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path: root/drivers/clk/clk-nomadik.c
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-rw-r--r--drivers/clk/clk-nomadik.c577
1 files changed, 577 insertions, 0 deletions
diff --git a/drivers/clk/clk-nomadik.c b/drivers/clk/clk-nomadik.c
new file mode 100644
index 000000000..13ad6d1e5
--- /dev/null
+++ b/drivers/clk/clk-nomadik.c
@@ -0,0 +1,577 @@
+/*
+ * 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/slab.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_CR_T0_ENSEL BIT(15)
+#define SRC_CR_T1_ENSEL BIT(17)
+#define SRC_CR_T2_ENSEL BIT(19)
+#define SRC_CR_T3_ENSEL BIT(21)
+#define SRC_CR_T4_ENSEL BIT(23)
+#define SRC_CR_T5_ENSEL BIT(25)
+#define SRC_CR_T6_ENSEL BIT(27)
+#define SRC_CR_T7_ENSEL BIT(29)
+#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;
+
+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,
+};
+
+static const struct of_device_id nomadik_src_match[] __initconst = {
+ { .compatible = "stericsson,nomadik-src" },
+ { /* sentinel */ }
+};
+
+static void __init nomadik_src_init(void)
+{
+ 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;
+ }
+
+ /* Set all timers to use the 2.4 MHz TIMCLK */
+ val = readl(src_base + SRC_CR);
+ val |= SRC_CR_T0_ENSEL;
+ val |= SRC_CR_T1_ENSEL;
+ val |= SRC_CR_T2_ENSEL;
+ val |= SRC_CR_T3_ENSEL;
+ val |= SRC_CR_T4_ENSEL;
+ val |= SRC_CR_T5_ENSEL;
+ val |= SRC_CR_T6_ENSEL;
+ val |= SRC_CR_T7_ENSEL;
+ writel(val, src_base + SRC_CR);
+
+ 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);
+}
+
+/**
+ * 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_hw * __init
+pll_clk_register(struct device *dev, const char *name,
+ const char *parent_name, u32 id)
+{
+ int ret;
+ 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)
+ 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);
+
+ ret = clk_hw_register(dev, &pll->hw);
+ if (ret) {
+ kfree(pll);
+ return ERR_PTR(ret);
+ }
+
+ return &pll->hw;
+}
+
+/*
+ * 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 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_hw * __init
+src_clk_register(struct device *dev, const char *name,
+ const char *parent_name, u8 id)
+{
+ int ret;
+ struct clk_src *sclk;
+ struct clk_init_data init;
+
+ sclk = kzalloc(sizeof(*sclk), GFP_KERNEL);
+ if (!sclk)
+ 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);
+
+ ret = clk_hw_register(dev, &sclk->hw);
+ if (ret) {
+ kfree(sclk);
+ return ERR_PTR(ret);
+ }
+
+ return &sclk->hw;
+}
+
+#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_puts(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)
+{
+ /* Vital for multiplatform */
+ if (!src_base)
+ return -ENODEV;
+ 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;
+}
+device_initcall(nomadik_src_clk_init_debugfs);
+
+#endif
+
+static void __init of_nomadik_pll_setup(struct device_node *np)
+{
+ struct clk_hw *hw;
+ const char *clk_name = np->name;
+ const char *parent_name;
+ u32 pll_id;
+
+ if (!src_base)
+ nomadik_src_init();
+
+ 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);
+ hw = pll_clk_register(NULL, clk_name, parent_name, pll_id);
+ if (!IS_ERR(hw))
+ of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+}
+CLK_OF_DECLARE(nomadik_pll_clk,
+ "st,nomadik-pll-clock", of_nomadik_pll_setup);
+
+static void __init of_nomadik_hclk_setup(struct device_node *np)
+{
+ struct clk_hw *hw;
+ const char *clk_name = np->name;
+ const char *parent_name;
+
+ if (!src_base)
+ nomadik_src_init();
+
+ parent_name = of_clk_get_parent_name(np, 0);
+ /*
+ * The HCLK divides PLL1 with 1 (passthru), 2, 3 or 4.
+ */
+ hw = clk_hw_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(hw))
+ of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+}
+CLK_OF_DECLARE(nomadik_hclk_clk,
+ "st,nomadik-hclk-clock", of_nomadik_hclk_setup);
+
+static void __init of_nomadik_src_clk_setup(struct device_node *np)
+{
+ struct clk_hw *hw;
+ const char *clk_name = np->name;
+ const char *parent_name;
+ u32 clk_id;
+
+ if (!src_base)
+ nomadik_src_init();
+
+ 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);
+ hw = src_clk_register(NULL, clk_name, parent_name, clk_id);
+ if (!IS_ERR(hw))
+ of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+}
+CLK_OF_DECLARE(nomadik_src_clk,
+ "st,nomadik-src-clock", of_nomadik_src_clk_setup);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-23 15:47:32 +0000