| /* |
| * linux/arch/arm/mach-at91/clock.c |
| * |
| * Copyright (C) 2005 David Brownell |
| * Copyright (C) 2005 Ivan Kokshaysky |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/init.h> |
| #include <linux/fs.h> |
| #include <linux/debugfs.h> |
| #include <linux/seq_file.h> |
| #include <linux/list.h> |
| #include <linux/errno.h> |
| #include <linux/err.h> |
| #include <linux/spinlock.h> |
| #include <linux/delay.h> |
| #include <linux/clk.h> |
| #include <linux/io.h> |
| |
| #include <mach/hardware.h> |
| #include <mach/at91_pmc.h> |
| #include <mach/cpu.h> |
| |
| #include "clock.h" |
| |
| |
| /* |
| * There's a lot more which can be done with clocks, including cpufreq |
| * integration, slow clock mode support (for system suspend), letting |
| * PLLB be used at other rates (on boards that don't need USB), etc. |
| */ |
| |
| #define clk_is_primary(x) ((x)->type & CLK_TYPE_PRIMARY) |
| #define clk_is_programmable(x) ((x)->type & CLK_TYPE_PROGRAMMABLE) |
| #define clk_is_peripheral(x) ((x)->type & CLK_TYPE_PERIPHERAL) |
| #define clk_is_sys(x) ((x)->type & CLK_TYPE_SYSTEM) |
| |
| |
| /* |
| * Chips have some kind of clocks : group them by functionality |
| */ |
| #define cpu_has_utmi() ( cpu_is_at91cap9() \ |
| || cpu_is_at91sam9rl()) |
| |
| #define cpu_has_800M_plla() (cpu_is_at91sam9g20()) |
| |
| #define cpu_has_pllb() (!cpu_is_at91sam9rl()) |
| |
| #define cpu_has_upll() (0) |
| |
| /* USB host HS & FS */ |
| #define cpu_has_uhp() (!cpu_is_at91sam9rl()) |
| |
| /* USB device FS only */ |
| #define cpu_has_udpfs() (!cpu_is_at91sam9rl()) |
| |
| |
| static LIST_HEAD(clocks); |
| static DEFINE_SPINLOCK(clk_lock); |
| |
| static u32 at91_pllb_usb_init; |
| |
| /* |
| * Four primary clock sources: two crystal oscillators (32K, main), and |
| * two PLLs. PLLA usually runs the master clock; and PLLB must run at |
| * 48 MHz (unless no USB function clocks are needed). The main clock and |
| * both PLLs are turned off to run in "slow clock mode" (system suspend). |
| */ |
| static struct clk clk32k = { |
| .name = "clk32k", |
| .rate_hz = AT91_SLOW_CLOCK, |
| .users = 1, /* always on */ |
| .id = 0, |
| .type = CLK_TYPE_PRIMARY, |
| }; |
| static struct clk main_clk = { |
| .name = "main", |
| .pmc_mask = AT91_PMC_MOSCS, /* in PMC_SR */ |
| .id = 1, |
| .type = CLK_TYPE_PRIMARY, |
| }; |
| static struct clk plla = { |
| .name = "plla", |
| .parent = &main_clk, |
| .pmc_mask = AT91_PMC_LOCKA, /* in PMC_SR */ |
| .id = 2, |
| .type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL, |
| }; |
| |
| static void pllb_mode(struct clk *clk, int is_on) |
| { |
| u32 value; |
| |
| if (is_on) { |
| is_on = AT91_PMC_LOCKB; |
| value = at91_pllb_usb_init; |
| } else |
| value = 0; |
| |
| // REVISIT: Add work-around for AT91RM9200 Errata #26 ? |
| at91_sys_write(AT91_CKGR_PLLBR, value); |
| |
| do { |
| cpu_relax(); |
| } while ((at91_sys_read(AT91_PMC_SR) & AT91_PMC_LOCKB) != is_on); |
| } |
| |
