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authorArnd Bergmann <arnd@arndb.de>2013-06-20 15:40:16 +0200
committerArnd Bergmann <arnd@arndb.de>2013-06-20 16:13:10 +0200
commit15f4b11b0fa91cf81738215483b2bb2c0b911285 (patch)
treec2f30b1b5941f35b0884f02d485a0d04d984f3a0 /drivers/clk
parentdc61cd9ecb918f593972962b97cf6079ab9d1daf (diff)
parentc641d4dfef6d462c6d66a6fb57700086cd2f0106 (diff)
downloadlinux-15f4b11b0fa91cf81738215483b2bb2c0b911285.tar.gz
Merge tag 'nomadik-dt-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-nomadik into next/dt
From Linus Walleij:

Nomadik DT and clock work:
- Lee Jones' pinctrl compat ontology patches
- A real clock driver for the Nomadik, 100% DT-based
- Device tree changes for the Nomadik clocks

* tag 'nomadik-dt-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-nomadik:
  ARM: nomadik: add the new clocks to the device tree
  clk: nomadik: implement the Nomadik clocks properly
  pinctrl/nomadik: Standardise Pinctrl compat string for Nomadik based platforms
  ARM: nomadik: Standardise Nomadik STN8815 based Pinctrl compat string in the DTS

Conflicts:
	arch/arm/boot/dts/ste-nomadik-s8815.dts

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/clk-nomadik.c551
1 files changed, 548 insertions, 3 deletions
diff --git a/drivers/clk/clk-nomadik.c b/drivers/clk/clk-nomadik.c
index 4a1ab27ee87f..6d819a37f647 100644
--- a/drivers/clk/clk-nomadik.c
+++ b/drivers/clk/clk-nomadik.c
@@ -1,21 +1,566 @@
+/*
+ * Nomadik clock implementation
+ * Copyright (C) 2013 ST-Ericsson AB
+ * License terms: GNU General Public License (GPL) version 2
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ */
+
+#define pr_fmt(fmt) "Nomadik SRC clocks: " fmt
+
+#include <linux/bitops.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/clk-provider.h>
 #include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/reboot.h>
 
 /*
  * The Nomadik clock tree is described in the STN8815A12 DB V4.2
  * reference manual for the chip, page 94 ff.
+ * Clock IDs are in the STn8815 Reference Manual table 3, page 27.
+ */
+
+#define SRC_CR			0x00U
+#define SRC_XTALCR		0x0CU
+#define SRC_XTALCR_XTALTIMEN	BIT(20)
+#define SRC_XTALCR_SXTALDIS	BIT(19)
+#define SRC_XTALCR_MXTALSTAT	BIT(2)
+#define SRC_XTALCR_MXTALEN	BIT(1)
+#define SRC_XTALCR_MXTALOVER	BIT(0)
+#define SRC_PLLCR		0x10U
+#define SRC_PLLCR_PLLTIMEN	BIT(29)
+#define SRC_PLLCR_PLL2EN	BIT(28)
+#define SRC_PLLCR_PLL1STAT	BIT(2)
+#define SRC_PLLCR_PLL1EN	BIT(1)
+#define SRC_PLLCR_PLL1OVER	BIT(0)
+#define SRC_PLLFR		0x14U
+#define SRC_PCKEN0		0x24U
+#define SRC_PCKDIS0		0x28U
+#define SRC_PCKENSR0		0x2CU
+#define SRC_PCKSR0		0x30U
+#define SRC_PCKEN1		0x34U
+#define SRC_PCKDIS1		0x38U
+#define SRC_PCKENSR1		0x3CU
+#define SRC_PCKSR1		0x40U
+
+/* Lock protecting the SRC_CR register */
+static DEFINE_SPINLOCK(src_lock);
+/* Base address of the SRC */
+static void __iomem *src_base;
+
+/**
+ * struct clk_pll1 - Nomadik PLL1 clock
+ * @hw: corresponding clock hardware entry
+ * @id: PLL instance: 1 or 2
+ */
+struct clk_pll {
+	struct clk_hw hw;
+	int id;
+};
+
+/**
+ * struct clk_src - Nomadik src clock
+ * @hw: corresponding clock hardware entry
+ * @id: the clock ID
+ * @group1: true if the clock is in group1, else it is in group0
