/*
* OMAP3-specific clock framework functions
*
- * Copyright (C) 2007 Texas Instruments, Inc.
- * Copyright (C) 2007 Nokia Corporation
+ * 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
#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 "cm.h"
#include "cm-regbits-34xx.h"
-/* CM_CLKEN_PLL*.EN* bit values */
-#define DPLL_LOCKED 0x7
+/* 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
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
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.
git.openpandora.org / pandora-kernel.git / blobdiff