summaryrefslogtreecommitdiffstats
path: root/arch/arm/mach-omap2/clock34xx.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-omap2/clock34xx.c')
-rw-r--r--arch/arm/mach-omap2/clock34xx.c526
1 files changed, 526 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/clock34xx.c b/arch/arm/mach-omap2/clock34xx.c
new file mode 100644
index 00000000000..4263099b1ad
--- /dev/null
+++ b/arch/arm/mach-omap2/clock34xx.c
@@ -0,0 +1,526 @@
+/*
+ * OMAP3-specific clock framework functions
+ *
+ * Copyright (C) 2007-2008 Texas Instruments, Inc.
+ * Copyright (C) 2007-2008 Nokia Corporation
+ *
+ * Written by Paul Walmsley
+ * Testing and integration fixes by Jouni Högander
+ *
+ * Parts of this code are based on code written by
+ * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#undef DEBUG
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/delay.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/limits.h>
+
+#include <asm/arch/clock.h>
+#include <asm/arch/sram.h>
+#include <asm/div64.h>
+#include <asm/bitops.h>
+
+#include "memory.h"
+#include "clock.h"
+#include "clock34xx.h"
+#include "prm.h"
+#include "prm-regbits-34xx.h"
+#include "cm.h"
+#include "cm-regbits-34xx.h"
+
+/* CM_AUTOIDLE_PLL*.AUTO_* bit values */
+#define DPLL_AUTOIDLE_DISABLE 0x0
+#define DPLL_AUTOIDLE_LOW_POWER_STOP 0x1
+
+#define MAX_DPLL_WAIT_TRIES 1000000
+
+/**
+ * omap3_dpll_recalc - recalculate DPLL rate
+ * @clk: DPLL struct clk
+ *
+ * Recalculate and propagate the DPLL rate.
+ */
+static void omap3_dpll_recalc(struct clk *clk)
+{
+ clk->rate = omap2_get_dpll_rate(clk);
+
+ propagate_rate(clk);
+}
+
+/* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
+static void _omap3_dpll_write_clken(struct clk *clk, u8 clken_bits)
+{
+ const struct dpll_data *dd;
+
+ dd = clk->dpll_data;
+
+ cm_rmw_reg_bits(dd->enable_mask, clken_bits << __ffs(dd->enable_mask),
+ dd->control_reg);
+}
+
+/* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */
+static int _omap3_wait_dpll_status(struct clk *clk, u8 state)
+{
+ const struct dpll_data *dd;
+ int i = 0;
+ int ret = -EINVAL;
+ u32 idlest_mask;
+
+ dd = clk->dpll_data;
+
+ state <<= dd->idlest_bit;
+ idlest_mask = 1 << dd->idlest_bit;
+
+ while (((cm_read_reg(dd->idlest_reg) & idlest_mask) != state) &&
+ i < MAX_DPLL_WAIT_TRIES) {
+ i++;
+ udelay(1);
+ }
+
+ if (i == MAX_DPLL_WAIT_TRIES) {
+ printk(KERN_ERR "clock: %s failed transition to '%s'\n",
+ clk->name, (state) ? "locked" : "bypassed");
+ } else {
+ pr_debug("clock: %s transition to '%s' in %d loops\n",
+ clk->name, (state) ? "locked" : "bypassed", i);
+
+ ret = 0;
+ }
+
+ return ret;
+}
+
+/* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
+
+/*
+ * _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
+ * @clk: pointer to a DPLL struct clk
+ *
+ * Instructs a non-CORE DPLL to lock. Waits for the DPLL to report
+ * readiness before returning. Will save and restore the DPLL's
+ * autoidle state across the enable, per the CDP code. If the DPLL
+ * locked successfully, return 0; if the DPLL did not lock in the time
+ * allotted, or DPLL3 was passed in, return -EINVAL.
+ */
+static int _omap3_noncore_dpll_lock(struct clk *clk)
+{
+ u8 ai;
+ int r;
+
+ if (clk == &dpll3_ck)
+ return -EINVAL;
+
+ pr_debug("clock: locking DPLL %s\n", clk->name);
+
+ ai = omap3_dpll_autoidle_read(clk);
+
+ _omap3_dpll_write_clken(clk, DPLL_LOCKED);
+
+ if (ai) {
+ /*
+ * If no downstream clocks are enabled, CM_IDLEST bit
+ * may never become active, so don't wait for DPLL to lock.