+ * @clkbit: bit 0...31 corresponding to the clock in each clock register
+ */
+struct clk_src {
+	struct clk_hw hw;
+	int id;
+	bool group1;
+	u32 clkbit;
+};
+
+#define to_pll(_hw) container_of(_hw, struct clk_pll, hw)
+#define to_src(_hw) container_of(_hw, struct clk_src, hw)
+
+static int pll_clk_enable(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_pll(hw);
+	u32 val;
+
+	spin_lock(&src_lock);
+	val = readl(src_base + SRC_PLLCR);
+	if (pll->id == 1) {
+		if (val & SRC_PLLCR_PLL1OVER) {
+			val |= SRC_PLLCR_PLL1EN;
+			writel(val, src_base + SRC_PLLCR);
+		}
+	} else if (pll->id == 2) {
+		val |= SRC_PLLCR_PLL2EN;
+		writel(val, src_base + SRC_PLLCR);
+	}
+	spin_unlock(&src_lock);
+	return 0;
+}
+
+static void pll_clk_disable(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_pll(hw);
+	u32 val;
+
+	spin_lock(&src_lock);
+	val = readl(src_base + SRC_PLLCR);
+	if (pll->id == 1) {
+		if (val & SRC_PLLCR_PLL1OVER) {
+			val &= ~SRC_PLLCR_PLL1EN;
+			writel(val, src_base + SRC_PLLCR);
+		}
+	} else if (pll->id == 2) {
+		val &= ~SRC_PLLCR_PLL2EN;
+		writel(val, src_base + SRC_PLLCR);
+	}
+	spin_unlock(&src_lock);
+}
+
+static int pll_clk_is_enabled(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_pll(hw);
+	u32 val;
+
+	val = readl(src_base + SRC_PLLCR);
+	if (pll->id == 1) {
+		if (val & SRC_PLLCR_PLL1OVER)
+			return !!(val & SRC_PLLCR_PLL1EN);
+	} else if (pll->id == 2) {
+		return !!(val & SRC_PLLCR_PLL2EN);
+	}
+	return 1;
+}
+
+static unsigned long pll_clk_recalc_rate(struct clk_hw *hw,
+					  unsigned long parent_rate)
+{
+	struct clk_pll *pll = to_pll(hw);
+	u32 val;
+
+	val = readl(src_base + SRC_PLLFR);
+
+	if (pll->id == 1) {
+		u8 mul;
+		u8 div;
+
+		mul = (val >> 8) & 0x3FU;
+		mul += 2;
+		div = val & 0x07U;
+		return (parent_rate * mul) >> div;
+	}
+
+	if (pll->id == 2) {
+		u8 mul;
+
+		mul = (val >> 24) & 0x3FU;
+		mul += 2;
+		return (parent_rate * mul);
+	}
+
+	/* Unknown PLL */
+	return 0;
+}
+
+
+static const struct clk_ops pll_clk_ops = {
+	.enable = pll_clk_enable,
+	.disable = pll_clk_disable,
+	.is_enabled = pll_clk_is_enabled,
+	.recalc_rate = pll_clk_recalc_rate,
+};
+
+static struct clk * __init
+pll_clk_register(struct device *dev, const char *name,
+		 const char *parent_name, u32 id)
+{
+	struct clk *clk;
+	struct clk_pll *pll;
+	struct clk_init_data init;
+
+	if (id != 1 && id != 2) {
+		pr_err("%s: the Nomadik has only PLL 1 & 2\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+	if (!pll) {
+		pr_err("%s: could not allocate PLL clk\n", __func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	init.name = name;
+	init.ops = &pll_clk_ops;
+	init.parent_names = (parent_name ? &parent_name : NULL);
+	init.num_parents = (parent_name ? 1 : 0);
+	pll->hw.init = &init;
+	pll->id = id;
+
+	pr_debug("register PLL1 clock \"%s\"\n", name);
+
+	clk = clk_register(dev, &pll->hw);
+	if (IS_ERR(clk))
+		kfree(pll);
+
+	return clk;
+}
+
+/*
+ * The Nomadik SRC clocks are gated, but not in the sense that
+ * you read-modify-write a register. Instead there are separate
+ * clock enable and clock disable registers. Writing a '1' bit in
+ * the enable register for a certain clock ungates that clock without
+ * affecting the other clocks. The disable register works the opposite
+ * way.
