| Message ID | 1456745963-2403-2-git-send-email-kernel@martin.sperl.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
kernel@martin.sperl.org writes: > From: Martin Sperl <kernel@martin.sperl.org> > > bcm2835_pll_off is currently assigning CM_PLL_ANARST > to the control register. > > This patch only sets the CM_PLL_ANARST bit > not resetting any of the other bits, which allows > restoring the register to its original value > via bcm2834_pll_on. > > It also now locks during the read/modify/write cycle of > both registers. > > Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the > audio domain clocks") > > Signed-off-by: Martin Sperl <kernel@martin.sperl.org> > --- > drivers/clk/bcm/clk-bcm2835.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c > index 5747a9d..2b7c6af 100644 > --- a/drivers/clk/bcm/clk-bcm2835.c > +++ b/drivers/clk/bcm/clk-bcm2835.c > @@ -913,8 +913,14 @@ static void bcm2835_pll_off(struct clk_hw *hw) > struct bcm2835_cprman *cprman = pll->cprman; > const struct bcm2835_pll_data *data = pll->data; > > - cprman_write(cprman, data->cm_ctrl_reg, CM_PLL_ANARST); > - cprman_write(cprman, data->a2w_ctrl_reg, A2W_PLL_CTRL_PWRDN); > + spin_lock(&cprman->regs_lock); > + cprman_write(cprman, data->cm_ctrl_reg, > + cprman_read(cprman, data->cm_ctrl_reg) | > + CM_PLL_ANARST); > + cprman_write(cprman, data->a2w_ctrl_reg, > + cprman_read(cprman, data->a2w_ctrl_reg) | > + A2W_PLL_CTRL_PWRDN); > + spin_unlock(&cprman->regs_lock); > } I think I see now: we're making sure that the hold_mask of a divider doesn't get lost if we turn its source PLL off. Reviewed-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c index 5747a9d..2b7c6af 100644 --- a/drivers/clk/bcm/clk-bcm2835.c +++ b/drivers/clk/bcm/clk-bcm2835.c @@ -913,8 +913,14 @@ static void bcm2835_pll_off(struct clk_hw *hw) struct bcm2835_cprman *cprman = pll->cprman; const struct bcm2835_pll_data *data = pll->data; - cprman_write(cprman, data->cm_ctrl_reg, CM_PLL_ANARST); - cprman_write(cprman, data->a2w_ctrl_reg, A2W_PLL_CTRL_PWRDN); + spin_lock(&cprman->regs_lock); + cprman_write(cprman, data->cm_ctrl_reg, + cprman_read(cprman, data->cm_ctrl_reg) | + CM_PLL_ANARST); + cprman_write(cprman, data->a2w_ctrl_reg, + cprman_read(cprman, data->a2w_ctrl_reg) | + A2W_PLL_CTRL_PWRDN); + spin_unlock(&cprman->regs_lock); } static int bcm2835_pll_on(struct clk_hw *hw)