N_RESET_MASK = BIT(10),
+};
+
+#define to_dove_clk(hw) container_of(hw, struct dove_clk, hw)
+
+static void dove_load_divider(void __iomem *base, u32 val, u32 mask, u32 load)
+{
+	u32 v;
+
+	v = readl_relaxed(base + DIV_CTRL1) | DIV_CTRL1_N_RESET_MASK;
+	writel_relaxed(v, base + DIV_CTRL1);
+
+	v = (readl_relaxed(base + DIV_CTRL0) & ~(mask | load)) | val;
+	writel_relaxed(v, base + DIV_CTRL0);
+	writel_relaxed(v | load, base + DIV_CTRL0);
+	ndelay(250);
+	writel_relaxed(v, base + DIV_CTRL0);
+}
+
+static unsigned int dove_get_divider(struct dove_clk *dc)
+{
+	unsigned int divider;
+	u32 val;
+
+	val = readl_relaxed(dc->base + DIV_CTRL0);
+	val >>= dc->div_bit_start;
+
+	divider = val & ~(~0 << dc->div_bit_size);
+
+	if (dc->divider_table)
+		divider = dc->divider_table[divider];
+
+	return divider;
+}
+
+static int dove_calc_divider(const struct dove_clk *dc, unsigned long rate,
+			     unsigned long parent_rate, bool set)
+{
+	unsigned int divider, max;
+
+	divider = DIV_ROUND_CLOSEST(parent_rate, rate);
+
+	if (dc->divider_table) {
+		unsigned int i;
+
+		for (i = 0; dc->divider_table[i]; i++)
+			if (divider == dc->divider_table[i]) {
+				divider = i;
+				break;
+			}
+
+		if (!dc->divider_table[i])
+			return -EINVAL;
+	} else {
+		max = 1 << dc->div_bit_size;
+
+		if (set && (divider == 0 || divider >= max))
+			return -EINVAL;
+		if (divider >= max)
+			divider = max - 1;
+		else if (divider == 0)
+			divider = 1;
+	}
+
+	return divider;
+}
+
+static unsigned long dove_recalc_rate(struct clk_hw *hw, unsigned long parent)
+{
+	struct dove_clk *dc = to_dove_clk(hw);
+	unsigned int divider = dove_get_divider(dc);
+	unsigned long rate = DIV_ROUND_CLOSEST(parent, divider);
+
+	pr_debug("%s(): %s divider=%u parent=%lu rate=%lu\n",
+		 __func__, dc->name, divider, parent, rate);
+
+	return rate;
+}
+
+static long dove_round_rate(struct clk_hw *hw, unsigned long rate,
+			    unsigned long *parent)
+{
+	struct dove_clk *dc = to_dove_clk(hw);
+	unsigned long parent_rate = *parent;
+	int divider;
+
+	divider = dove_calc_divider(dc, rate, parent_rate, false);
+	if (divider < 0)
+		return divider;
+
+	rate = DIV_ROUND_CLOSEST(parent_rate, divider);
+
+	pr_debug("%s(): %s divider=%u parent=%lu rate=%lu\n",
+		 __func__, dc->name, divider, parent_rate, rate);
+
+	return rate;
+}
+
+static int dove_set_clock(struct clk_hw *hw, unsigned long rate,
+			  unsigned long parent_rate)
+{
+	struct dove_clk *dc = to_dove_clk(hw);
+	u32 mask, load, div;
+	int divider;
+
+	divider = dove_calc_divider(dc, rate, parent_rate, true);
+	if (divider < 0)
+		return divider;
+
+	pr_debug("%s(): %s divider=%u parent=%lu rate=%lu\n",
+		 __func__, dc->name, divider, parent_rate, rate);
+
+	div = (u32)divider << dc->div_bit_start;
+	mask = ~(~0 << dc->div_bit_size) << dc->div_bit_start;
+	load = BIT(dc->div_bit_load);
+
+	spin_lock(dc->lock);
+	dove_load_divider(dc->base, div, mask, load);
+	spin_unlock(dc->lock);
+
+	return 0;
+}
+
+static const struct clk_ops dove_divider_ops = {
+	.set_rate	= dove_set_clock,
+	.round_rate	= dove_round_rate,
+	.recalc_rate	= dove_recalc_rate,
+};
+
+static struct clk *clk_register_dove_divider(struct device *dev,
+	struct dove_clk *dc, const char **parent_names, size_t num_parents,
+	void __iomem *base)
+{
+	char name[32];
+	struct clk_init_data init = {
+		.name = name,
+		.ops = &dove_divider_ops,
+		.parent_names = parent_names,
+		.num_parents = num_parents,
+	};
+
+	strscpy(name, dc->name, sizeof(name));
+
+	dc->hw.init = &init;
+	dc->base = base;
+	dc->div_bit_size = dc->div_bit_end - dc->div_bit_start + 1;
+
+	return clk_register(dev, &dc->hw);
+}
+
+static DEFINE_SPINLOCK(dove_divider_lock);
+
+static u32 axi_divider[] = {-1, 2, 1, 3, 4, 6, 5, 7, 8, 10, 9, 0};
+
+static struct dove_clk dove_hw_clocks[4] = {
+	{
+		.name = "axi",
+		.lock = &dove_divider_lock,
+		.div_bit_start = 1,
+		.div_bit_end = 6,
+		.div_bit_load = 7,
+		.divider_table = axi_divider,
+	}, {
+		.name = "gpu",
+		.lock = &dove_divider_lock,
+		.div_bit_start = 8,
+		.div_bit_end = 13,
+		.div_bit_load = 14,
+	}, {
+		.name = "vmeta",
+		.lock = &dove_divider_lock,
+		.div_bit_start = 15,
+		.div_bit_end = 20,
+		.div_bit_load = 21,
+	}, {
+		.name = "lcd",
+		.lock = &dove_divider_lock,
+		.div_bit_start = 22,
+		.div_bit_end = 27,
+		.div_bit_load = 28,
+	},
+};
+
+static const char *core_pll[] = {
+	"core-pll",
+};
+
+static int dove_divider_init(struct device *dev, void __iomem *base,
+	struct clk **clks)
+{
+	struct clk *clk;
+	int i;
+
+	/*
+	 * Create the core PLL clock.  We treat this as a fixed rate
+	 * clock as we don't know any better, and documentation is sparse.
+	 */
+	clk = clk_register_fixed_rate(dev, core_pll[0], NULL, 0, 2000000000UL);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	for (i = 0; i < ARRAY_SIZE(dove_hw_clocks); i++)
+		clks[i] = clk_register_dove_divider(dev, &dove_hw_clocks[i],
+						    core_pll,
+						    ARRAY_SIZE(core_pll), base);
+
+	return 0;
+}
+
+static struct clk *dove_divider_clocks[4];
+
+static struct clk_onecell_data dove_divider_data = {
+	.clks = dove_divider_clocks,
+	.clk_num = ARRAY_SIZE(dove_divider_clocks),
+};
+
+void __init dove_divider_clk_init(struct device_node *np)
+{
+	void __iomem *base;
+
+	base = of_iomap(np, 0);
+	if (WARN_ON(!base))
+		return;
+
+	if (WARN_ON(dove_divider_init(NULL, base, dove_divider_clocks))) {
+		iounmap(base);
+		return;
+	}
+
+	of_clk_add_provider(np, of_clk_src_onecell_get, &dove_divider_data);
+}