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authorClaudiu Beznea <claudiu.beznea@microchip.com>2020-08-25 09:59:10 +0300
committerStephen Boyd <sboyd@kernel.org>2020-10-14 05:59:01 +0300
commit85d071e7f19a6a9abf30476b90b3819642568756 (patch)
tree5a24c02bd18829f39e874fdce1c46518db2a76b3 /drivers/clk
parenteddfb2e1eed6440db9ee36cc4d2a0abeeabeb942 (diff)
downloadlinux-85d071e7f19a6a9abf30476b90b3819642568756.tar.xz
clk: at91: clk-main: update key before writing AT91_CKGR_MOR
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> Link: https://lore.kernel.org/r/1598338751-20607-3-git-send-email-claudiu.beznea@microchip.com Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/at91/clk-main.c11
1 files 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();