1 files changed, 344 insertions, 0 deletions
diff --git a/drivers/clk/axs10x/pll_clock.c b/drivers/clk/axs10x/pll_clock.c
new file mode 100644
index 000000000..500345d99
--- /dev/null
+++ b/drivers/clk/axs10x/pll_clock.c
@@ -0,0 +1,344 @@
+/*
+ * Synopsys AXS10X SDP Generic PLL clock driver
+ *
+ * Copyright (C) 2017 Synopsys
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+/* PLL registers addresses */
+#define PLL_REG_IDIV	0x0
+#define PLL_REG_FBDIV	0x4
+#define PLL_REG_ODIV	0x8
+
+/*
+ * Bit fields of the PLL IDIV/FBDIV/ODIV registers:
+ *  ________________________________________________________________________
+ * |31                15|    14    |   13   |  12  |11         6|5         0|
+ * |-------RESRVED------|-NOUPDATE-|-BYPASS-|-EDGE-|--HIGHTIME--|--LOWTIME--|
+ * |____________________|__________|________|______|____________|___________|
+ *
+ * Following macros determine the way of access to these registers
+ * They should be set up only using the macros.
+ * reg should be an u32 variable.
+ */
+
+#define PLL_REG_GET_LOW(reg)			\
+	(((reg) & (0x3F << 0)) >> 0)
+#define PLL_REG_GET_HIGH(reg)			\
+	(((reg) & (0x3F << 6)) >> 6)
+#define PLL_REG_GET_EDGE(reg)			\
+	(((reg) & (BIT(12))) ? 1 : 0)
+#define PLL_REG_GET_BYPASS(reg)			\
+	(((reg) & (BIT(13))) ? 1 : 0)
+#define PLL_REG_GET_NOUPD(reg)			\
+	(((reg) & (BIT(14))) ? 1 : 0)
+#define PLL_REG_GET_PAD(reg)			\
+	(((reg) & (0x1FFFF << 15)) >> 15)
+
+#define PLL_REG_SET_LOW(reg, value)		\
+	{ reg |= (((value) & 0x3F) << 0); }
+#define PLL_REG_SET_HIGH(reg, value)		\
+	{ reg |= (((value) & 0x3F) << 6); }
+#define PLL_REG_SET_EDGE(reg, value)		\
+	{ reg |= (((value) & 0x01) << 12); }
+#define PLL_REG_SET_BYPASS(reg, value)		\
+	{ reg |= (((value) & 0x01) << 13); }
+#define PLL_REG_SET_NOUPD(reg, value)		\
+	{ reg |= (((value) & 0x01) << 14); }
+#define PLL_REG_SET_PAD(reg, value)		\
+	{ reg |= (((value) & 0x1FFFF) << 15); }
+
+#define PLL_LOCK	BIT(0)
+#define PLL_ERROR	BIT(1)
+#define PLL_MAX_LOCK_TIME 100 /* 100 us */
+
+struct axs10x_pll_cfg {
+	u32 rate;
+	u32 idiv;
+	u32 fbdiv;
+	u32 odiv;
+};
+
+static const struct axs10x_pll_cfg arc_pll_cfg[] = {
+	{ 33333333,  1, 1,  1 },
+	{ 50000000,  1, 30, 20 },
+	{ 75000000,  2, 45, 10 },
+	{ 90000000,  2, 54, 10 },
+	{ 100000000, 1, 30, 10 },
+	{ 125000000, 2, 45, 6 },
+	{}
+};
+
+static const struct axs10x_pll_cfg pgu_pll_cfg[] = {
+	{ 25200000, 1, 84, 90 },
+	{ 50000000, 1, 100, 54 },
+	{ 74250000, 1, 44, 16 },
+	{}
+};
+
+struct axs10x_pll_clk {
+	struct clk_hw hw;
+	void __iomem *base;