| static struct clk pllb = { |
| .name = "pllb", |
| .parent = &main_clk, |
| .pmc_mask = AT91_PMC_LOCKB, /* in PMC_SR */ |
| .mode = pllb_mode, |
| .id = 3, |
| .type = CLK_TYPE_PRIMARY | CLK_TYPE_PLL, |
| }; |
| |
| static void pmc_sys_mode(struct clk *clk, int is_on) |
| { |
| if (is_on) |
| at91_sys_write(AT91_PMC_SCER, clk->pmc_mask); |
| else |
| at91_sys_write(AT91_PMC_SCDR, clk->pmc_mask); |
| } |
| |
| static void pmc_uckr_mode(struct clk *clk, int is_on) |
| { |
| unsigned int uckr = at91_sys_read(AT91_CKGR_UCKR); |
| |
| if (is_on) { |
| is_on = AT91_PMC_LOCKU; |
| at91_sys_write(AT91_CKGR_UCKR, uckr | clk->pmc_mask); |
| } else |
| at91_sys_write(AT91_CKGR_UCKR, uckr & ~(clk->pmc_mask)); |
| |
| do { |
| cpu_relax(); |
| } while ((at91_sys_read(AT91_PMC_SR) & AT91_PMC_LOCKU) != is_on); |
| } |
| |
| /* USB function clocks (PLLB must be 48 MHz) */ |
| static struct clk udpck = { |
| .name = "udpck", |
| .parent = &pllb, |
| .mode = pmc_sys_mode, |
| }; |
| static struct clk utmi_clk = { |
| .name = "utmi_clk", |
| .parent = &main_clk, |
| .pmc_mask = AT91_PMC_UPLLEN, /* in CKGR_UCKR */ |
| .mode = pmc_uckr_mode, |
| .type = CLK_TYPE_PLL, |
| }; |
| static struct clk uhpck = { |
| .name = "uhpck", |
| /*.parent = ... we choose parent at runtime */ |
| .mode = pmc_sys_mode, |
| }; |
| |
| |
| /* |
| * The master clock is divided from the CPU clock (by 1-4). It's used for |
| * memory, interfaces to on-chip peripherals, the AIC, and sometimes more |
| * (e.g baud rate generation). It's sourced from one of the primary clocks. |
| */ |
| static struct clk mck = { |
| .name = "mck", |
| .pmc_mask = AT91_PMC_MCKRDY, /* in PMC_SR */ |
| }; |
| |
| static void pmc_periph_mode(struct clk *clk, int is_on) |
| { |
| if (is_on) |
| at91_sys_write(AT91_PMC_PCER, clk->pmc_mask); |
| else |
| at91_sys_write(AT91_PMC_PCDR, clk->pmc_mask); |
| } |
| |
| static struct clk __init *at91_css_to_clk(unsigned long css) |
| { |
| switch (css) { |
| case AT91_PMC_CSS_SLOW: |
| return &clk32k; |
| case AT91_PMC_CSS_MAIN: |
| return &main_clk; |
| case AT91_PMC_CSS_PLLA: |
| return &plla; |
| case AT91_PMC_CSS_PLLB: |
| if (cpu_has_upll()) |
| /* CSS_PLLB == CSS_UPLL */ |
| return &utmi_clk; |
| else if (cpu_has_pllb()) |
| return &pllb; |
| } |
| |
| return NULL; |
| } |
| |
| /* |
| * Associate a particular clock with a function (eg, "uart") and device. |
| * The drivers can then request the same 'function' with several different |
| * devices and not care about which clock name to use. |
| */ |
| void __init at91_clock_associate(const char *id, struct device *dev, const char *func) |
| { |
| struct clk *clk = clk_get(NULL, id); |
| |
| if (!dev || !clk || !IS_ERR(clk_get(dev, func))) |
| return; |
| |
| clk->function = func; |
| clk->dev = dev; |
| } |
| |
| /* clocks cannot be de-registered no refcounting necessary */ |
| struct clk *clk_get(struct device *dev, const char *id) |
| { |
| struct clk *clk; |
| |