  */
 
-static const __initconst struct of_device_id cpu8815_clk_match[] = {
-	{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
+static int src_clk_enable(struct clk_hw *hw)
+{
+	struct clk_src *sclk = to_src(hw);
+	u32 enreg = sclk->group1 ? SRC_PCKEN1 : SRC_PCKEN0;
+	u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0;
+
+	writel(sclk->clkbit, src_base + enreg);
+	/* spin until enabled */
+	while (!(readl(src_base + sreg) & sclk->clkbit))
+		cpu_relax();
+	return 0;
+}
+
+static void src_clk_disable(struct clk_hw *hw)
+{
+	struct clk_src *sclk = to_src(hw);
+	u32 disreg = sclk->group1 ? SRC_PCKDIS1 : SRC_PCKDIS0;
+	u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0;
+
+	writel(sclk->clkbit, src_base + disreg);
+	/* spin until disabled */
+	while (readl(src_base + sreg) & sclk->clkbit)
+		cpu_relax();
+}
+
+static int src_clk_is_enabled(struct clk_hw *hw)
+{
+	struct clk_src *sclk = to_src(hw);
+	u32 sreg = sclk->group1 ? SRC_PCKSR1 : SRC_PCKSR0;
+	u32 val = readl(src_base + sreg);
+
+	return !!(val & sclk->clkbit);
+}
+
+static unsigned long
+src_clk_recalc_rate(struct clk_hw *hw,
+		    unsigned long parent_rate)
+{
+	return parent_rate;
+}
+
+static const struct clk_ops src_clk_ops = {
+	.enable = src_clk_enable,
+	.disable = src_clk_disable,
+	.is_enabled = src_clk_is_enabled,
+	.recalc_rate = src_clk_recalc_rate,
+};
+
+static struct clk * __init
+src_clk_register(struct device *dev, const char *name,
+		 const char *parent_name, u8 id)
+{
+	struct clk *clk;
+	struct clk_src *sclk;
+	struct clk_init_data init;
+
+	sclk = kzalloc(sizeof(*sclk), GFP_KERNEL);
+	if (!sclk) {
+		pr_err("could not allocate SRC clock %s\n",
+			name);
+		return ERR_PTR(-ENOMEM);
+	}
+	init.name = name;
+	init.ops = &src_clk_ops;
+	/* Do not force-disable the static SDRAM controller */
+	if (id == 2)
+		init.flags = CLK_IGNORE_UNUSED;
+	else
+		init.flags = 0;
+	init.parent_names = (parent_name ? &parent_name : NULL);
+	init.num_parents = (parent_name ? 1 : 0);
+	sclk->hw.init = &init;
+	sclk->id = id;
+	sclk->group1 = (id > 31);
+	sclk->clkbit = BIT(id & 0x1f);
+
+	pr_debug("register clock \"%s\" ID: %d group: %d bits: %08x\n",
+		 name, id, sclk->group1, sclk->clkbit);
+
+	clk = clk_register(dev, &sclk->hw);
+	if (IS_ERR(clk))
+		kfree(sclk);
+
+	return clk;
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+static u32 src_pcksr0_boot;
+static u32 src_pcksr1_boot;
+
+static const char * const src_clk_names[] = {
+	"HCLKDMA0  ",
+	"HCLKSMC   ",
+	"HCLKSDRAM ",
+	"HCLKDMA1  ",
+	"HCLKCLCD  ",
+	"PCLKIRDA  ",
+	"PCLKSSP   ",
+	"PCLKUART0 ",
+	"PCLKSDI   ",
+	"PCLKI2C0  ",
+	"PCLKI2C1  ",
+	"PCLKUART1 ",
+	"PCLMSP0   ",
+	"HCLKUSB   ",
+	"HCLKDIF   ",
+	"HCLKSAA   ",
+	"HCLKSVA   ",
+	"PCLKHSI   ",
+	"PCLKXTI   ",
+	"PCLKUART2 ",
+	"PCLKMSP1  ",
+	"PCLKMSP2  ",
+	"PCLKOWM   ",
+	"HCLKHPI   ",
+	"PCLKSKE   ",
+	"PCLKHSEM  ",
+	"HCLK3D    ",
