diff mbox

[v5,01/20] clk: bcm2835: pll_off should only set CM_PLL_ANARST

Message ID 1456673831-2408-2-git-send-email-kernel@martin.sperl.org (mailing list archive)
State New, archived
Headers show

Commit Message

Martin Sperl Feb. 28, 2016, 3:36 p.m. UTC
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.

Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
---
 drivers/clk/bcm/clk-bcm2835.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Comments

Stefan Wahren Feb. 28, 2016, 5:58 p.m. UTC | #1
Hi Martin,

> kernel@martin.sperl.org hat am 28. Februar 2016 um 16:36 geschrieben:
>
>
> 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.
>
> Signed-off-by: Martin Sperl <kernel@martin.sperl.org>

Fixes: 41691b8862e2 ("clk: bcm2835: Add support for programming the audio domain
clocks")

> ---
> drivers/clk/bcm/clk-bcm2835.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
> index 5747a9d..d3009a6 100644
> --- a/drivers/clk/bcm/clk-bcm2835.c
> +++ b/drivers/clk/bcm/clk-bcm2835.c
> @@ -913,8 +913,12 @@ 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);
> + 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);

Since this change adds a RMW cycle we should add the spinlocks for
bcm2835_pll_off here and not in 03/20.

Regards
Stefan
diff mbox

Patch

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 5747a9d..d3009a6 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -913,8 +913,12 @@  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);
+	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);
 }
 
 static int bcm2835_pll_on(struct clk_hw *hw)