| list_for_each_entry(clk, &clocks, node) { |
| if (strcmp(id, clk->name) == 0) |
| return clk; |
| if (clk->function && (dev == clk->dev) && strcmp(id, clk->function) == 0) |
| return clk; |
| } |
| |
| return ERR_PTR(-ENOENT); |
| } |
| EXPORT_SYMBOL(clk_get); |
| |
| void clk_put(struct clk *clk) |
| { |
| } |
| EXPORT_SYMBOL(clk_put); |
| |
| static void __clk_enable(struct clk *clk) |
| { |
| if (clk->parent) |
| __clk_enable(clk->parent); |
| if (clk->users++ == 0 && clk->mode) |
| clk->mode(clk, 1); |
| } |
| |
| int clk_enable(struct clk *clk) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&clk_lock, flags); |
| __clk_enable(clk); |
| spin_unlock_irqrestore(&clk_lock, flags); |
| return 0; |
| } |
| EXPORT_SYMBOL(clk_enable); |
| |
| static void __clk_disable(struct clk *clk) |
| { |
| BUG_ON(clk->users == 0); |
| if (--clk->users == 0 && clk->mode) |
| clk->mode(clk, 0); |
| if (clk->parent) |
| __clk_disable(clk->parent); |
| } |
| |
| void clk_disable(struct clk *clk) |
| { |
| unsigned long flags; |
| |
| spin_lock_irqsave(&clk_lock, flags); |
| __clk_disable(clk); |
| spin_unlock_irqrestore(&clk_lock, flags); |
| } |
| EXPORT_SYMBOL(clk_disable); |
| |
| unsigned long clk_get_rate(struct clk *clk) |
| { |
| unsigned long flags; |
| unsigned long rate; |
| |
| spin_lock_irqsave(&clk_lock, flags); |
| for (;;) { |
| rate = clk->rate_hz; |
| if (rate || !clk->parent) |
| break; |
| clk = clk->parent; |
| } |
| spin_unlock_irqrestore(&clk_lock, flags); |
| return rate; |
| } |
| EXPORT_SYMBOL(clk_get_rate); |
| |
| /*------------------------------------------------------------------------*/ |
| |
| #ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS |
| |
| /* |
| * For now, only the programmable clocks support reparenting (MCK could |
| * do this too, with care) or rate changing (the PLLs could do this too, |
| * ditto MCK but that's more for cpufreq). Drivers may reparent to get |
| * a better rate match; we don't. |
| */ |
| |
| long clk_round_rate(struct clk *clk, unsigned long rate) |
| { |
| unsigned long flags; |
| unsigned prescale; |
| unsigned long actual; |
| |
| if (!clk_is_programmable(clk)) |
| return -EINVAL; |
| spin_lock_irqsave(&clk_lock, flags); |
| |
| actual = clk->parent->rate_hz; |
| for (prescale = 0; prescale < 7; prescale++) { |
| if (actual && actual <= rate) |
| break; |
| actual >>= 1; |
| } |
| |
| spin_unlock_irqrestore(&clk_lock, flags); |
| return (prescale < 7) ? actual : -ENOENT; |
| } |
| EXPORT_SYMBOL(clk_round_rate); |
| |
| int clk_set_rate(struct clk *clk, unsigned long rate) |
| { |
| unsigned long flags; |
| unsigned prescale; |
| unsigned long actual; |
| |
| if (!clk_is_programmable(clk)) |
| return -EINVAL; |
| if (clk->users) |
| return -EBUSY; |
| spin_lock_irqsave(&clk_lock, flags); |
| |
| actual = clk->parent->rate_hz; |
| for (prescale = 0; prescale < 7; prescale++) { |
| if (actual && actual <= rate) { |
| u32 pckr; |
| |
