1 files changed, 644 insertions, 0 deletions

diff --git a/arch/arm/mach-at91/clock.c b/arch/arm/mach-at91/clock.c
new file mode 100644
index 000000000000..baab095f6e32
--- /dev/null
+++ b/arch/arm/mach-at91/clock.c
@@ -0,0 +1,644 @@
+/*
+ * 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 <asm/semaphore.h>
+#include <asm/io.h>
+#include <asm/mach-types.h>
+
+#include <asm/hardware.h>
+#include <asm/arch/at91_pmc.h>
+#include <asm/arch/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)
+
+
+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);
+}
+
+/* USB function clocks (PLLB must be 48 MHz) */
+static struct clk udpck = {
+        .name           = "udpck",
+        .parent         = &pllb,
+        .mode           = pmc_sys_mode,
+};
+static struct clk uhpck = {
+        .name           = "uhpck",
+        .parent         = &pllb,
+        .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:
+                        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_PLLB;      /* 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..PCK3 parentage and rate */
+static void 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 >> 2) & 3));
+}
+
+#endif  /* CONFIG_AT91_PROGRAMMABLE_CLOCKS */
+
+/*------------------------------------------------------------------------*/
+
+#ifdef CONFIG_DEBUG_FS
+
+static int at91_clk_show(struct seq_file *s, void *unused)
+{
+        u32             scsr, pcsr, sr;
+        struct clk      *clk;
+        unsigned        i;
+
+        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));
+        seq_printf(s, "PLLB = %8x\n", at91_sys_read(AT91_CKGR_PLLBR));
+
+        seq_printf(s, "MCKR = %8x\n", at91_sys_read(AT91_PMC_MCKR));
+        for (i = 0; i < 4; i++)
+                seq_printf(s, "PCK%d = %8x\n", i, at91_sys_read(AT91_PMC_PCKR(i)));
+        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->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 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.
+                 */
+                input = main_freq / i;
+                if (input < 100000)
+                        continue;
+                if (input > 32000000)
+                        continue;
+
+                mul1 = out_freq / input;
+                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;
+}
+
+/*
+ * Several unused clocks may be active.  Turn them off.
+ */
+static void __init at91_periphclk_reset(void)
+{
+        unsigned long reg;
+        struct clk *clk;
+
+        reg = at91_sys_read(AT91_PMC_PCSR);
+
+        list_for_each_entry(clk, &clocks, node) {
+                if (clk->mode != pmc_periph_mode)
+                        continue;
+
+                if (clk->users > 0)
+                        reg &= ~clk->pmc_mask;
+        }
+
+        at91_sys_write(AT91_PMC_PCDR, reg);
+}
+
+static struct clk *const standard_pmc_clocks[] __initdata = {
+        /* four primary clocks */
+        &clk32k,
+        &main_clk,
+        &plla,
+        &pllb,
+
+        /* PLLB children (USB) */
+        &udpck,
+        &uhpck,
+
+        /* MCK */
+        &mck
+};
+
+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 (plla.rate_hz > 209000000)
+                pr_info("Clocks: PLLA overclocked, %ld MHz\n", plla.rate_hz / 1000000);
+
+        /*
+         * USB clock init:  choose 48 MHz PLLB value, turn all clocks off,
+         * disable 48MHz clock during usb peripheral suspend.
+         *
+         * REVISIT:  assumes MCK doesn't derive from 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_SCDR, AT91RM9200_PMC_UHP | AT91RM9200_PMC_UDP);
+                at91_sys_write(AT91_PMC_SCER, AT91RM9200_PMC_MCKUDP);
+        } else if (cpu_is_at91sam9260()) {
+                uhpck.pmc_mask = AT91SAM926x_PMC_UHP;
+                udpck.pmc_mask = AT91SAM926x_PMC_UDP;
+                at91_sys_write(AT91_PMC_SCDR, AT91SAM926x_PMC_UHP | AT91SAM926x_PMC_UDP);
+        } else if (cpu_is_at91sam9261()) {
+                uhpck.pmc_mask = (AT91SAM926x_PMC_UHP | AT91_PMC_HCK0);
+                udpck.pmc_mask = AT91SAM926x_PMC_UDP;
+                at91_sys_write(AT91_PMC_SCDR, AT91SAM926x_PMC_UHP | AT91_PMC_HCK0 | AT91SAM926x_PMC_UDP);
+        }
+        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);
+
+        /*
+         * 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 >> 2) & 3));               /* prescale */
+        mck.rate_hz = freq / (1 + ((mckr >> 8) & 3));   /* 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);
+
+        /* 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);
+
+        /* disable all programmable clocks */
+        at91_sys_write(AT91_PMC_SCDR, AT91_PMC_PCK0 | AT91_PMC_PCK1 | AT91_PMC_PCK2 | AT91_PMC_PCK3);
+
+        /* disable all other unused peripheral clocks */
+        at91_periphclk_reset();
+
+        return 0;
+}