+	void __iomem *lock;
+	const struct axs10x_pll_cfg *pll_cfg;
+	struct device *dev;
+};
+
+static inline void axs10x_pll_write(struct axs10x_pll_clk *clk, u32 reg,
+				    u32 val)
+{
+	iowrite32(val, clk->base + reg);
+}
+
+static inline u32 axs10x_pll_read(struct axs10x_pll_clk *clk, u32 reg)
+{
+	return ioread32(clk->base + reg);
+}
+
+static inline struct axs10x_pll_clk *to_axs10x_pll_clk(struct clk_hw *hw)
+{
+	return container_of(hw, struct axs10x_pll_clk, hw);
+}
+
+static inline u32 axs10x_div_get_value(u32 reg)
+{
+	if (PLL_REG_GET_BYPASS(reg))
+		return 1;
+
+	return PLL_REG_GET_HIGH(reg) + PLL_REG_GET_LOW(reg);
+}
+
+static inline u32 axs10x_encode_div(unsigned int id, int upd)
+{
+	u32 div = 0;
+
+	PLL_REG_SET_LOW(div, (id % 2 == 0) ? id >> 1 : (id >> 1) + 1);
+	PLL_REG_SET_HIGH(div, id >> 1);
+	PLL_REG_SET_EDGE(div, id % 2);
+	PLL_REG_SET_BYPASS(div, id == 1 ? 1 : 0);
+	PLL_REG_SET_NOUPD(div, upd == 0 ? 1 : 0);
+
+	return div;
+}
+
+static unsigned long axs10x_pll_recalc_rate(struct clk_hw *hw,
+					    unsigned long parent_rate)
+{
+	u64 rate;
+	u32 idiv, fbdiv, odiv;
+	struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
+
+	idiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_IDIV));
+	fbdiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_FBDIV));
+	odiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_ODIV));
+
+	rate = (u64)parent_rate * fbdiv;
+	do_div(rate, idiv * odiv);
+
+	return rate;
+}
+
+static long axs10x_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long *prate)
+{
+	int i;
+	long best_rate;
+	struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
+	const struct axs10x_pll_cfg *pll_cfg = clk->pll_cfg;
+
+	if (pll_cfg[0].rate == 0)
+		return -EINVAL;
+
+	best_rate = pll_cfg[0].rate;
+
+	for (i = 1; pll_cfg[i].rate != 0; i++) {
+		if (abs(rate - pll_cfg[i].rate) < abs(rate - best_rate))
+			best_rate = pll_cfg[i].rate;
+	}
+
+	return best_rate;
+}
+
+static int axs10x_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long parent_rate)
+{
+	int i;
+	struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
+	const struct axs10x_pll_cfg *pll_cfg = clk->pll_cfg;
+
+	for (i = 0; pll_cfg[i].rate != 0; i++) {
+		if (pll_cfg[i].rate == rate) {
+			axs10x_pll_write(clk, PLL_REG_IDIV,
+					 axs10x_encode_div(pll_cfg[i].idiv, 0));
+			axs10x_pll_write(clk, PLL_REG_FBDIV,
+					 axs10x_encode_div(pll_cfg[i].fbdiv, 0));
+			axs10x_pll_write(clk, PLL_REG_ODIV,
+					 axs10x_encode_div(pll_cfg[i].odiv, 1));
+
+			/*
+			 * Wait until CGU relocks and check error status.