+	"HCLKHASH  ",
+	"HCLKCRYP  ",
+	"PCLKMSHC  ",
+	"HCLKUSBM  ",
+	"HCLKRNG   ",
+	"RESERVED  ",
+	"RESERVED  ",
+	"RESERVED  ",
+	"RESERVED  ",
+	"CLDCLK    ",
+	"IRDACLK   ",
+	"SSPICLK   ",
+	"UART0CLK  ",
+	"SDICLK    ",
+	"I2C0CLK   ",
+	"I2C1CLK   ",
+	"UART1CLK  ",
+	"MSPCLK0   ",
+	"USBCLK    ",
+	"DIFCLK    ",
+	"IPI2CCLK  ",
+	"IPBMCCLK  ",
+	"HSICLKRX  ",
+	"HSICLKTX  ",
+	"UART2CLK  ",
+	"MSPCLK1   ",
+	"MSPCLK2   ",
+	"OWMCLK    ",
+	"RESERVED  ",
+	"SKECLK    ",
+	"RESERVED  ",
+	"3DCLK     ",
+	"PCLKMSP3  ",
+	"MSPCLK3   ",
+	"MSHCCLK   ",
+	"USBMCLK   ",
+	"RNGCCLK   ",
+};
+
+static int nomadik_src_clk_show(struct seq_file *s, void *what)
+{
+	int i;
+	u32 src_pcksr0 = readl(src_base + SRC_PCKSR0);
+	u32 src_pcksr1 = readl(src_base + SRC_PCKSR1);
+	u32 src_pckensr0 = readl(src_base + SRC_PCKENSR0);
+	u32 src_pckensr1 = readl(src_base + SRC_PCKENSR1);
+
+	seq_printf(s, "Clock:      Boot:   Now:    Request: ASKED:\n");
+	for (i = 0; i < ARRAY_SIZE(src_clk_names); i++) {
+		u32 pcksrb = (i < 0x20) ? src_pcksr0_boot : src_pcksr1_boot;
+		u32 pcksr = (i < 0x20) ? src_pcksr0 : src_pcksr1;
+		u32 pckreq = (i < 0x20) ? src_pckensr0 : src_pckensr1;
+		u32 mask = BIT(i & 0x1f);
+
+		seq_printf(s, "%s  %s     %s     %s\n",
+			   src_clk_names[i],
+			   (pcksrb & mask) ? "on " : "off",
+			   (pcksr & mask) ? "on " : "off",
+			   (pckreq & mask) ? "on " : "off");
+	}
+	return 0;
+}
+
+static int nomadik_src_clk_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, nomadik_src_clk_show, NULL);
+}
+
+static const struct file_operations nomadik_src_clk_debugfs_ops = {
+	.open           = nomadik_src_clk_open,
+	.read           = seq_read,
+        .llseek         = seq_lseek,
+	.release        = single_release,
+};
+
+static int __init nomadik_src_clk_init_debugfs(void)
+{
+	src_pcksr0_boot = readl(src_base + SRC_PCKSR0);
+	src_pcksr1_boot = readl(src_base + SRC_PCKSR1);
+	debugfs_create_file("nomadik-src-clk", S_IFREG | S_IRUGO,
+			    NULL, NULL, &nomadik_src_clk_debugfs_ops);
+	return 0;
+}
+
+module_init(nomadik_src_clk_init_debugfs);
+
+#endif
+
+static void __init of_nomadik_pll_setup(struct device_node *np)
+{
+	struct clk *clk = ERR_PTR(-EINVAL);
+	const char *clk_name = np->name;
+	const char *parent_name;
+	u32 pll_id;
+
+	if (of_property_read_u32(np, "pll-id", &pll_id)) {
+		pr_err("%s: PLL \"%s\" missing pll-id property\n",
+			__func__, clk_name);
+		return;
+	}
+	parent_name = of_clk_get_parent_name(np, 0);
+	clk = pll_clk_register(NULL, clk_name, parent_name, pll_id);
+	if (!IS_ERR(clk))
+		of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+
+static void __init of_nomadik_hclk_setup(struct device_node *np)
+{
+	struct clk *clk = ERR_PTR(-EINVAL);
+	const char *clk_name = np->name;
+	const char *parent_name;
+
+	parent_name = of_clk_get_parent_name(np, 0);
+	/*
+	 * The HCLK divides PLL1 with 1 (passthru), 2, 3 or 4.