+ */
+ r = 0;
+ omap3_dpll_allow_idle(clk);
+ } else {
+ r = _omap3_wait_dpll_status(clk, 1);
+ omap3_dpll_deny_idle(clk);
+ };
+
+ return r;
+}
+
+/*
+ * omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
+ * @clk: pointer to a DPLL struct clk
+ *
+ * Instructs a non-CORE DPLL to enter low-power bypass mode. In
+ * bypass mode, the DPLL's rate is set equal to its parent clock's
+ * rate. Waits for the DPLL to report readiness before returning.
+ * Will save and restore the DPLL's autoidle state across the enable,
+ * per the CDP code. If the DPLL entered bypass mode successfully,
+ * return 0; if the DPLL did not enter bypass in the time allotted, or
+ * DPLL3 was passed in, or the DPLL does not support low-power bypass,
+ * return -EINVAL.
+ */
+static int _omap3_noncore_dpll_bypass(struct clk *clk)
+{
+ int r;
+ u8 ai;
+
+ if (clk == &dpll3_ck)
+ return -EINVAL;
+
+ if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS)))
+ return -EINVAL;
+
+ pr_debug("clock: configuring DPLL %s for low-power bypass\n",
+ clk->name);
+
+ ai = omap3_dpll_autoidle_read(clk);
+
+ _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS);
+
+ r = _omap3_wait_dpll_status(clk, 0);
+
+ if (ai)
+ omap3_dpll_allow_idle(clk);
+ else
+ omap3_dpll_deny_idle(clk);
+
+ return r;
+}
+
+/*
+ * _omap3_noncore_dpll_stop - instruct a DPLL to stop
+ * @clk: pointer to a DPLL struct clk
+ *
+ * Instructs a non-CORE DPLL to enter low-power stop. Will save and
+ * restore the DPLL's autoidle state across the stop, per the CDP
+ * code. If DPLL3 was passed in, or the DPLL does not support
+ * low-power stop, return -EINVAL; otherwise, return 0.
+ */
+static int _omap3_noncore_dpll_stop(struct clk *clk)
+{
+ u8 ai;
+
+ if (clk == &dpll3_ck)
+ return -EINVAL;
+
+ if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP)))
+ return -EINVAL;
+
+ pr_debug("clock: stopping DPLL %s\n", clk->name);
+
+ ai = omap3_dpll_autoidle_read(clk);
+
+ _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP);
+
+ if (ai)
+ omap3_dpll_allow_idle(clk);
+ else
+ omap3_dpll_deny_idle(clk);
+
+ return 0;
+}
+
+/**
+ * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
+ * @clk: pointer to a DPLL struct clk
+ *
+ * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
+ * The choice of modes depends on the DPLL's programmed rate: if it is
+ * the same as the DPLL's parent clock, it will enter bypass;
+ * otherwise, it will enter lock. This code will wait for the DPLL to
+ * indicate readiness before returning, unless the DPLL takes too long
+ * to enter the target state. Intended to be used as the struct clk's
+ * enable function. If DPLL3 was passed in, or the DPLL does not
+ * support low-power stop, or if the DPLL took too long to enter
+ * bypass or lock, return -EINVAL; otherwise, return 0.
+ */
+static int omap3_noncore_dpll_enable(struct clk *clk)
+{
+ int r;
+
+ if (clk == &dpll3_ck)
+ return -EINVAL;
+
+ if (clk->parent->rate == clk_get_rate(clk))
+ r = _omap3_noncore_dpll_bypass(clk);
+ else
+ r = _omap3_noncore_dpll_lock(clk);
+
+ return r;
+}
+
+/**
+ * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
+ * @clk: pointer to a DPLL struct clk
+ *
+ * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
+ * The choice of modes depends on the DPLL's programmed rate: if it is
+ * the same as the DPLL's parent clock, it will enter bypass;
+ * otherwise, it will enter lock. This code will wait for the DPLL to
+ * indicate readiness before returning, unless the DPLL takes too long
+ * to enter the target state. Intended to be used as the struct clk's
+ * enable function. If DPLL3 was passed in, or the DPLL does not
+ * support low-power stop, or if the DPLL took too long to enter
+ * bypass or lock, return -EINVAL; otherwise, return 0.