| pckr = at91_sys_read(AT91_PMC_PCKR(clk->id)); |
| pckr &= AT91_PMC_CSS; /* clock selection */ |
| pckr |= prescale << 2; |
| at91_sys_write(AT91_PMC_PCKR(clk->id), pckr); |
| clk->rate_hz = actual; |
| break; |
| } |
| actual >>= 1; |
| } |
| |
| spin_unlock_irqrestore(&clk_lock, flags); |
| return (prescale < 7) ? actual : -ENOENT; |
| } |
| EXPORT_SYMBOL(clk_set_rate); |
| |
| struct clk *clk_get_parent(struct clk *clk) |
| { |
| return clk->parent; |
| } |
| EXPORT_SYMBOL(clk_get_parent); |
| |
| int clk_set_parent(struct clk *clk, struct clk *parent) |
| { |
| unsigned long flags; |
| |
| if (clk->users) |
| return -EBUSY; |
| if (!clk_is_primary(parent) || !clk_is_programmable(clk)) |
| return -EINVAL; |
| spin_lock_irqsave(&clk_lock, flags); |
| |
| clk->rate_hz = parent->rate_hz; |
| clk->parent = parent; |
| at91_sys_write(AT91_PMC_PCKR(clk->id), parent->id); |
| |
| spin_unlock_irqrestore(&clk_lock, flags); |
| return 0; |
| } |
| EXPORT_SYMBOL(clk_set_parent); |
| |
| /* establish PCK0..PCKN parentage and rate */ |
| static void __init init_programmable_clock(struct clk *clk) |
| { |
| struct clk *parent; |
| u32 pckr; |
| |
| pckr = at91_sys_read(AT91_PMC_PCKR(clk->id)); |
| parent = at91_css_to_clk(pckr & AT91_PMC_CSS); |
| clk->parent = parent; |
| clk->rate_hz = parent->rate_hz / (1 << ((pckr & AT91_PMC_PRES) >> 2)); |
| } |
| |
| #endif /* CONFIG_AT91_PROGRAMMABLE_CLOCKS */ |
| |
| /*------------------------------------------------------------------------*/ |
| |
| #ifdef CONFIG_DEBUG_FS |
| |
| static int at91_clk_show(struct seq_file *s, void *unused) |
| { |
| u32 scsr, pcsr, uckr = 0, sr; |
| struct clk *clk; |
| |
| seq_printf(s, "SCSR = %8x\n", scsr = at91_sys_read(AT91_PMC_SCSR)); |
| seq_printf(s, "PCSR = %8x\n", pcsr = at91_sys_read(AT91_PMC_PCSR)); |
| seq_printf(s, "MOR = %8x\n", at91_sys_read(AT91_CKGR_MOR)); |
| seq_printf(s, "MCFR = %8x\n", at91_sys_read(AT91_CKGR_MCFR)); |
| seq_printf(s, "PLLA = %8x\n", at91_sys_read(AT91_CKGR_PLLAR)); |
| if (cpu_has_pllb()) |
| seq_printf(s, "PLLB = %8x\n", at91_sys_read(AT91_CKGR_PLLBR)); |
| if (cpu_has_utmi()) |
| seq_printf(s, "UCKR = %8x\n", uckr = at91_sys_read(AT91_CKGR_UCKR)); |
| seq_printf(s, "MCKR = %8x\n", at91_sys_read(AT91_PMC_MCKR)); |
| if (cpu_has_upll()) |
| seq_printf(s, "USB = %8x\n", at91_sys_read(AT91_PMC_USB)); |
| seq_printf(s, "SR = %8x\n", sr = at91_sys_read(AT91_PMC_SR)); |
| |
| seq_printf(s, "\n"); |
| |
| list_for_each_entry(clk, &clocks, node) { |
| char *state; |
| |
| if (clk->mode == pmc_sys_mode) |
| state = (scsr & clk->pmc_mask) ? "on" : "off"; |
| else if (clk->mode == pmc_periph_mode) |
| state = (pcsr & clk->pmc_mask) ? "on" : "off"; |
| else if (clk->mode == pmc_uckr_mode) |
| state = (uckr & clk->pmc_mask) ? "on" : "off"; |
| else if (clk->pmc_mask) |
| state = (sr & clk->pmc_mask) ? "on" : "off"; |
| else if (clk == &clk32k || clk == &main_clk) |
| state = "on"; |
| else |
| state = ""; |
| |
