* linux/arch/arm/mach-omap2/clock.c
*
* Copyright (C) 2005-2008 Texas Instruments, Inc.
- * Copyright (C) 2004-2008 Nokia Corporation
+ * Copyright (C) 2004-2010 Nokia Corporation
*
* Contacts:
* Richard Woodruff <r-woodruff2@ti.com>
*/
#undef DEBUG
-#include <linux/module.h>
#include <linux/kernel.h>
-#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
+#include <linux/err.h>
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/io.h>
u8 cpu_mask;
-/*-------------------------------------------------------------------------
- * OMAP2/3/4 specific clock functions
- *-------------------------------------------------------------------------*/
+/*
+ * OMAP2+ specific clock functions
+ */
/* Private functions */
clk->name);
}
-/* Enables clock without considering parent dependencies or use count
- * REVISIT: Maybe change this to use clk->enable like on omap1?
- */
-static int _omap2_clk_enable(struct clk *clk)
-{
- return clk->ops->enable(clk);
-}
-
-/* Disables clock without considering parent dependencies or use count */
-static void _omap2_clk_disable(struct clk *clk)
-{
- clk->ops->disable(clk);
-}
-
/* Public functions */
-/**
- * omap2xxx_clk_commit - commit clock parent/rate changes in hardware
- * @clk: struct clk *
- *
- * If @clk has the DELAYED_APP flag set, meaning that parent/rate changes
- * don't take effect until the VALID_CONFIG bit is written, write the
- * VALID_CONFIG bit and wait for the write to complete. No return value.
- */
-void omap2xxx_clk_commit(struct clk *clk)
-{
- if (!cpu_is_omap24xx())
- return;
-
- if (!(clk->flags & DELAYED_APP))
- return;
-
- prm_write_mod_reg(OMAP24XX_VALID_CONFIG, OMAP24XX_GR_MOD,
- OMAP2_PRCM_CLKCFG_CTRL_OFFSET);
- /* OCP barrier */
- prm_read_mod_reg(OMAP24XX_GR_MOD, OMAP2_PRCM_CLKCFG_CTRL_OFFSET);
-}
-
/**
* omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
* @clk: OMAP clock struct ptr to use
.disable = omap2_dflt_clk_disable,
};
+/**
+ * omap2_clk_disable - disable a clock, if the system is not using it
+ * @clk: struct clk * to disable
+ *
+ * Decrements the usecount on struct clk @clk. If there are no users
+ * left, call the clkops-specific clock disable function to disable it
+ * in hardware. If the clock is part of a clockdomain (which they all
+ * should be), request that the clockdomain be disabled. (It too has
+ * a usecount, and so will not be disabled in the hardware until it no
+ * longer has any users.) If the clock has a parent clock (most of
+ * them do), then call ourselves, recursing on the parent clock. This
+ * can cause an entire branch of the clock tree to be powered off by
+ * simply disabling one clock. Intended to be called with the clockfw_lock
+ * spinlock held. No return value.
+ */
void omap2_clk_disable(struct clk *clk)
{
- if (clk->usecount > 0 && !(--clk->usecount)) {
- _omap2_clk_disable(clk);
- if (clk->parent)
- omap2_clk_disable(clk->parent);
- if (clk->clkdm)
- omap2_clkdm_clk_disable(clk->clkdm, clk);
-
+ if (clk->usecount == 0) {
+ WARN(1, "clock: %s: omap2_clk_disable() called, but usecount "
+ "already 0?", clk->name);
+ return;
}
+
+ pr_debug("clock: %s: decrementing usecount\n", clk->name);
+
+ clk->usecount--;
+
+ if (clk->usecount > 0)
+ return;
+
+ pr_debug("clock: %s: disabling in hardware\n", clk->name);
+
+ clk->ops->disable(clk);
+
+ if (clk->clkdm)
+ omap2_clkdm_clk_disable(clk->clkdm, clk);
+
+ if (clk->parent)
+ omap2_clk_disable(clk->parent);
}
+/**
+ * omap2_clk_enable - request that the system enable a clock
+ * @clk: struct clk * to enable
+ *
+ * Increments the usecount on struct clk @clk. If there were no users
+ * previously, then recurse up the clock tree, enabling all of the
+ * clock's parents and all of the parent clockdomains, and finally,
+ * enabling @clk's clockdomain, and @clk itself. Intended to be
+ * called with the clockfw_lock spinlock held. Returns 0 upon success
+ * or a negative error code upon failure.
