Commit b4c115c7 authored by Claudiu Beznea's avatar Claudiu Beznea Committed by Stephen Boyd
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clk: at91: clk-peripheral: add support for changeable parent rate 



Some peripheral clocks on SAMA7G5 supports requesting parent to change
its rate (image related clocks: csi, csi2dc, isc). Add support
so that if registered with this option the clock rate to be
requested from parent.

Signed-off-by: default avatarClaudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/1595403506-8209-14-git-send-email-claudiu.beznea@microchip.com


Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent 75c88143

drivers/clk/at91/at91sam9n12.c

+1 −1
Original line number Diff line number Diff line
@@ -222,7 +222,7 @@ static void __init at91sam9n12_pmc_setup(struct device_node *np) 
							 at91sam9n12_periphck[i].n,

							 "masterck",

							 at91sam9n12_periphck[i].id,

							 &range);

							 &range, INT_MIN);

		if (IS_ERR(hw))

			goto err_free;

drivers/clk/at91/at91sam9x5.c

+2 −2
Original line number Diff line number Diff line
@@ -257,7 +257,7 @@ static void __init at91sam9x5_pmc_setup(struct device_node *np, 
							 at91sam9x5_periphck[i].n,

							 "masterck",

							 at91sam9x5_periphck[i].id,

							 &range);

							 &range, INT_MIN);

		if (IS_ERR(hw))

			goto err_free;
@@ -270,7 +270,7 @@ static void __init at91sam9x5_pmc_setup(struct device_node *np, 
							 extra_pcks[i].n,

							 "masterck",

							 extra_pcks[i].id,

							 &range);

							 &range, INT_MIN);

		if (IS_ERR(hw))

			goto err_free;

drivers/clk/at91/clk-peripheral.c

+104 −5
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ struct clk_sam9x5_peripheral { 
	u32 div;

	const struct clk_pcr_layout *layout;

	bool auto_div;

	int chg_pid;

};



#define to_clk_sam9x5_peripheral(hw) \
@@ -238,6 +239,87 @@ clk_sam9x5_peripheral_recalc_rate(struct clk_hw *hw, 
	return parent_rate >> periph->div;

}



static void clk_sam9x5_peripheral_best_diff(struct clk_rate_request *req,

					    struct clk_hw *parent,

					    unsigned long parent_rate,

					    u32 shift, long *best_diff,

					    long *best_rate)

{

	unsigned long tmp_rate = parent_rate >> shift;

	unsigned long tmp_diff = abs(req->rate - tmp_rate);



	if (*best_diff < 0 || *best_diff >= tmp_diff) {

		*best_rate = tmp_rate;

		*best_diff = tmp_diff;

		req->best_parent_rate = parent_rate;

		req->best_parent_hw = parent;

	}

}



static int clk_sam9x5_peripheral_determine_rate(struct clk_hw *hw,

						struct clk_rate_request *req)

{

	struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw);

	struct clk_hw *parent = clk_hw_get_parent(hw);

	struct clk_rate_request req_parent = *req;

	unsigned long parent_rate = clk_hw_get_rate(parent);

	unsigned long tmp_rate;

	long best_rate = LONG_MIN;

	long best_diff = LONG_MIN;

	u32 shift;



	if (periph->id < PERIPHERAL_ID_MIN || !periph->range.max)

		return parent_rate;



	/* Fist step: check the available dividers. */

	for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) {

		tmp_rate = parent_rate >> shift;



		if (periph->range.max && tmp_rate > periph->range.max)

			continue;



		clk_sam9x5_peripheral_best_diff(req, parent, parent_rate,

						shift, &best_diff, &best_rate);



		if (!best_diff || best_rate <= req->rate)

			break;

	}



	if (periph->chg_pid < 0)

		goto end;



