| Message ID | 1596099803-1393-1-git-send-email-claudiu.beznea@microchip.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | clk: at91: clk-main: update key before writing AT91_CKGR_MOR | expand |
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 >
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();
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> --- drivers/clk/at91/clk-main.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)