[PATCH 4.6 065/121] clk: bcm2835: pll_off should only update CM_PLL_ANARST

Greg Kroah-Hartman
2016-06-05T22:00:14Z

From: Martin Sperl <kernel@martin.sperl.org>

commit 6727f086cfe4ddcc651eb2bf4301abfcf619be06 upstream.

bcm2835_pll_off is currently assigning CM_PLL_ANARST to the control
register, which may lose the other bits that are currently set by the
clock dividers.

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>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/clk/bcm/clk-bcm2835.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -910,8 +910,14 @@ static void bcm2835_pll_off(struct clk_h
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)