1 files changed, 626 insertions, 0 deletions
diff --git a/drivers/clk/sifive/sifive-prci.c b/drivers/clk/sifive/sifive-prci.c
new file mode 100644
index 0000000000..af81eb835b
--- /dev/null
+++ b/drivers/clk/sifive/sifive-prci.c
@@ -0,0 +1,626 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 SiFive, Inc.
+ * Copyright (C) 2020 Zong Li
+ */
+
+#include <linux/clkdev.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include "sifive-prci.h"
+#include "fu540-prci.h"
+#include "fu740-prci.h"
+
+/*
+ * Private functions
+ */
+
+/**
+ * __prci_readl() - read from a PRCI register
+ * @pd: PRCI context
+ * @offs: register offset to read from (in bytes, from PRCI base address)
+ *
+ * Read the register located at offset @offs from the base virtual
+ * address of the PRCI register target described by @pd, and return
+ * the value to the caller.
+ *
+ * Context: Any context.
+ *
+ * Return: the contents of the register described by @pd and @offs.
+ */
+static u32 __prci_readl(struct __prci_data *pd, u32 offs)
+{
+	return readl_relaxed(pd->va + offs);
+}
+
+static void __prci_writel(u32 v, u32 offs, struct __prci_data *pd)
+{
+	writel_relaxed(v, pd->va + offs);
+}
+
+/* WRPLL-related private functions */
+
+/**
+ * __prci_wrpll_unpack() - unpack WRPLL configuration registers into parameters
+ * @c: ptr to a struct wrpll_cfg record to write config into
+ * @r: value read from the PRCI PLL configuration register
+ *
+ * Given a value @r read from an FU740 PRCI PLL configuration register,
+ * split it into fields and populate it into the WRPLL configuration record
+ * pointed to by @c.
+ *
+ * The COREPLLCFG0 macros are used below, but the other *PLLCFG0 macros
+ * have the same register layout.
+ *
+ * Context: Any context.
+ */
+static void __prci_wrpll_unpack(struct wrpll_cfg *c, u32 r)
+{
+	u32 v;
+
+	v = r & PRCI_COREPLLCFG0_DIVR_MASK;
+	v >>= PRCI_COREPLLCFG0_DIVR_SHIFT;
+	c->divr = v;
+
+	v = r & PRCI_COREPLLCFG0_DIVF_MASK;
+	v >>= PRCI_COREPLLCFG0_DIVF_SHIFT;
+	c->divf = v;
+
+	v = r & PRCI_COREPLLCFG0_DIVQ_MASK;
+	v >>= PRCI_COREPLLCFG0_DIVQ_SHIFT;
+	c->divq = v;
+
+	v = r & PRCI_COREPLLCFG0_RANGE_MASK;
+	v >>= PRCI_COREPLLCFG0_RANGE_SHIFT;
+	c->range = v;
+
+	c->flags &=
+	    (WRPLL_FLAGS_INT_FEEDBACK_MASK | WRPLL_FLAGS_EXT_FEEDBACK_MASK);
+
+	/* external feedback mode not supported */
+	c->flags |= WRPLL_FLAGS_INT_FEEDBACK_MASK;
+}
+
+/**
+ * __prci_wrpll_pack() - pack PLL configuration parameters into a register value
+ * @c: pointer to a struct wrpll_cfg record containing the PLL's cfg
+ *
+ * Using a set of WRPLL configuration values pointed to by @c,
+ * assemble a PRCI PLL configuration register value, and return it to
+ * the caller.
+ *
+ * Context: Any context.  Caller must ensure that the contents of the
+ *          record pointed to by @c do not change during the execution
+ *          of this function.
+ *
+ * Returns: a value suitable for writing into a PRCI PLL configuration
+ *          register
+ */
+static u32 __prci_wrpll_pack(const struct wrpll_cfg *c)
+{
+	u32 r = 0;
+
+	r |= c->divr << PRCI_COREPLLCFG0_DIVR_SHIFT;
+	r |= c->divf << PRCI_COREPLLCFG0_DIVF_SHIFT;
+	r |= c->divq << PRCI_COREPLLCFG0_DIVQ_SHIFT;
+	r |= c->range << PRCI_COREPLLCFG0_RANGE_SHIFT;
+
+	/* external feedback mode not supported */
+	r |= PRCI_COREPLLCFG0_FSE_MASK;
+
+	return r;
+}
+
+/**
+ * __prci_wrpll_read_cfg0() - read the WRPLL configuration from the PRCI
+ * @pd: PRCI context
+ * @pwd: PRCI WRPLL metadata
+ *
+ * Read the current configuration of the PLL identified by @pwd from
+ * the PRCI identified by @pd, and store it into the local configuration
+ * cache in @pwd.
