clk: bcm2835: add locking to pll*_on/off methods

commit ec36a5c6682fdd5328abf15c3c67281bed0241d7 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 4f9830c1b121f76c60a95203eb4ea906999b97f3..185a4d859638c79455ca87464bd458c745285f7d 100644 (file)
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -1068,10 +1068,12 @@ static void bcm2835_pll_divider_off(struct clk_hw *hw)
        struct bcm2835_cprman *cprman = divider->cprman;
        const struct bcm2835_pll_divider_data *data = divider->data;
 
        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);
        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)
 }
 
 static int bcm2835_pll_divider_on(struct clk_hw *hw)


@@ -1080,12 +1082,14 @@ static int bcm2835_pll_divider_on(struct clk_hw *hw)
        struct bcm2835_cprman *cprman = divider->cprman;
        const struct bcm2835_pll_divider_data *data = divider->data;
 
        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);
        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;
 }
 
        return 0;
 }