| seq_printf(s, "%-10s users=%2d %-3s %9ld Hz %s\n", |
| clk->name, clk->users, state, clk_get_rate(clk), |
| clk->parent ? clk->parent->name : ""); |
| } |
| return 0; |
| } |
| |
| static int at91_clk_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, at91_clk_show, NULL); |
| } |
| |
| static const struct file_operations at91_clk_operations = { |
| .open = at91_clk_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = single_release, |
| }; |
| |
| static int __init at91_clk_debugfs_init(void) |
| { |
| /* /sys/kernel/debug/at91_clk */ |
| (void) debugfs_create_file("at91_clk", S_IFREG | S_IRUGO, NULL, NULL, &at91_clk_operations); |
| |
| return 0; |
| } |
| postcore_initcall(at91_clk_debugfs_init); |
| |
| #endif |
| |
| /*------------------------------------------------------------------------*/ |
| |
| /* Register a new clock */ |
| int __init clk_register(struct clk *clk) |
| { |
| if (clk_is_peripheral(clk)) { |
| clk->parent = &mck; |
| clk->mode = pmc_periph_mode; |
| list_add_tail(&clk->node, &clocks); |
| } |
| else if (clk_is_sys(clk)) { |
| clk->parent = &mck; |
| clk->mode = pmc_sys_mode; |
| |
| list_add_tail(&clk->node, &clocks); |
| } |
| #ifdef CONFIG_AT91_PROGRAMMABLE_CLOCKS |
| else if (clk_is_programmable(clk)) { |
| clk->mode = pmc_sys_mode; |
| init_programmable_clock(clk); |
| list_add_tail(&clk->node, &clocks); |
| } |
| #endif |
| |
| return 0; |
| } |
| |
| |
| /*------------------------------------------------------------------------*/ |
| |
| static u32 __init at91_pll_rate(struct clk *pll, u32 freq, u32 reg) |
| { |
| unsigned mul, div; |
| |
| div = reg & 0xff; |
| mul = (reg >> 16) & 0x7ff; |
| if (div && mul) { |
| freq /= div; |
| freq *= mul + 1; |
| } else |
| freq = 0; |
| |
| return freq; |
| } |
| |
| static u32 __init at91_usb_rate(struct clk *pll, u32 freq, u32 reg) |
| { |
| if (pll == &pllb && (reg & AT91_PMC_USB96M)) |
| return freq / 2; |
| else |
| return freq; |
| } |
| |
| static unsigned __init at91_pll_calc(unsigned main_freq, unsigned out_freq) |
| { |
| unsigned i, div = 0, mul = 0, diff = 1 << 30; |
| unsigned ret = (out_freq > 155000000) ? 0xbe00 : 0x3e00; |
| |
| /* PLL output max 240 MHz (or 180 MHz per errata) */ |
| if (out_freq > 240000000) |
| goto fail; |
| |
| for (i = 1; i < 256; i++) { |
| int diff1; |
| unsigned input, mul1; |
| |
| /* |
| * PLL input between 1MHz and 32MHz per spec, but lower |
| * frequences seem necessary in some cases so allow 100K. |
| * Warning: some newer products need 2MHz min. |
| */ |
| input = main_freq / i; |
| if (cpu_is_at91sam9g20() && input < 2000000) |
| continue; |
| if (input < 100000) |
| continue; |
| if (input > 32000000) |
| continue; |
| |
| mul1 = out_freq / input; |
| if (cpu_is_at91sam9g20() && mul > 63) |
| continue; |
| if (mul1 > 2048) |
| continue; |
| if (mul1 < 2) |
| goto fail; |
| |
| diff1 = out_freq - input * mul1; |
| if (diff1 < 0) |
| diff1 = -diff1; |
| if (diff > diff1) { |
