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Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/clk-nomadik.c | 567 |
1 files changed, 567 insertions, 0 deletions
diff --git a/drivers/clk/clk-nomadik.c b/drivers/clk/clk-nomadik.c new file mode 100644 index 000000000..bad2677e1 --- /dev/null +++ b/drivers/clk/clk-nomadik.c @@ -0,0 +1,567 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Nomadik clock implementation + * Copyright (C) 2013 ST-Ericsson AB + * 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 (%pOFn)\n", + __func__, np); + 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_debugfs_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; +} + +DEFINE_SHOW_ATTRIBUTE(nomadik_src_clk_debugfs); + +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_fops); + 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); |