1 files changed, 431 insertions, 0 deletions
diff --git a/drivers/clk/clk-hsdk-pll.c b/drivers/clk/clk-hsdk-pll.c
new file mode 100644
index 000000000..c4ee280f4
--- /dev/null
+++ b/drivers/clk/clk-hsdk-pll.c
@@ -0,0 +1,431 @@
+/*
+ * Synopsys HSDK 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/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define CGU_PLL_CTRL	0x000 /* ARC PLL control register */
+#define CGU_PLL_STATUS	0x004 /* ARC PLL status register */
+#define CGU_PLL_FMEAS	0x008 /* ARC PLL frequency measurement register */
+#define CGU_PLL_MON	0x00C /* ARC PLL monitor register */
+
+#define CGU_PLL_CTRL_ODIV_SHIFT		2
+#define CGU_PLL_CTRL_IDIV_SHIFT		4
+#define CGU_PLL_CTRL_FBDIV_SHIFT	9
+#define CGU_PLL_CTRL_BAND_SHIFT		20
+
+#define CGU_PLL_CTRL_ODIV_MASK		GENMASK(3, CGU_PLL_CTRL_ODIV_SHIFT)
+#define CGU_PLL_CTRL_IDIV_MASK		GENMASK(8, CGU_PLL_CTRL_IDIV_SHIFT)
+#define CGU_PLL_CTRL_FBDIV_MASK		GENMASK(15, CGU_PLL_CTRL_FBDIV_SHIFT)
+
+#define CGU_PLL_CTRL_PD			BIT(0)
+#define CGU_PLL_CTRL_BYPASS		BIT(1)
+
+#define CGU_PLL_STATUS_LOCK		BIT(0)
+#define CGU_PLL_STATUS_ERR		BIT(1)
+
+#define HSDK_PLL_MAX_LOCK_TIME		100 /* 100 us */
+
+#define CGU_PLL_SOURCE_MAX		1
+
+#define CORE_IF_CLK_THRESHOLD_HZ	500000000
+#define CREG_CORE_IF_CLK_DIV_1		0x0
+#define CREG_CORE_IF_CLK_DIV_2		0x1
+
+struct hsdk_pll_cfg {
+	u32 rate;
+	u32 idiv;
+	u32 fbdiv;
+	u32 odiv;
+	u32 band;
+};
+
+static const struct hsdk_pll_cfg asdt_pll_cfg[] = {
+	{ 100000000,  0, 11, 3, 0 },
+	{ 133000000,  0, 15, 3, 0 },
+	{ 200000000,  1, 47, 3, 0 },
+	{ 233000000,  1, 27, 2, 0 },
+	{ 300000000,  1, 35, 2, 0 },
+	{ 333000000,  1, 39, 2, 0 },
+	{ 400000000,  1, 47, 2, 0 },
+	{ 500000000,  0, 14, 1, 0 },
+	{ 600000000,  0, 17, 1, 0 },
+	{ 700000000,  0, 20, 1, 0 },
+	{ 800000000,  0, 23, 1, 0 },
+	{ 900000000,  1, 26, 0, 0 },
+	{ 1000000000, 1, 29, 0, 0 },
+	{ 1100000000, 1, 32, 0, 0 },
+	{ 1200000000, 1, 35, 0, 0 },
+	{ 1300000000, 1, 38, 0, 0 },
+	{ 1400000000, 1, 41, 0, 0 },
+	{ 1500000000, 1, 44, 0, 0 },
+	{ 1600000000, 1, 47, 0, 0 },
+	{}
+};
+
+static const struct hsdk_pll_cfg hdmi_pll_cfg[] = {
+	{ 297000000,  0, 21, 2, 0 },
+	{ 540000000,  0, 19, 1, 0 },
+	{ 594000000,  0, 21, 1, 0 },
+	{}
+};
+
+struct hsdk_pll_clk {
+	struct clk_hw hw;
+	void __iomem *regs;
+	void __iomem *spec_regs;
+	const struct hsdk_pll_devdata *pll_devdata;
+	struct device *dev;
+};
+
+struct hsdk_pll_devdata {
+	const struct hsdk_pll_cfg *pll_cfg;
+	int (*update_rate)(struct hsdk_pll_clk *clk, unsigned long rate,
+			   const struct hsdk_pll_cfg *cfg);
+};
+
+static int hsdk_pll_core_update_rate(struct hsdk_pll_clk *, unsigned long,
+				     const struct hsdk_pll_cfg *);
+static int hsdk_pll_comm_update_rate(struct hsdk_pll_clk *, unsigned long,