	/* Step two: try to request rate from parent. */

	parent = clk_hw_get_parent_by_index(hw, periph->chg_pid);

	if (!parent)

		goto end;



	for (shift = 0; shift <= PERIPHERAL_MAX_SHIFT; shift++) {

		req_parent.rate = req->rate << shift;



		if (__clk_determine_rate(parent, &req_parent))

			continue;



		clk_sam9x5_peripheral_best_diff(req, parent, req_parent.rate,

						shift, &best_diff, &best_rate);



		if (!best_diff)

			break;

	}

end:

	if (best_rate < 0 ||

	    (periph->range.max && best_rate > periph->range.max))

		return -EINVAL;



	pr_debug("PCK: %s, best_rate = %ld, parent clk: %s @ %ld\n",

		 __func__, best_rate,

		 __clk_get_name((req->best_parent_hw)->clk),

		 req->best_parent_rate);



	req->rate = best_rate;



	return 0;

}



static long clk_sam9x5_peripheral_round_rate(struct clk_hw *hw,

					     unsigned long rate,

					     unsigned long *parent_rate)
@@ -320,11 +402,21 @@ static const struct clk_ops sam9x5_peripheral_ops = { 
	.set_rate = clk_sam9x5_peripheral_set_rate,

};



static const struct clk_ops sam9x5_peripheral_chg_ops = {

	.enable = clk_sam9x5_peripheral_enable,

	.disable = clk_sam9x5_peripheral_disable,

	.is_enabled = clk_sam9x5_peripheral_is_enabled,

	.recalc_rate = clk_sam9x5_peripheral_recalc_rate,

	.determine_rate = clk_sam9x5_peripheral_determine_rate,

	.set_rate = clk_sam9x5_peripheral_set_rate,

};



struct clk_hw * __init

at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock,

				    const struct clk_pcr_layout *layout,

				    const char *name, const char *parent_name,

				    u32 id, const struct clk_range *range)

				    u32 id, const struct clk_range *range,

				    int chg_pid)

{

	struct clk_sam9x5_peripheral *periph;

	struct clk_init_data init;
@@ -339,10 +431,16 @@ at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock, 
		return ERR_PTR(-ENOMEM);



	init.name = name;

	init.ops = &sam9x5_peripheral_ops;

	init.parent_names = (parent_name ? &parent_name : NULL);

	init.num_parents = (parent_name ? 1 : 0);

	init.parent_names = &parent_name;

	init.num_parents = 1;

	if (chg_pid < 0) {

		init.flags = 0;

		init.ops = &sam9x5_peripheral_ops;

	} else {

		init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE |

			     CLK_SET_RATE_PARENT;

		init.ops = &sam9x5_peripheral_chg_ops;

	}



	periph->id = id;

	periph->hw.init = &init;
@@ -353,6 +451,7 @@ at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock, 
		periph->auto_div = true;

	periph->layout = layout;

	periph->range = *range;

	periph->chg_pid = chg_pid;



	hw = &periph->hw;

	ret = clk_hw_register(NULL, &periph->hw);

drivers/clk/at91/dt-compat.c

+2 −1
Original line number Diff line number Diff line
@@ -463,7 +463,8 @@ of_at91_clk_periph_setup(struct device_node *np, u8 type) 
								 &dt_pcr_layout,

								 name,

								 parent_name,

								 id, &range);

								 id, &range,

								 INT_MIN);

		}



		if (IS_ERR(hw))

drivers/clk/at91/pmc.h

+2 −1
Original line number Diff line number Diff line
@@ -168,7 +168,8 @@ struct clk_hw * __init 
at91_clk_register_sam9x5_peripheral(struct regmap *regmap, spinlock_t *lock,

				    const struct clk_pcr_layout *layout,

				    const char *name, const char *parent_name,

				    u32 id, const struct clk_range *range);

				    u32 id, const struct clk_range *range,

				    int chg_pid);



struct clk_hw * __init

at91_clk_register_pll(struct regmap *regmap, const char *name,

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