+ *
+ * Context: Any context.  Caller must prevent the records pointed to by
+ *          @pd and @pwd from changing during execution.
+ */
+static void __prci_wrpll_read_cfg0(struct __prci_data *pd,
+				   struct __prci_wrpll_data *pwd)
+{
+	__prci_wrpll_unpack(&pwd->c, __prci_readl(pd, pwd->cfg0_offs));
+}
+
+/**
+ * __prci_wrpll_write_cfg0() - write WRPLL configuration into the PRCI
+ * @pd: PRCI context
+ * @pwd: PRCI WRPLL metadata
+ * @c: WRPLL configuration record to write
+ *
+ * Write the WRPLL configuration described by @c into the WRPLL
+ * configuration register identified by @pwd in the PRCI instance
+ * described by @c.  Make a cached copy of the WRPLL's current
+ * configuration so it can be used by other code.
+ *
+ * Context: Any context.  Caller must prevent the records pointed to by
+ *          @pd and @pwd from changing during execution.
+ */
+static void __prci_wrpll_write_cfg0(struct __prci_data *pd,
+				    struct __prci_wrpll_data *pwd,
+				    struct wrpll_cfg *c)
+{
+	__prci_writel(__prci_wrpll_pack(c), pwd->cfg0_offs, pd);
+
+	memcpy(&pwd->c, c, sizeof(*c));
+}
+
+/**
+ * __prci_wrpll_write_cfg1() - write Clock enable/disable configuration
+ * into the PRCI
+ * @pd: PRCI context
+ * @pwd: PRCI WRPLL metadata
+ * @enable: Clock enable or disable value
+ */
+static void __prci_wrpll_write_cfg1(struct __prci_data *pd,
+				    struct __prci_wrpll_data *pwd,
+				    u32 enable)
+{
+	__prci_writel(enable, pwd->cfg1_offs, pd);
+}
+
+/*
+ * Linux clock framework integration
+ *
+ * See the Linux clock framework documentation for more information on
+ * these functions.
+ */
+
+unsigned long sifive_prci_wrpll_recalc_rate(struct clk_hw *hw,
+					    unsigned long parent_rate)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_wrpll_data *pwd = pc->pwd;
+
+	return wrpll_calc_output_rate(&pwd->c, parent_rate);
+}
+
+long sifive_prci_wrpll_round_rate(struct clk_hw *hw,
+				  unsigned long rate,
+				  unsigned long *parent_rate)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_wrpll_data *pwd = pc->pwd;
+	struct wrpll_cfg c;
+
+	memcpy(&c, &pwd->c, sizeof(c));
+
+	wrpll_configure_for_rate(&c, rate, *parent_rate);
+
+	return wrpll_calc_output_rate(&c, *parent_rate);
+}
+
+int sifive_prci_wrpll_set_rate(struct clk_hw *hw,
+			       unsigned long rate, unsigned long parent_rate)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_wrpll_data *pwd = pc->pwd;
+	struct __prci_data *pd = pc->pd;
+	int r;
+
+	r = wrpll_configure_for_rate(&pwd->c, rate, parent_rate);
+	if (r)
+		return r;
+
+	if (pwd->enable_bypass)
+		pwd->enable_bypass(pd);
+
+	__prci_wrpll_write_cfg0(pd, pwd, &pwd->c);
+
+	udelay(wrpll_calc_max_lock_us(&pwd->c));
+
+	return 0;
+}
+
+int sifive_clk_is_enabled(struct clk_hw *hw)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_wrpll_data *pwd = pc->pwd;
+	struct __prci_data *pd = pc->pd;
+	u32 r;
+
+	r = __prci_readl(pd, pwd->cfg1_offs);
+
+	if (r & PRCI_COREPLLCFG1_CKE_MASK)
+		return 1;
+	else
+		return 0;
+}
+
+int sifive_prci_clock_enable(struct clk_hw *hw)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_wrpll_data *pwd = pc->pwd;
+	struct __prci_data *pd = pc->pd;
+
+	if (sifive_clk_is_enabled(hw))
+		return 0;
+
+	__prci_wrpll_write_cfg1(pd, pwd, PRCI_COREPLLCFG1_CKE_MASK);
+
+	if (pwd->disable_bypass)
+		pwd->disable_bypass(pd);
+
+	return 0;
+}
+
+void sifive_prci_clock_disable(struct clk_hw *hw)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_wrpll_data *pwd = pc->pwd;