+				     const struct hsdk_pll_cfg *);
+
+static const struct hsdk_pll_devdata core_pll_devdata = {
+	.pll_cfg = asdt_pll_cfg,
+	.update_rate = hsdk_pll_core_update_rate,
+};
+
+static const struct hsdk_pll_devdata sdt_pll_devdata = {
+	.pll_cfg = asdt_pll_cfg,
+	.update_rate = hsdk_pll_comm_update_rate,
+};
+
+static const struct hsdk_pll_devdata hdmi_pll_devdata = {
+	.pll_cfg = hdmi_pll_cfg,
+	.update_rate = hsdk_pll_comm_update_rate,
+};
+
+static inline void hsdk_pll_write(struct hsdk_pll_clk *clk, u32 reg, u32 val)
+{
+	iowrite32(val, clk->regs + reg);
+}
+
+static inline u32 hsdk_pll_read(struct hsdk_pll_clk *clk, u32 reg)
+{
+	return ioread32(clk->regs + reg);
+}
+
+static inline void hsdk_pll_set_cfg(struct hsdk_pll_clk *clk,
+				    const struct hsdk_pll_cfg *cfg)
+{
+	u32 val = 0;
+
+	/* Powerdown and Bypass bits should be cleared */
+	val |= cfg->idiv << CGU_PLL_CTRL_IDIV_SHIFT;
+	val |= cfg->fbdiv << CGU_PLL_CTRL_FBDIV_SHIFT;
+	val |= cfg->odiv << CGU_PLL_CTRL_ODIV_SHIFT;
+	val |= cfg->band << CGU_PLL_CTRL_BAND_SHIFT;
+
+	dev_dbg(clk->dev, "write configuration: %#x\n", val);
+
+	hsdk_pll_write(clk, CGU_PLL_CTRL, val);
+}
+
+static inline bool hsdk_pll_is_locked(struct hsdk_pll_clk *clk)
+{
+	return !!(hsdk_pll_read(clk, CGU_PLL_STATUS) & CGU_PLL_STATUS_LOCK);
+}
+
+static inline bool hsdk_pll_is_err(struct hsdk_pll_clk *clk)
+{
+	return !!(hsdk_pll_read(clk, CGU_PLL_STATUS) & CGU_PLL_STATUS_ERR);
+}
+
+static inline struct hsdk_pll_clk *to_hsdk_pll_clk(struct clk_hw *hw)
+{
+	return container_of(hw, struct hsdk_pll_clk, hw);
+}
+
+static unsigned long hsdk_pll_recalc_rate(struct clk_hw *hw,
+					  unsigned long parent_rate)
+{
+	u32 val;
+	u64 rate;
+	u32 idiv, fbdiv, odiv;
+	struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw);
+
+	val = hsdk_pll_read(clk, CGU_PLL_CTRL);
+
+	dev_dbg(clk->dev, "current configuration: %#x\n", val);
+
+	/* Check if PLL is disabled */
+	if (val & CGU_PLL_CTRL_PD)
+		return 0;
+
+	/* Check if PLL is bypassed */
+	if (val & CGU_PLL_CTRL_BYPASS)
+		return parent_rate;
+
+	/* input divider = reg.idiv + 1 */
+	idiv = 1 + ((val & CGU_PLL_CTRL_IDIV_MASK) >> CGU_PLL_CTRL_IDIV_SHIFT);
+	/* fb divider = 2*(reg.fbdiv + 1) */
+	fbdiv = 2 * (1 + ((val & CGU_PLL_CTRL_FBDIV_MASK) >> CGU_PLL_CTRL_FBDIV_SHIFT));
+	/* output divider = 2^(reg.odiv) */
+	odiv = 1 << ((val & CGU_PLL_CTRL_ODIV_MASK) >> CGU_PLL_CTRL_ODIV_SHIFT);
+
+	rate = (u64)parent_rate * fbdiv;
+	do_div(rate, idiv * odiv);
+
+	return rate;
+}
+
+static long hsdk_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long *prate)
+{
+	int i;
+	unsigned long best_rate;
+	struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw);