+ */
int omap2_clk_enable(struct clk *clk)
{
- int ret = 0;
+ int ret;
- if (clk->usecount++ == 0) {
- if (clk->clkdm)
- omap2_clkdm_clk_enable(clk->clkdm, clk);
+ pr_debug("clock: %s: incrementing usecount\n", clk->name);
- if (clk->parent) {
- ret = omap2_clk_enable(clk->parent);
- if (ret)
- goto err;
- }
+ clk->usecount++;
- ret = _omap2_clk_enable(clk);
+ if (clk->usecount > 1)
+ return 0;
+
+ pr_debug("clock: %s: enabling in hardware\n", clk->name);
+
+ if (clk->parent) {
+ ret = omap2_clk_enable(clk->parent);
if (ret) {
- if (clk->parent)
- omap2_clk_disable(clk->parent);
+ WARN(1, "clock: %s: could not enable parent %s: %d\n",
+ clk->name, clk->parent->name, ret);
+ goto oce_err1;
+ }
+ }
- goto err;
+ if (clk->clkdm) {
+ ret = omap2_clkdm_clk_enable(clk->clkdm, clk);
+ if (ret) {
+ WARN(1, "clock: %s: could not enable clockdomain %s: "
+ "%d\n", clk->name, clk->clkdm->name, ret);
+ goto oce_err2;
}
}
- return ret;
-err:
+ ret = clk->ops->enable(clk);
+ if (ret) {
+ WARN(1, "clock: %s: could not enable: %d\n", clk->name, ret);
+ goto oce_err3;
+ }
+
+ return 0;
+
+oce_err3:
if (clk->clkdm)
omap2_clkdm_clk_disable(clk->clkdm, clk);
+oce_err2:
+ if (clk->parent)
+ omap2_clk_disable(clk->parent);
+oce_err1:
clk->usecount--;
+
return ret;
}
return omap2_clksel_set_parent(clk, new_parent);
}
-/*-------------------------------------------------------------------------
- * Omap2 clock reset and init functions
- *-------------------------------------------------------------------------*/
+/* OMAP3/4 non-CORE DPLL clkops */
+
+#if defined(CONFIG_ARCH_OMAP3) || defined(CONFIG_ARCH_OMAP4)
+
+const struct clkops clkops_omap3_noncore_dpll_ops = {
+ .enable = omap3_noncore_dpll_enable,
+ .disable = omap3_noncore_dpll_disable,
+};
+
+#endif
+
+
+/*
+ * OMAP2+ clock reset and init functions
+ */
#ifdef CONFIG_OMAP_RESET_CLOCKS
void omap2_clk_disable_unused(struct clk *clk)
if (cpu_is_omap34xx()) {
omap2_clk_enable(clk);
omap2_clk_disable(clk);
- } else
- _omap2_clk_disable(clk);
+ } else {
+ clk->ops->disable(clk);
+ }
if (clk->clkdm != NULL)
pwrdm_clkdm_state_switch(clk->clkdm);
}
#endif
+/**
+ * omap2_clk_switch_mpurate_at_boot - switch ARM MPU rate by boot-time argument
+ * @mpurate_ck_name: clk name of the clock to change rate
+ *
+ * Change the ARM MPU clock rate to the rate specified on the command
+ * line, if one was specified. @mpurate_ck_name should be
+ * "virt_prcm_set" on OMAP2xxx and "dpll1_ck" on OMAP34xx/OMAP36xx.
+ * XXX Does not handle voltage scaling - on OMAP2xxx this is currently
+ * handled by the virt_prcm_set clock, but this should be handled by
+ * the OPP layer. XXX This is intended to be handled by the OPP layer
+ * code in the near future and should be removed from the clock code.
+ * Returns -EINVAL if 'mpurate' is zero or if clk_set_rate() rejects
+ * the rate, -ENOENT if the struct clk referred to by @mpurate_ck_name
+ * cannot be found, or 0 upon success.
+ */
+int __init omap2_clk_switch_mpurate_at_boot(const char *mpurate_ck_name)
+{
+ struct clk *mpurate_ck;
+ int r;
+
+ if (!mpurate)
+ return -EINVAL;
+
+ mpurate_ck = clk_get(NULL, mpurate_ck_name);
+ if (WARN(IS_ERR(mpurate_ck), "Failed to get %s.\n", mpurate_ck_name))
+ return -ENOENT;
+
+ r = clk_set_rate(mpurate_ck, mpurate);
+ if (IS_ERR_VALUE(r)) {
+ WARN(1, "clock: %s: unable to set MPU rate to %d: %d\n",
+ mpurate_ck->name, mpurate, r);
+ return -EINVAL;
+ }
+
+ calibrate_delay();
+ recalculate_root_clocks();
+
+ clk_put(mpurate_ck);
+
+ return 0;
+}
+
+/**
+ * omap2_clk_print_new_rates - print summary of current clock tree rates
+ * @hfclkin_ck_name: clk name for the off-chip HF oscillator
+ * @core_ck_name: clk name for the on-chip CORE_CLK
+ * @mpu_ck_name: clk name for the ARM MPU clock
+ *
+ * Prints a short message to the console with the HFCLKIN oscillator
+ * rate, the rate of the CORE clock, and the rate of the ARM MPU clock.
+ * Called by the boot-time MPU rate switching code. XXX This is intended
+ * to be handled by the OPP layer code in the near future and should be
+ * removed from the clock code. No return value.
+ */
+void __init omap2_clk_print_new_rates(const char *hfclkin_ck_name,
+ const char *core_ck_name,
+ const char *mpu_ck_name)
+{
+ struct clk *hfclkin_ck, *core_ck, *mpu_ck;
+ unsigned long hfclkin_rate;
+
+ mpu_ck = clk_get(NULL, mpu_ck_name);
+ if (WARN(IS_ERR(mpu_ck), "clock: failed to get %s.\n", mpu_ck_name))
+ return;
+
+ core_ck = clk_get(NULL, core_ck_name);
+ if (WARN(IS_ERR(core_ck), "clock: failed to get %s.\n", core_ck_name))
+ return;
+
+ hfclkin_ck = clk_get(NULL, hfclkin_ck_name);
+ if (WARN(IS_ERR(hfclkin_ck), "Failed to get %s.\n", hfclkin_ck_name))
+ return;
+
+ hfclkin_rate = clk_get_rate(hfclkin_ck);
+
+ pr_info("Switched to new clocking rate (Crystal/Core/MPU): "
+ "%ld.%01ld/%ld/%ld MHz\n",
+ (hfclkin_rate / 1000000),
+ ((hfclkin_rate / 100000) % 10),
+ (clk_get_rate(core_ck) / 1000000),
+ (clk_get_rate(mpu_ck) / 1000000));
+}
+
/* Common data */
struct clk_functions omap2_clk_functions = {