+	struct __prci_data *pd = pc->pd;
+	u32 r;
+
+	if (pwd->enable_bypass)
+		pwd->enable_bypass(pd);
+
+	r = __prci_readl(pd, pwd->cfg1_offs);
+	r &= ~PRCI_COREPLLCFG1_CKE_MASK;
+
+	__prci_wrpll_write_cfg1(pd, pwd, r);
+}
+
+/* TLCLKSEL clock integration */
+
+unsigned long sifive_prci_tlclksel_recalc_rate(struct clk_hw *hw,
+					       unsigned long parent_rate)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_data *pd = pc->pd;
+	u32 v;
+	u8 div;
+
+	v = __prci_readl(pd, PRCI_CLKMUXSTATUSREG_OFFSET);
+	v &= PRCI_CLKMUXSTATUSREG_TLCLKSEL_STATUS_MASK;
+	div = v ? 1 : 2;
+
+	return div_u64(parent_rate, div);
+}
+
+/* HFPCLK clock integration */
+
+unsigned long sifive_prci_hfpclkplldiv_recalc_rate(struct clk_hw *hw,
+						   unsigned long parent_rate)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_data *pd = pc->pd;
+	u32 div = __prci_readl(pd, PRCI_HFPCLKPLLDIV_OFFSET);
+
+	return div_u64(parent_rate, div + 2);
+}
+
+/*
+ * Core clock mux control
+ */
+
+/**
+ * sifive_prci_coreclksel_use_hfclk() - switch the CORECLK mux to output HFCLK
+ * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg
+ *
+ * Switch the CORECLK mux to the HFCLK input source; return once complete.
+ *
+ * Context: Any context.  Caller must prevent concurrent changes to the
+ *          PRCI_CORECLKSEL_OFFSET register.
+ */
+void sifive_prci_coreclksel_use_hfclk(struct __prci_data *pd)
+{
+	u32 r;
+
+	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);
+	r |= PRCI_CORECLKSEL_CORECLKSEL_MASK;
+	__prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd);
+
+	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);	/* barrier */
+}
+
+/**
+ * sifive_prci_coreclksel_use_corepll() - switch the CORECLK mux to output
+ * COREPLL
+ * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg
+ *
+ * Switch the CORECLK mux to the COREPLL output clock; return once complete.
+ *
+ * Context: Any context.  Caller must prevent concurrent changes to the
+ *          PRCI_CORECLKSEL_OFFSET register.
+ */
+void sifive_prci_coreclksel_use_corepll(struct __prci_data *pd)
+{
+	u32 r;
+
+	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);
+	r &= ~PRCI_CORECLKSEL_CORECLKSEL_MASK;
+	__prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd);
+
+	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);	/* barrier */
+}
+
+/**
+ * sifive_prci_coreclksel_use_final_corepll() - switch the CORECLK mux to output
+ * FINAL_COREPLL
+ * @pd: struct __prci_data * for the PRCI containing the CORECLK mux reg
+ *
+ * Switch the CORECLK mux to the final COREPLL output clock; return once
+ * complete.
+ *
+ * Context: Any context.  Caller must prevent concurrent changes to the
+ *          PRCI_CORECLKSEL_OFFSET register.
+ */
+void sifive_prci_coreclksel_use_final_corepll(struct __prci_data *pd)
+{
+	u32 r;
+
+	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);
+	r &= ~PRCI_CORECLKSEL_CORECLKSEL_MASK;
+	__prci_writel(r, PRCI_CORECLKSEL_OFFSET, pd);
+
+	r = __prci_readl(pd, PRCI_CORECLKSEL_OFFSET);	/* barrier */
+}
+
+/**
+ * sifive_prci_corepllsel_use_dvfscorepll() - switch the COREPLL mux to
+ * output DVFS_COREPLL
+ * @pd: struct __prci_data * for the PRCI containing the COREPLL mux reg
+ *
+ * Switch the COREPLL mux to the DVFSCOREPLL output clock; return once complete.
+ *
+ * Context: Any context.  Caller must prevent concurrent changes to the
+ *          PRCI_COREPLLSEL_OFFSET register.