+	const struct hsdk_pll_cfg *pll_cfg = clk->pll_devdata->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;
+	}
+
+	dev_dbg(clk->dev, "chosen best rate: %lu\n", best_rate);
+
+	return best_rate;
+}
+
+static int hsdk_pll_comm_update_rate(struct hsdk_pll_clk *clk,
+				     unsigned long rate,
+				     const struct hsdk_pll_cfg *cfg)
+{
+	hsdk_pll_set_cfg(clk, cfg);
+
+	/*
+	 * Wait until CGU relocks and check error status.
+	 * If after timeout CGU is unlocked yet return error.
+	 */
+	udelay(HSDK_PLL_MAX_LOCK_TIME);
+	if (!hsdk_pll_is_locked(clk))
+		return -ETIMEDOUT;
+
+	if (hsdk_pll_is_err(clk))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int hsdk_pll_core_update_rate(struct hsdk_pll_clk *clk,
+				     unsigned long rate,
+				     const struct hsdk_pll_cfg *cfg)
+{
+	/*
+	 * When core clock exceeds 500MHz, the divider for the interface
+	 * clock must be programmed to div-by-2.
+	 */
+	if (rate > CORE_IF_CLK_THRESHOLD_HZ)
+		iowrite32(CREG_CORE_IF_CLK_DIV_2, clk->spec_regs);
+
+	hsdk_pll_set_cfg(clk, cfg);
+
+	/*
+	 * Wait until CGU relocks and check error status.
+	 * If after timeout CGU is unlocked yet return error.
+	 */
+	udelay(HSDK_PLL_MAX_LOCK_TIME);
+	if (!hsdk_pll_is_locked(clk))
+		return -ETIMEDOUT;
+
+	if (hsdk_pll_is_err(clk))
+		return -EINVAL;
+
+	/*
+	 * Program divider to div-by-1 if we succesfuly set core clock below
+	 * 500MHz threshold.
+	 */
+	if (rate <= CORE_IF_CLK_THRESHOLD_HZ)
+		iowrite32(CREG_CORE_IF_CLK_DIV_1, clk->spec_regs);
+
+	return 0;
+}
+
+static int hsdk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+			     unsigned long parent_rate)
+{
+	int i;
+	struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw);
+	const struct hsdk_pll_cfg *pll_cfg = clk->pll_devdata->pll_cfg;
+
+	for (i = 0; pll_cfg[i].rate != 0; i++) {
+		if (pll_cfg[i].rate == rate) {
+			return clk->pll_devdata->update_rate(clk, rate,
+							     &pll_cfg[i]);
+		}
+	}
+
+	dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
+			parent_rate);
+
+	return -EINVAL;
+}
+
+static const struct clk_ops hsdk_pll_ops = {
+	.recalc_rate = hsdk_pll_recalc_rate,
+	.round_rate = hsdk_pll_round_rate,
+	.set_rate = hsdk_pll_set_rate,
+};
+
+static int hsdk_pll_clk_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct resource *mem;
+	const char *parent_name;
+	unsigned int num_parents;
+	struct hsdk_pll_clk *pll_clk;
+	struct clk_init_data init = { };
+	struct device *dev = &pdev->dev;
+
+	pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
+	if (!pll_clk)
+		return -ENOMEM;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pll_clk->regs = devm_ioremap_resource(dev, mem);
+	if (IS_ERR(pll_clk->regs))
+		return PTR_ERR(pll_clk->regs);
+
+	init.name = dev->of_node->name;