+ */
+static void omap3_noncore_dpll_disable(struct clk *clk)
+{
+ if (clk == &dpll3_ck)
+ return;
+
+ _omap3_noncore_dpll_stop(clk);
+}
+
+/**
+ * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
+ * @clk: struct clk * of the DPLL to read
+ *
+ * Return the DPLL's autoidle bits, shifted down to bit 0. Returns
+ * -EINVAL if passed a null pointer or if the struct clk does not
+ * appear to refer to a DPLL.
+ */
+static u32 omap3_dpll_autoidle_read(struct clk *clk)
+{
+ const struct dpll_data *dd;
+ u32 v;
+
+ if (!clk || !clk->dpll_data)
+ return -EINVAL;
+
+ dd = clk->dpll_data;
+
+ v = cm_read_reg(dd->autoidle_reg);
+ v &= dd->autoidle_mask;
+ v >>= __ffs(dd->autoidle_mask);
+
+ return v;
+}
+
+/**
+ * omap3_dpll_allow_idle - enable DPLL autoidle bits
+ * @clk: struct clk * of the DPLL to operate on
+ *
+ * Enable DPLL automatic idle control. This automatic idle mode
+ * switching takes effect only when the DPLL is locked, at least on
+ * OMAP3430. The DPLL will enter low-power stop when its downstream
+ * clocks are gated. No return value.
+ */
+static void omap3_dpll_allow_idle(struct clk *clk)
+{
+ const struct dpll_data *dd;
+
+ if (!clk || !clk->dpll_data)
+ return;
+
+ dd = clk->dpll_data;
+
+ /*
+ * REVISIT: CORE DPLL can optionally enter low-power bypass
+ * by writing 0x5 instead of 0x1. Add some mechanism to
+ * optionally enter this mode.
+ */
+ cm_rmw_reg_bits(dd->autoidle_mask,
+ DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask),
+ dd->autoidle_reg);
+}
+
+/**
+ * omap3_dpll_deny_idle - prevent DPLL from automatically idling
+ * @clk: struct clk * of the DPLL to operate on
+ *
+ * Disable DPLL automatic idle control. No return value.
+ */
+static void omap3_dpll_deny_idle(struct clk *clk)
+{
+ const struct dpll_data *dd;
+
+ if (!clk || !clk->dpll_data)
+ return;
+
+ dd = clk->dpll_data;
+
+ cm_rmw_reg_bits(dd->autoidle_mask,
+ DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask),
+ dd->autoidle_reg);
+}
+
+/* Clock control for DPLL outputs */
+
+/**
+ * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
+ * @clk: DPLL output struct clk
+ *
+ * Using parent clock DPLL data, look up DPLL state. If locked, set our
+ * rate to the dpll_clk * 2; otherwise, just use dpll_clk.
+ */
+static void omap3_clkoutx2_recalc(struct clk *clk)
+{
+ const struct dpll_data *dd;
+ u32 v;
+ struct clk *pclk;
+
+ /* Walk up the parents of clk, looking for a DPLL */
+ pclk = clk->parent;
+ while (pclk && !pclk->dpll_data)
+ pclk = pclk->parent;
+
+ /* clk does not have a DPLL as a parent? */
+ WARN_ON(!pclk);
+
+ dd = pclk->dpll_data;
+
+ WARN_ON(!dd->control_reg || !dd->enable_mask);
+
+ v = __raw_readl(dd->control_reg) & dd->enable_mask;
+ v >>= __ffs(dd->enable_mask);
+ if (v != DPLL_LOCKED)
+ clk->rate = clk->parent->rate;
+ else
+ clk->rate = clk->parent->rate * 2;
+
+ if (clk->flags & RATE_PROPAGATES)
+ propagate_rate(clk);
+}
+
+/* Common clock code */
+
+/*
+ * As it is structured now, this will prevent an OMAP2/3 multiboot
+ * kernel from compiling. This will need further attention.
+ */
+#if defined(CONFIG_ARCH_OMAP3)
+
+static struct clk_functions omap2_clk_functions = {
+ .clk_enable = omap2_clk_enable,
+ .clk_disable = omap2_clk_disable,
+ .clk_round_rate = omap2_clk_round_rate,
+ .clk_set_rate = omap2_clk_set_rate,
+ .clk_set_parent = omap2_clk_set_parent,
+ .clk_disable_unused = omap2_clk_disable_unused,
+};
+
+/*
+ * Set clocks for bypass mode for reboot to work.