+	 */
+	clk = clk_register_divider(NULL, clk_name, parent_name,
+			   0, src_base + SRC_CR,
+			   13, 2,
+			   CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO,
+			   &src_lock);
+	if (!IS_ERR(clk))
+		of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+
+static void __init of_nomadik_src_clk_setup(struct device_node *np)
+{
+	struct clk *clk = ERR_PTR(-EINVAL);
+	const char *clk_name = np->name;
+	const char *parent_name;
+	u32 clk_id;
+
+	if (of_property_read_u32(np, "clock-id", &clk_id)) {
+		pr_err("%s: SRC clock \"%s\" missing clock-id property\n",
+			__func__, clk_name);
+		return;
+	}
+	parent_name = of_clk_get_parent_name(np, 0);
+	clk = src_clk_register(NULL, clk_name, parent_name, clk_id);
+	if (!IS_ERR(clk))
+		of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+
+static const __initconst struct of_device_id nomadik_src_match[] = {
+	{ .compatible = "stericsson,nomadik-src" },
 	{ /* sentinel */ }
 };
 
+static const __initconst struct of_device_id nomadik_src_clk_match[] = {
+	{
+		.compatible = "fixed-clock",
+		.data = of_fixed_clk_setup,
+	},
+	{
+		.compatible = "fixed-factor-clock",
+		.data = of_fixed_factor_clk_setup,
+	},
+	{
+		.compatible = "st,nomadik-pll-clock",
+		.data = of_nomadik_pll_setup,
+	},
+	{
+		.compatible = "st,nomadik-hclk-clock",
+		.data = of_nomadik_hclk_setup,
+	},
+	{
+		.compatible = "st,nomadik-src-clock",
+		.data = of_nomadik_src_clk_setup,
+	},
+	{ /* sentinel */ }
+};
+
+static int nomadik_clk_reboot_handler(struct notifier_block *this,
+				unsigned long code,
+				void *unused)
+{
+	u32 val;
+
+	/* The main chrystal need to be enabled for reboot to work */
+	val = readl(src_base + SRC_XTALCR);
+	val &= ~SRC_XTALCR_MXTALOVER;
+	val |= SRC_XTALCR_MXTALEN;
+	pr_crit("force-enabling MXTALO\n");
+	writel(val, src_base + SRC_XTALCR);
+	return NOTIFY_OK;
+}
+
+static struct notifier_block nomadik_clk_reboot_notifier = {
+	.notifier_call = nomadik_clk_reboot_handler,
+};
+
 void __init nomadik_clk_init(void)
 {
-	of_clk_init(cpu8815_clk_match);
+	struct device_node *np;
+	u32 val;
+
+	np = of_find_matching_node(NULL, nomadik_src_match);
+	if (!np) {
+		pr_crit("no matching node for SRC, aborting clock init\n");
+		return;
+	}
+	src_base = of_iomap(np, 0);
+	if (!src_base) {
+		pr_err("%s: must have src parent node with REGS (%s)\n",
+		       __func__, np->name);
+		return;
+	}
+	val = readl(src_base + SRC_XTALCR);
+	pr_info("SXTALO is %s\n",
+		(val & SRC_XTALCR_SXTALDIS) ? "disabled" : "enabled");
+	pr_info("MXTAL is %s\n",
+		(val & SRC_XTALCR_MXTALSTAT) ? "enabled" : "disabled");
+	if (of_property_read_bool(np, "disable-sxtalo")) {
+		/* The machine uses an external oscillator circuit */
+		val |= SRC_XTALCR_SXTALDIS;
+		pr_info("disabling SXTALO\n");
+	}
+	if (of_property_read_bool(np, "disable-mxtalo")) {
+		/* Disable this too: also run by external oscillator */
+		val |= SRC_XTALCR_MXTALOVER;
+		val &= ~SRC_XTALCR_MXTALEN;
+		pr_info("disabling MXTALO\n");
+	}
+	writel(val, src_base + SRC_XTALCR);
+	register_reboot_notifier(&nomadik_clk_reboot_notifier);
+
+	of_clk_init(nomadik_src_clk_match);
 }