+			 * If after timeout CGU is unlocked yet return error
+			 */
+			udelay(PLL_MAX_LOCK_TIME);
+			if (!(ioread32(clk->lock) & PLL_LOCK))
+				return -ETIMEDOUT;
+
+			if (ioread32(clk->lock) & PLL_ERROR)
+				return -EINVAL;
+
+			return 0;
+		}
+	}
+
+	dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
+			parent_rate);
+	return -EINVAL;
+}
+
+static const struct clk_ops axs10x_pll_ops = {
+	.recalc_rate = axs10x_pll_recalc_rate,
+	.round_rate = axs10x_pll_round_rate,
+	.set_rate = axs10x_pll_set_rate,
+};
+
+static int axs10x_pll_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const char *parent_name;
+	struct axs10x_pll_clk *pll_clk;
+	struct clk_init_data init = { };
+	int ret;
+
+	pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
+	if (!pll_clk)
+		return -ENOMEM;
+
+	pll_clk->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(pll_clk->base))
+		return PTR_ERR(pll_clk->base);
+
+	pll_clk->lock = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(pll_clk->lock))
+		return PTR_ERR(pll_clk->lock);
+
+	init.name = dev->of_node->name;
+	init.ops = &axs10x_pll_ops;
+	parent_name = of_clk_get_parent_name(dev->of_node, 0);
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+	pll_clk->hw.init = &init;
+	pll_clk->dev = dev;
+	pll_clk->pll_cfg = of_device_get_match_data(dev);
+
+	if (!pll_clk->pll_cfg) {
+		dev_err(dev, "No OF match data provided\n");
+		return -EINVAL;
+	}
+
+	ret = devm_clk_hw_register(dev, &pll_clk->hw);
+	if (ret) {
+		dev_err(dev, "failed to register %s clock\n", init.name);
+		return ret;
+	}
+
+	return of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get,
+			&pll_clk->hw);
+}
+
+static int axs10x_pll_clk_remove(struct platform_device *pdev)
+{
+	of_clk_del_provider(pdev->dev.of_node);
+	return 0;
+}
+
+static void __init of_axs10x_pll_clk_setup(struct device_node *node)
+{
+	const char *parent_name;
+	struct axs10x_pll_clk *pll_clk;
+	struct clk_init_data init = { };
+	int ret;
+
+	pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
+	if (!pll_clk)
+		return;
+
+	pll_clk->base = of_iomap(node, 0);
+	if (!pll_clk->base) {
+		pr_err("failed to map pll div registers\n");
+		goto err_free_pll_clk;
+	}
+
+	pll_clk->lock = of_iomap(node, 1);
+	if (!pll_clk->lock) {
+		pr_err("failed to map pll lock register\n");
+		goto err_unmap_base;
+	}
+
+	init.name = node->name;
+	init.ops = &axs10x_pll_ops;
+	parent_name = of_clk_get_parent_name(node, 0);
+	init.parent_names = &parent_name;
+	init.num_parents = parent_name ? 1 : 0;
+	pll_clk->hw.init = &init;
+	pll_clk->pll_cfg = arc_pll_cfg;
+
+	ret = clk_hw_register(NULL, &pll_clk->hw);
+	if (ret) {
+		pr_err("failed to register %pOFn clock\n", node);
+		goto err_unmap_lock;
+	}
+
+	ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &pll_clk->hw);
+	if (ret) {
+		pr_err("failed to add hw provider for %pOFn clock\n", node);
+		goto err_unregister_clk;
+	}
+
+	return;
+
+err_unregister_clk:
+	clk_hw_unregister(&pll_clk->hw);
+err_unmap_lock:
+	iounmap(pll_clk->lock);
+err_unmap_base:
+	iounmap(pll_clk->base);
+err_free_pll_clk:
+	kfree(pll_clk);
+}
+CLK_OF_DECLARE(axs10x_pll_clock, "snps,axs10x-arc-pll-clock",
+	       of_axs10x_pll_clk_setup);
+
+static const struct of_device_id axs10x_pll_clk_id[] = {
+	{ .compatible = "snps,axs10x-pgu-pll-clock", .data = &pgu_pll_cfg},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, axs10x_pll_clk_id);
+
+static struct platform_driver axs10x_pll_clk_driver = {
+	.driver = {
+		.name = "axs10x-pll-clock",
+		.of_match_table = axs10x_pll_clk_id,
+	},
+	.probe = axs10x_pll_clk_probe,
+	.remove = axs10x_pll_clk_remove,
+};
+builtin_platform_driver(axs10x_pll_clk_driver);
+
+MODULE_AUTHOR("Vlad Zakharov <vzakhar@synopsys.com>");
+MODULE_DESCRIPTION("Synopsys AXS10X SDP Generic PLL Clock Driver");
+MODULE_LICENSE("GPL v2");