| diff = diff1; |
| div = i; |
| mul = mul1; |
| if (diff == 0) |
| break; |
| } |
| } |
| if (i == 256 && diff > (out_freq >> 5)) |
| goto fail; |
| return ret | ((mul - 1) << 16) | div; |
| fail: |
| return 0; |
| } |
| |
| static struct clk *const standard_pmc_clocks[] __initdata = { |
| /* four primary clocks */ |
| &clk32k, |
| &main_clk, |
| &plla, |
| |
| /* MCK */ |
| &mck |
| }; |
| |
| /* PLLB generated USB full speed clock init */ |
| static void __init at91_pllb_usbfs_clock_init(unsigned long main_clock) |
| { |
| /* |
| * USB clock init: choose 48 MHz PLLB value, |
| * disable 48MHz clock during usb peripheral suspend. |
| * |
| * REVISIT: assumes MCK doesn't derive from PLLB! |
| */ |
| uhpck.parent = &pllb; |
| |
| at91_pllb_usb_init = at91_pll_calc(main_clock, 48000000 * 2) | AT91_PMC_USB96M; |
| pllb.rate_hz = at91_pll_rate(&pllb, main_clock, at91_pllb_usb_init); |
| if (cpu_is_at91rm9200()) { |
| uhpck.pmc_mask = AT91RM9200_PMC_UHP; |
| udpck.pmc_mask = AT91RM9200_PMC_UDP; |
| at91_sys_write(AT91_PMC_SCER, AT91RM9200_PMC_MCKUDP); |
| } else if (cpu_is_at91sam9260() || cpu_is_at91sam9261() || cpu_is_at91sam9263() || cpu_is_at91sam9g20()) { |
| uhpck.pmc_mask = AT91SAM926x_PMC_UHP; |
| udpck.pmc_mask = AT91SAM926x_PMC_UDP; |
| } else if (cpu_is_at91cap9()) { |
| uhpck.pmc_mask = AT91CAP9_PMC_UHP; |
| } |
| at91_sys_write(AT91_CKGR_PLLBR, 0); |
| |
| udpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init); |
| uhpck.rate_hz = at91_usb_rate(&pllb, pllb.rate_hz, at91_pllb_usb_init); |
| } |
| |
| /* UPLL generated USB full speed clock init */ |
| static void __init at91_upll_usbfs_clock_init(unsigned long main_clock) |
| { |
| /* |
| * USB clock init: choose 480 MHz from UPLL, |
| */ |
| unsigned int usbr = AT91_PMC_USBS_UPLL; |
| |
| /* Setup divider by 10 to reach 48 MHz */ |
| usbr |= ((10 - 1) << 8) & AT91_PMC_OHCIUSBDIV; |
| |
| at91_sys_write(AT91_PMC_USB, usbr); |
| |
| /* Now set uhpck values */ |
| uhpck.parent = &utmi_clk; |
| uhpck.pmc_mask = AT91SAM926x_PMC_UHP; |
| uhpck.rate_hz = utmi_clk.parent->rate_hz; |
| uhpck.rate_hz /= 1 + ((at91_sys_read(AT91_PMC_USB) & AT91_PMC_OHCIUSBDIV) >> 8); |
| } |
| |
| int __init at91_clock_init(unsigned long main_clock) |
| { |
| unsigned tmp, freq, mckr; |
| int i; |
| |
| /* |
| * When the bootloader initialized the main oscillator correctly, |
| * there's no problem using the cycle counter. But if it didn't, |
| * or when using oscillator bypass mode, we must be told the speed |
| * of the main clock. |
| */ |
| if (!main_clock) { |
| do { |
| tmp = at91_sys_read(AT91_CKGR_MCFR); |
| } while (!(tmp & AT91_PMC_MAINRDY)); |
| main_clock = (tmp & AT91_PMC_MAINF) * (AT91_SLOW_CLOCK / 16); |
| } |
| main_clk.rate_hz = main_clock; |
| |
| /* report if PLLA is more than mildly overclocked */ |
| plla.rate_hz = at91_pll_rate(&plla, main_clock, at91_sys_read(AT91_CKGR_PLLAR)); |
| if ((!cpu_has_800M_plla() && plla.rate_hz > 209000000) |
