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Commit 45b06682 authored by Matthias Wieloch's avatar Matthias Wieloch Committed by Stephen Boyd
Browse files

clk: at91: fix programmable clock for sama5d2 



The prescaler formula of the programmable clock has changed for sama5d2.
Update the driver accordingly.

Fixes: a2038077 ("clk: at91: add sama5d2 PMC driver")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@microchip.com>
[nicolas.ferre@microchip.com: adapt the prescaler range,
		fix clk_programmable_recalc_rate, split patch]
Signed-off-by: default avatarMatthias Wieloch <matthias.wieloch@few-bauer.de>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent 9e98c678

drivers/clk/at91/clk-programmable.c

+43 −14
Original line number Diff line number Diff line
@@ -20,8 +20,7 @@ 
#define PROG_ID_MAX		7



#define PROG_STATUS_MASK(id)	(1 << ((id) + 8))

#define PROG_PRES_MASK		0x7

#define PROG_PRES(layout, pckr)	((pckr >> layout->pres_shift) & PROG_PRES_MASK)

#define PROG_PRES(layout, pckr)	((pckr >> layout->pres_shift) & layout->pres_mask)

#define PROG_MAX_RM9200_CSS	3



struct clk_programmable {
@@ -37,20 +36,29 @@ static unsigned long clk_programmable_recalc_rate(struct clk_hw *hw, 
						  unsigned long parent_rate)

{

	struct clk_programmable *prog = to_clk_programmable(hw);

	const struct clk_programmable_layout *layout = prog->layout;

	unsigned int pckr;

	unsigned long rate;



	regmap_read(prog->regmap, AT91_PMC_PCKR(prog->id), &pckr);



	return parent_rate >> PROG_PRES(prog->layout, pckr);

	if (layout->is_pres_direct)

		rate = parent_rate / (PROG_PRES(layout, pckr) + 1);

	else

		rate = parent_rate >> PROG_PRES(layout, pckr);



	return rate;

}



static int clk_programmable_determine_rate(struct clk_hw *hw,

					   struct clk_rate_request *req)

{

	struct clk_programmable *prog = to_clk_programmable(hw);

	const struct clk_programmable_layout *layout = prog->layout;

	struct clk_hw *parent;

	long best_rate = -EINVAL;

	unsigned long parent_rate;

	unsigned long tmp_rate;

	unsigned long tmp_rate = 0;

	int shift;

	int i;
@@ -60,11 +68,19 @@ static int clk_programmable_determine_rate(struct clk_hw *hw, 
			continue;



		parent_rate = clk_hw_get_rate(parent);

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

		if (layout->is_pres_direct) {

			for (shift = 0; shift <= layout->pres_mask; shift++) {

				tmp_rate = parent_rate / (shift + 1);

				if (tmp_rate <= req->rate)

					break;

			}

		} else {

			for (shift = 0; shift < layout->pres_mask; shift++) {

				tmp_rate = parent_rate >> shift;

				if (tmp_rate <= req->rate)

					break;

			}

		}



		if (tmp_rate > req->rate)

			continue;
@@ -137,16 +153,23 @@ static int clk_programmable_set_rate(struct clk_hw *hw, unsigned long rate, 
	if (!div)

		return -EINVAL;



	if (layout->is_pres_direct) {

		shift = div - 1;



		if (shift > layout->pres_mask)

			return -EINVAL;

	} else {

		shift = fls(div) - 1;



		if (div != (1 << shift))

			return -EINVAL;



	if (shift >= PROG_PRES_MASK)

		if (shift >= layout->pres_mask)

			return -EINVAL;

	}



	regmap_update_bits(prog->regmap, AT91_PMC_PCKR(prog->id),

			   PROG_PRES_MASK << layout->pres_shift,

			   layout->pres_mask << layout->pres_shift,

			   shift << layout->pres_shift);



	return 0;
@@ -202,19 +225,25 @@ at91_clk_register_programmable(struct regmap *regmap, 
}



const struct clk_programmable_layout at91rm9200_programmable_layout = {

	.pres_mask = 0x7,

	.pres_shift = 2,

	.css_mask = 0x3,

	.have_slck_mck = 0,

	.is_pres_direct = 0,

};



const struct clk_programmable_layout at91sam9g45_programmable_layout = {

	.pres_mask = 0x7,

	.pres_shift = 2,

	.css_mask = 0x3,

	.have_slck_mck = 1,

	.is_pres_direct = 0,

};



const struct clk_programmable_layout at91sam9x5_programmable_layout = {

	.pres_mask = 0x7,

	.pres_shift = 4,

	.css_mask = 0x7,

	.have_slck_mck = 0,

	.is_pres_direct = 0,

};

drivers/clk/at91/pmc.h

+2 −0
Original line number Diff line number Diff line
@@ -71,9 +71,11 @@ struct clk_pll_characteristics { 
};



struct clk_programmable_layout {

	u8 pres_mask;

	u8 pres_shift;

	u8 css_mask;

	u8 have_slck_mck;

	u8 is_pres_direct;

};



extern const struct clk_programmable_layout at91rm9200_programmable_layout;

drivers/clk/at91/sama5d2.c

+9 −1
Original line number Diff line number Diff line
@@ -125,6 +125,14 @@ static const struct { 
	  .pll = true },

};



static const struct clk_programmable_layout sama5d2_programmable_layout = {

	.pres_mask = 0xff,

	.pres_shift = 4,

	.css_mask = 0x7,

	.have_slck_mck = 0,

	.is_pres_direct = 1,

};



static void __init sama5d2_pmc_setup(struct device_node *np)

{

	struct clk_range range = CLK_RANGE(0, 0);
@@ -249,7 +257,7 @@ static void __init sama5d2_pmc_setup(struct device_node *np) 


		hw = at91_clk_register_programmable(regmap, name,

						    parent_names, 6, i,

						    &at91sam9x5_programmable_layout);

						    &sama5d2_programmable_layout);

		if (IS_ERR(hw))

			goto err_free;

	}