clk: bcm2835: add locking to pll*_on/off methods
Add missing locking to:
* bcm2835_pll_divider_on
* bcm2835_pll_divider_off
to protect the read modify write cycle for the
register access protecting both cm_reg and a2w_reg
registers.
Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the
audio domain clocks")
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index adbaa55..a39f8a7 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1085,10 +1085,12 @@
struct bcm2835_cprman *cprman = divider->cprman;
const struct bcm2835_pll_divider_data *data = divider->data;
+ spin_lock(&cprman->regs_lock);
cprman_write(cprman, data->cm_reg,
(cprman_read(cprman, data->cm_reg) &
~data->load_mask) | data->hold_mask);
cprman_write(cprman, data->a2w_reg, A2W_PLL_CHANNEL_DISABLE);
+ spin_unlock(&cprman->regs_lock);
}
static int bcm2835_pll_divider_on(struct clk_hw *hw)
@@ -1097,12 +1099,14 @@
struct bcm2835_cprman *cprman = divider->cprman;
const struct bcm2835_pll_divider_data *data = divider->data;
+ spin_lock(&cprman->regs_lock);
cprman_write(cprman, data->a2w_reg,
cprman_read(cprman, data->a2w_reg) &
~A2W_PLL_CHANNEL_DISABLE);
cprman_write(cprman, data->cm_reg,
cprman_read(cprman, data->cm_reg) & ~data->hold_mask);
+ spin_unlock(&cprman->regs_lock);
return 0;
}