/**
 * omap3_noncore_dpll_set_rate - set non-core DPLL rate
 * @clk: struct clk * of DPLL to set
 * @rate: rounded target rate
 *
 * Set the DPLL CLKOUT to the target rate.  If the DPLL can enter
 * low-power bypass, and the target rate is the bypass source clock
 * rate, then configure the DPLL for bypass.  Otherwise, round the
 * target rate if it hasn't been done already, then program and lock
 * the DPLL.  Returns -EINVAL upon error, or 0 upon success.
 */
int omap3_noncore_dpll_set_rate(struct clk_hw *hw, unsigned long rate,
					unsigned long parent_rate)
{
	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
	struct clk *new_parent = NULL;
	unsigned long rrate;
	u16 freqsel = 0;
	struct dpll_data *dd;
	int ret;

	if (!hw || !rate)
		return -EINVAL;

	dd = clk->dpll_data;
	if (!dd)
		return -EINVAL;

	if (__clk_get_rate(dd->clk_bypass) == rate &&
	    (dd->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
		pr_debug("%s: %s: set rate: entering bypass.\n",
			 __func__, __clk_get_name(hw->clk));

		__clk_prepare(dd->clk_bypass);
		clk_enable(dd->clk_bypass);
		ret = _omap3_noncore_dpll_bypass(clk);
		if (!ret)
			new_parent = dd->clk_bypass;
		clk_disable(dd->clk_bypass);
		__clk_unprepare(dd->clk_bypass);
	} else {
		__clk_prepare(dd->clk_ref);
		clk_enable(dd->clk_ref);

		if (dd->last_rounded_rate != rate) {
			rrate = __clk_round_rate(hw->clk, rate);
			if (rrate != rate) {
				pr_warn("%s: %s: final rate %lu does not match desired rate %lu\n",
					__func__, __clk_get_name(hw->clk),
					rrate, rate);
				rate = rrate;
			}
		}

		if (dd->last_rounded_rate == 0)
			return -EINVAL;

		/* Freqsel is available only on OMAP343X devices */
		if (cpu_is_omap343x()) {
			freqsel = _omap3_dpll_compute_freqsel(clk,
						dd->last_rounded_n);
			WARN_ON(!freqsel);
		}

		pr_debug("%s: %s: set rate: locking rate to %lu.\n",
			 __func__, __clk_get_name(hw->clk), rate);

		ret = omap3_noncore_dpll_program(clk, freqsel);
		if (!ret)
			new_parent = dd->clk_ref;
		clk_disable(dd->clk_ref);
		__clk_unprepare(dd->clk_ref);
	}
	/*
	* FIXME - this is all wrong.  common code handles reparenting and
	* migrating prepare/enable counts.  dplls should be a multiplexer
	* clock and this should be a set_parent operation so that all of that
	* stuff is inherited for free
	*/

	if (!ret && clk_get_parent(hw->clk) != new_parent)
		__clk_reparent(hw->clk, new_parent);

	return 0;
}
Beispiel #2
0
/**
 * omap3_noncore_dpll_set_rate - set non-core DPLL rate
 * @clk: struct clk * of DPLL to set
 * @rate: rounded target rate
 *
 * Set the DPLL CLKOUT to the target rate.  If the DPLL can enter
 * low-power bypass, and the target rate is the bypass source clock
 * rate, then configure the DPLL for bypass.  Otherwise, round the
 * target rate if it hasn't been done already, then program and lock
 * the DPLL.  Returns -EINVAL upon error, or 0 upon success.
 */
int omap3_noncore_dpll_set_rate(struct clk_hw *hw, unsigned long rate,
					unsigned long parent_rate)
{
	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
	struct clk *new_parent = NULL;
	u16 freqsel = 0;
	struct dpll_data *dd;
	int ret;

	if (!hw || !rate)
		return -EINVAL;

	dd = clk->dpll_data;
	if (!dd)
		return -EINVAL;

	__clk_prepare(dd->clk_bypass);
	clk_enable(dd->clk_bypass);
	__clk_prepare(dd->clk_ref);
	clk_enable(dd->clk_ref);

	if (__clk_get_rate(dd->clk_bypass) == rate &&
	    (dd->modes & (1 << DPLL_LOW_POWER_BYPASS))) {
		pr_debug("%s: %s: set rate: entering bypass.\n",
			 __func__, __clk_get_name(hw->clk));

		ret = _omap3_noncore_dpll_bypass(clk);
		if (!ret)
			new_parent = dd->clk_bypass;
	} else {
		if (dd->last_rounded_rate != rate)
			rate = __clk_round_rate(hw->clk, rate);

		if (dd->last_rounded_rate == 0)
			return -EINVAL;

		/* No freqsel on OMAP4 and OMAP3630 */
		if (!cpu_is_omap44xx() && !cpu_is_omap3630()) {
			freqsel = _omap3_dpll_compute_freqsel(clk,
						dd->last_rounded_n);
			if (!freqsel)
				WARN_ON(1);
		}

		pr_debug("%s: %s: set rate: locking rate to %lu.\n",
			 __func__, __clk_get_name(hw->clk), rate);

		ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m,
						dd->last_rounded_n, freqsel);
		if (!ret)
			new_parent = dd->clk_ref;
	}
	/*
	* FIXME - this is all wrong.  common code handles reparenting and
	* migrating prepare/enable counts.  dplls should be a multiplexer
	* clock and this should be a set_parent operation so that all of that
	* stuff is inherited for free
	*/

	if (!ret)
		__clk_reparent(hw->clk, new_parent);

	clk_disable(dd->clk_ref);
	__clk_unprepare(dd->clk_ref);
	clk_disable(dd->clk_bypass);
	__clk_unprepare(dd->clk_bypass);

	return 0;
}