+ */
+void sifive_prci_corepllsel_use_dvfscorepll(struct __prci_data *pd)
+{
+	u32 r;
+
+	r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);
+	r |= PRCI_COREPLLSEL_COREPLLSEL_MASK;
+	__prci_writel(r, PRCI_COREPLLSEL_OFFSET, pd);
+
+	r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);	/* barrier */
+}
+
+/**
+ * sifive_prci_corepllsel_use_corepll() - switch the COREPLL mux to
+ * output COREPLL
+ * @pd: struct __prci_data * for the PRCI containing the COREPLL mux reg
+ *
+ * Switch the COREPLL mux to the COREPLL output clock; return once complete.
+ *
+ * Context: Any context.  Caller must prevent concurrent changes to the
+ *          PRCI_COREPLLSEL_OFFSET register.
+ */
+void sifive_prci_corepllsel_use_corepll(struct __prci_data *pd)
+{
+	u32 r;
+
+	r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);
+	r &= ~PRCI_COREPLLSEL_COREPLLSEL_MASK;
+	__prci_writel(r, PRCI_COREPLLSEL_OFFSET, pd);
+
+	r = __prci_readl(pd, PRCI_COREPLLSEL_OFFSET);	/* barrier */
+}
+
+/**
+ * sifive_prci_hfpclkpllsel_use_hfclk() - switch the HFPCLKPLL mux to
+ * output HFCLK
+ * @pd: struct __prci_data * for the PRCI containing the HFPCLKPLL mux reg
+ *
+ * Switch the HFPCLKPLL mux to the HFCLK input source; return once complete.
+ *
+ * Context: Any context.  Caller must prevent concurrent changes to the
+ *          PRCI_HFPCLKPLLSEL_OFFSET register.
+ */
+void sifive_prci_hfpclkpllsel_use_hfclk(struct __prci_data *pd)
+{
+	u32 r;
+
+	r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET);
+	r |= PRCI_HFPCLKPLLSEL_HFPCLKPLLSEL_MASK;
+	__prci_writel(r, PRCI_HFPCLKPLLSEL_OFFSET, pd);
+
+	r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET);	/* barrier */
+}
+
+/**
+ * sifive_prci_hfpclkpllsel_use_hfpclkpll() - switch the HFPCLKPLL mux to
+ * output HFPCLKPLL
+ * @pd: struct __prci_data * for the PRCI containing the HFPCLKPLL mux reg
+ *
+ * Switch the HFPCLKPLL mux to the HFPCLKPLL output clock; return once complete.
+ *
+ * Context: Any context.  Caller must prevent concurrent changes to the
+ *          PRCI_HFPCLKPLLSEL_OFFSET register.
+ */
+void sifive_prci_hfpclkpllsel_use_hfpclkpll(struct __prci_data *pd)
+{
+	u32 r;
+
+	r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET);
+	r &= ~PRCI_HFPCLKPLLSEL_HFPCLKPLLSEL_MASK;
+	__prci_writel(r, PRCI_HFPCLKPLLSEL_OFFSET, pd);
+
+	r = __prci_readl(pd, PRCI_HFPCLKPLLSEL_OFFSET);	/* barrier */
+}
+
+/* PCIE AUX clock APIs for enable, disable. */
+int sifive_prci_pcie_aux_clock_is_enabled(struct clk_hw *hw)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_data *pd = pc->pd;
+	u32 r;
+
+	r = __prci_readl(pd, PRCI_PCIE_AUX_OFFSET);
+
+	if (r & PRCI_PCIE_AUX_EN_MASK)
+		return 1;
+	else
+		return 0;
+}
+
+int sifive_prci_pcie_aux_clock_enable(struct clk_hw *hw)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_data *pd = pc->pd;
+	u32 r __maybe_unused;
+
+	if (sifive_prci_pcie_aux_clock_is_enabled(hw))
+		return 0;
+
+	__prci_writel(1, PRCI_PCIE_AUX_OFFSET, pd);
+	r = __prci_readl(pd, PRCI_PCIE_AUX_OFFSET);	/* barrier */
+
+	return 0;
+}
+
+void sifive_prci_pcie_aux_clock_disable(struct clk_hw *hw)
+{
+	struct __prci_clock *pc = clk_hw_to_prci_clock(hw);
+	struct __prci_data *pd = pc->pd;
+	u32 r __maybe_unused;
+
+	__prci_writel(0, PRCI_PCIE_AUX_OFFSET, pd);
+	r = __prci_readl(pd, PRCI_PCIE_AUX_OFFSET);	/* barrier */
+
+}
+
+/**
+ * __prci_register_clocks() - register clock controls in the PRCI
+ * @dev: Linux struct device
+ * @pd: The pointer for PRCI per-device instance data
+ * @desc: The pointer for the information of clocks of each SoCs
+ *
+ * Register the list of clock controls described in __prci_init_clocks[] with
+ * the Linux clock framework.