| || (cpu_has_800M_plla() && plla.rate_hz > 800000000)) |
| pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000); |
| |
| |
| if (cpu_has_upll() && !cpu_has_pllb()) { |
| /* setup UTMI clock as the fourth primary clock |
| * (instead of pllb) */ |
| utmi_clk.type |= CLK_TYPE_PRIMARY; |
| utmi_clk.id = 3; |
| } |
| |
| |
| /* |
| * USB HS clock init |
| */ |
| if (cpu_has_utmi()) |
| /* |
| * multiplier is hard-wired to 40 |
| * (obtain the USB High Speed 480 MHz when input is 12 MHz) |
| */ |
| utmi_clk.rate_hz = 40 * utmi_clk.parent->rate_hz; |
| |
| /* |
| * USB FS clock init |
| */ |
| if (cpu_has_pllb()) |
| at91_pllb_usbfs_clock_init(main_clock); |
| if (cpu_has_upll()) |
| /* assumes that we choose UPLL for USB and not PLLA */ |
| at91_upll_usbfs_clock_init(main_clock); |
| |
| /* |
| * MCK and CPU derive from one of those primary clocks. |
| * For now, assume this parentage won't change. |
| */ |
| mckr = at91_sys_read(AT91_PMC_MCKR); |
| mck.parent = at91_css_to_clk(mckr & AT91_PMC_CSS); |
| freq = mck.parent->rate_hz; |
| freq /= (1 << ((mckr & AT91_PMC_PRES) >> 2)); /* prescale */ |
| if (cpu_is_at91rm9200()) { |
| mck.rate_hz = freq / (1 + ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */ |
| } else if (cpu_is_at91sam9g20()) { |
| mck.rate_hz = (mckr & AT91_PMC_MDIV) ? |
| freq / ((mckr & AT91_PMC_MDIV) >> 7) : freq; /* mdiv ; (x >> 7) = ((x >> 8) * 2) */ |
| if (mckr & AT91_PMC_PDIV) |
| freq /= 2; /* processor clock division */ |
| } else { |
| mck.rate_hz = freq / (1 << ((mckr & AT91_PMC_MDIV) >> 8)); /* mdiv */ |
| } |
| |
| /* Register the PMC's standard clocks */ |
| for (i = 0; i < ARRAY_SIZE(standard_pmc_clocks); i++) |
| list_add_tail(&standard_pmc_clocks[i]->node, &clocks); |
| |
| if (cpu_has_pllb()) |
| list_add_tail(&pllb.node, &clocks); |
| |
| if (cpu_has_uhp()) |
| list_add_tail(&uhpck.node, &clocks); |
| |
| if (cpu_has_udpfs()) |
| list_add_tail(&udpck.node, &clocks); |
| |
| if (cpu_has_utmi()) |
| list_add_tail(&utmi_clk.node, &clocks); |
| |
| /* MCK and CPU clock are "always on" */ |
| clk_enable(&mck); |
| |
| printk("Clocks: CPU %u MHz, master %u MHz, main %u.%03u MHz\n", |
| freq / 1000000, (unsigned) mck.rate_hz / 1000000, |
| (unsigned) main_clock / 1000000, |
| ((unsigned) main_clock % 1000000) / 1000); |
| |
| return 0; |
| } |
| |
| /* |
| * Several unused clocks may be active. Turn them off. |
| */ |
| static int __init at91_clock_reset(void) |
| { |
| unsigned long pcdr = 0; |
| unsigned long scdr = 0; |
| struct clk *clk; |
| |
| list_for_each_entry(clk, &clocks, node) { |
| if (clk->users > 0) |
| continue; |
| |
| if (clk->mode == pmc_periph_mode) |
| pcdr |= clk->pmc_mask; |
| |
| if (clk->mode == pmc_sys_mode) |
| scdr |= clk->pmc_mask; |
| |
| pr_debug("Clocks: disable unused %s\n", clk->name); |
| } |
| |
| at91_sys_write(AT91_PMC_PCDR, pcdr); |
| at91_sys_write(AT91_PMC_SCDR, scdr); |
| |
| return 0; |
| } |
| late_initcall(at91_clock_reset); |