+ */
+void omap2_clk_prepare_for_reboot(void)
+{
+ /* REVISIT: Not ready for 343x */
+#if 0
+ u32 rate;
+
+ if (vclk == NULL || sclk == NULL)
+ return;
+
+ rate = clk_get_rate(sclk);
+ clk_set_rate(vclk, rate);
+#endif
+}
+
+/* REVISIT: Move this init stuff out into clock.c */
+
+/*
+ * Switch the MPU rate if specified on cmdline.
+ * We cannot do this early until cmdline is parsed.
+ */
+static int __init omap2_clk_arch_init(void)
+{
+ if (!mpurate)
+ return -EINVAL;
+
+ /* REVISIT: not yet ready for 343x */
+#if 0
+ if (omap2_select_table_rate(&virt_prcm_set, mpurate))
+ printk(KERN_ERR "Could not find matching MPU rate\n");
+#endif
+
+ recalculate_root_clocks();
+
+ printk(KERN_INFO "Switched to new clocking rate (Crystal/DPLL3/MPU): "
+ "%ld.%01ld/%ld/%ld MHz\n",
+ (osc_sys_ck.rate / 1000000), (osc_sys_ck.rate / 100000) % 10,
+ (core_ck.rate / 1000000), (dpll1_fck.rate / 1000000)) ;
+
+ return 0;
+}
+arch_initcall(omap2_clk_arch_init);
+
+int __init omap2_clk_init(void)
+{
+ /* struct prcm_config *prcm; */
+ struct clk **clkp;
+ /* u32 clkrate; */
+ u32 cpu_clkflg;
+
+ /* REVISIT: Ultimately this will be used for multiboot */
+#if 0
+ if (cpu_is_omap242x()) {
+ cpu_mask = RATE_IN_242X;
+ cpu_clkflg = CLOCK_IN_OMAP242X;
+ clkp = onchip_24xx_clks;
+ } else if (cpu_is_omap2430()) {
+ cpu_mask = RATE_IN_243X;
+ cpu_clkflg = CLOCK_IN_OMAP243X;
+ clkp = onchip_24xx_clks;
+ }
+#endif
+ if (cpu_is_omap34xx()) {
+ cpu_mask = RATE_IN_343X;
+ cpu_clkflg = CLOCK_IN_OMAP343X;
+ clkp = onchip_34xx_clks;
+
+ /*
+ * Update this if there are further clock changes between ES2
+ * and production parts
+ */
+ if (is_sil_rev_equal_to(OMAP3430_REV_ES1_0)) {
+ /* No 3430ES1-only rates exist, so no RATE_IN_3430ES1 */
+ cpu_clkflg |= CLOCK_IN_OMAP3430ES1;
+ } else {
+ cpu_mask |= RATE_IN_3430ES2;
+ cpu_clkflg |= CLOCK_IN_OMAP3430ES2;
+ }
+ }
+
+ clk_init(&omap2_clk_functions);
+
+ for (clkp = onchip_34xx_clks;
+ clkp < onchip_34xx_clks + ARRAY_SIZE(onchip_34xx_clks);
+ clkp++) {
+ if ((*clkp)->flags & cpu_clkflg)
+ clk_register(*clkp);
+ }
+
+ /* REVISIT: Not yet ready for OMAP3 */
+#if 0
+ /* Check the MPU rate set by bootloader */
+ clkrate = omap2_get_dpll_rate_24xx(&dpll_ck);
+ for (prcm = rate_table; prcm->mpu_speed; prcm++) {
+ if (!(prcm->flags & cpu_mask))
+ continue;
+ if (prcm->xtal_speed != sys_ck.rate)
+ continue;
+ if (prcm->dpll_speed <= clkrate)
+ break;
+ }
+ curr_prcm_set = prcm;
+#endif
+
+ recalculate_root_clocks();
+
+ printk(KERN_INFO "Clocking rate (Crystal/DPLL/ARM core): "
+ "%ld.%01ld/%ld/%ld MHz\n",
+ (osc_sys_ck.rate / 1000000), (osc_sys_ck.rate / 100000) % 10,
+ (core_ck.rate / 1000000), (arm_fck.rate / 1000000));
+
+ /*
+ * Only enable those clocks we will need, let the drivers
+ * enable other clocks as necessary
+ */
+ clk_enable_init_clocks();
+
+ /* Avoid sleeping during omap2_clk_prepare_for_reboot() */
+ /* REVISIT: not yet ready for 343x */
+#if 0
+ vclk = clk_get(NULL, "virt_prcm_set");
+ sclk = clk_get(NULL, "sys_ck");
+#endif
+ return 0;
+}
+
+#endif