+ *
+ * Return: 0 upon success or a negative error code upon failure.
+ */
+static int __prci_register_clocks(struct device *dev, struct __prci_data *pd,
+				  const struct prci_clk_desc *desc)
+{
+	struct clk_init_data init = { };
+	struct __prci_clock *pic;
+	int parent_count, i, r;
+
+	parent_count = of_clk_get_parent_count(dev->of_node);
+	if (parent_count != EXPECTED_CLK_PARENT_COUNT) {
+		dev_err(dev, "expected only two parent clocks, found %d\n",
+			parent_count);
+		return -EINVAL;
+	}
+
+	/* Register PLLs */
+	for (i = 0; i < desc->num_clks; ++i) {
+		pic = &(desc->clks[i]);
+
+		init.name = pic->name;
+		init.parent_names = &pic->parent_name;
+		init.num_parents = 1;
+		init.ops = pic->ops;
+		pic->hw.init = &init;
+
+		pic->pd = pd;
+
+		if (pic->pwd)
+			__prci_wrpll_read_cfg0(pd, pic->pwd);
+
+		r = devm_clk_hw_register(dev, &pic->hw);
+		if (r) {
+			dev_warn(dev, "Failed to register clock %s: %d\n",
+				 init.name, r);
+			return r;
+		}
+
+		r = clk_hw_register_clkdev(&pic->hw, pic->name, dev_name(dev));
+		if (r) {
+			dev_warn(dev, "Failed to register clkdev for %s: %d\n",
+				 init.name, r);
+			return r;
+		}
+
+		pd->hw_clks.hws[i] = &pic->hw;
+	}
+
+	pd->hw_clks.num = i;
+
+	r = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+					&pd->hw_clks);
+	if (r) {
+		dev_err(dev, "could not add hw_provider: %d\n", r);
+		return r;
+	}
+
+	return 0;
+}
+
+/**
+ * sifive_prci_probe() - initialize prci data and check parent count
+ * @pdev: platform device pointer for the prci
+ *
+ * Return: 0 upon success or a negative error code upon failure.
+ */
+static int sifive_prci_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct __prci_data *pd;
+	const struct prci_clk_desc *desc;
+	int r;
+
+	desc = of_device_get_match_data(&pdev->dev);
+
+	pd = devm_kzalloc(dev, struct_size(pd, hw_clks.hws, desc->num_clks), GFP_KERNEL);
+	if (!pd)
+		return -ENOMEM;
+
+	pd->va = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(pd->va))
+		return PTR_ERR(pd->va);
+
+	pd->reset.rcdev.owner = THIS_MODULE;
+	pd->reset.rcdev.nr_resets = PRCI_RST_NR;
+	pd->reset.rcdev.ops = &reset_simple_ops;
+	pd->reset.rcdev.of_node = pdev->dev.of_node;
+	pd->reset.active_low = true;
+	pd->reset.membase = pd->va + PRCI_DEVICESRESETREG_OFFSET;
+	spin_lock_init(&pd->reset.lock);
+
+	r = devm_reset_controller_register(&pdev->dev, &pd->reset.rcdev);
+	if (r) {
+		dev_err(dev, "could not register reset controller: %d\n", r);
+		return r;
+	}
+	r = __prci_register_clocks(dev, pd, desc);
+	if (r) {
+		dev_err(dev, "could not register clocks: %d\n", r);
+		return r;
+	}
+
+	dev_dbg(dev, "SiFive PRCI probed\n");
+
+	return 0;
+}
+
+static const struct of_device_id sifive_prci_of_match[] = {
+	{.compatible = "sifive,fu540-c000-prci", .data = &prci_clk_fu540},
+	{.compatible = "sifive,fu740-c000-prci", .data = &prci_clk_fu740},
+	{}
+};
+
+static struct platform_driver sifive_prci_driver = {
+	.driver = {
+		.name = "sifive-clk-prci",
+		.of_match_table = sifive_prci_of_match,
+	},
+	.probe = sifive_prci_probe,
+};
+
+static int __init sifive_prci_init(void)
+{
+	return platform_driver_register(&sifive_prci_driver);
+}
+core_initcall(sifive_prci_init);