Messages in this thread | | | Date | Tue, 4 Aug 2020 18:00:28 +0200 | From | Alexandre Belloni <> | Subject | Re: [PATCH] clk: at91: clk-main: update key before writing AT91_CKGR_MOR |
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On 30/07/2020 12:03:23+0300, Claudiu Beznea wrote: > SAMA5D2 datasheet specifies on chapter 33.22.8 (PMC Clock Generator > Main Oscillator Register) that writing any value other than > 0x37 on KEY field aborts the write operation. Use the key when > selecting main clock parent. > > Fixes: 27cb1c2083373 ("clk: at91: rework main clk implementation") > Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
> --- > drivers/clk/at91/clk-main.c | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/clk/at91/clk-main.c b/drivers/clk/at91/clk-main.c > index 5c83e899084f..cfae2f59df66 100644 > --- a/drivers/clk/at91/clk-main.c > +++ b/drivers/clk/at91/clk-main.c > @@ -437,12 +437,17 @@ static int clk_sam9x5_main_set_parent(struct clk_hw *hw, u8 index) > return -EINVAL; > > regmap_read(regmap, AT91_CKGR_MOR, &tmp); > - tmp &= ~MOR_KEY_MASK; > > if (index && !(tmp & AT91_PMC_MOSCSEL)) > - regmap_write(regmap, AT91_CKGR_MOR, tmp | AT91_PMC_MOSCSEL); > + tmp = AT91_PMC_MOSCSEL; > else if (!index && (tmp & AT91_PMC_MOSCSEL)) > - regmap_write(regmap, AT91_CKGR_MOR, tmp & ~AT91_PMC_MOSCSEL); > + tmp = 0; > + else > + return 0; > + > + regmap_update_bits(regmap, AT91_CKGR_MOR, > + AT91_PMC_MOSCSEL | MOR_KEY_MASK, > + tmp | AT91_PMC_KEY); > > while (!clk_sam9x5_main_ready(regmap)) > cpu_relax(); > -- > 2.7.4 >
-- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
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