+	init.ops = &hsdk_pll_ops;
+	parent_name = of_clk_get_parent_name(dev->of_node, 0);
+	init.parent_names = &parent_name;
+	num_parents = of_clk_get_parent_count(dev->of_node);
+	if (num_parents == 0 || num_parents > CGU_PLL_SOURCE_MAX) {
+		dev_err(dev, "wrong clock parents number: %u\n", num_parents);
+		return -EINVAL;
+	}
+	init.num_parents = num_parents;
+
+	pll_clk->hw.init = &init;
+	pll_clk->dev = dev;
+	pll_clk->pll_devdata = of_device_get_match_data(dev);
+
+	if (!pll_clk->pll_devdata) {
+		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 hsdk_pll_clk_remove(struct platform_device *pdev)
+{
+	of_clk_del_provider(pdev->dev.of_node);
+	return 0;
+}
+
+static void __init of_hsdk_pll_clk_setup(struct device_node *node)
+{
+	int ret;
+	const char *parent_name;
+	unsigned int num_parents;
+	struct hsdk_pll_clk *pll_clk;
+	struct clk_init_data init = { };
+
+	pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
+	if (!pll_clk)
+		return;
+
+	pll_clk->regs = of_iomap(node, 0);
+	if (!pll_clk->regs) {
+		pr_err("failed to map pll registers\n");
+		goto err_free_pll_clk;
+	}
+
+	pll_clk->spec_regs = of_iomap(node, 1);
+	if (!pll_clk->spec_regs) {
+		pr_err("failed to map pll registers\n");
+		goto err_unmap_comm_regs;
+	}
+
+	init.name = node->name;
+	init.ops = &hsdk_pll_ops;
+	parent_name = of_clk_get_parent_name(node, 0);
+	init.parent_names = &parent_name;
+	num_parents = of_clk_get_parent_count(node);
+	if (num_parents > CGU_PLL_SOURCE_MAX) {
+		pr_err("too much clock parents: %u\n", num_parents);
+		goto err_unmap_spec_regs;
+	}
+	init.num_parents = num_parents;
+
+	pll_clk->hw.init = &init;
+	pll_clk->pll_devdata = &core_pll_devdata;
+
+	ret = clk_hw_register(NULL, &pll_clk->hw);
+	if (ret) {
+		pr_err("failed to register %s clock\n", node->name);
+		goto err_unmap_spec_regs;
+	}
+
+	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 %s clock\n", node->name);
+		goto err_unmap_spec_regs;
+	}
+
+	return;
+
+err_unmap_spec_regs:
+	iounmap(pll_clk->spec_regs);
+err_unmap_comm_regs:
+	iounmap(pll_clk->regs);
+err_free_pll_clk:
+	kfree(pll_clk);
+}
+
+/* Core PLL needed early for ARC cpus timers */
+CLK_OF_DECLARE(hsdk_pll_clock, "snps,hsdk-core-pll-clock",
+of_hsdk_pll_clk_setup);
+
+static const struct of_device_id hsdk_pll_clk_id[] = {
+	{ .compatible = "snps,hsdk-gp-pll-clock", .data = &sdt_pll_devdata},
+	{ .compatible = "snps,hsdk-hdmi-pll-clock", .data = &hdmi_pll_devdata},
+	{ }
+};
+
+static struct platform_driver hsdk_pll_clk_driver = {
+	.driver = {
+		.name = "hsdk-gp-pll-clock",
+		.of_match_table = hsdk_pll_clk_id,
+	},
+	.probe = hsdk_pll_clk_probe,
+	.remove = hsdk_pll_clk_remove,
+};
+builtin_platform_driver(hsdk_pll_clk_driver);