2019-05-20 11:43:14

by Nicolas Saenz Julienne

Subject: [RFC v2 2/5] clk: bcm2835: set pllb_arm divisor as readonly

This divisor is controlled by the firmware, we don't want the clock
subsystem to update it inadvertently.

Signed-off-by: Nicolas Saenz Julienne <[email protected]>
---
drivers/clk/bcm/clk-bcm2835.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index c2772dfb155a..5aea110672f3 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -465,6 +465,7 @@ struct bcm2835_pll_divider_data {
u32 hold_mask;
u32 fixed_divider;
u32 flags;
+ u32 div_flags;
};

struct bcm2835_clock_data {
@@ -1349,7 +1350,7 @@ bcm2835_register_pll_divider(struct bcm2835_cprman *cprman,
divider->div.reg = cprman->regs + data->a2w_reg;
divider->div.shift = A2W_PLL_DIV_SHIFT;
divider->div.width = A2W_PLL_DIV_BITS;
- divider->div.flags = CLK_DIVIDER_MAX_AT_ZERO;
+ divider->div.flags = data->div_flags | CLK_DIVIDER_MAX_AT_ZERO;
divider->div.lock = &cprman->regs_lock;
divider->div.hw.init = &init;
divider->div.table = NULL;
@@ -1676,7 +1677,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = {
.load_mask = CM_PLLB_LOADARM,
.hold_mask = CM_PLLB_HOLDARM,
.fixed_divider = 1,
- .flags = CLK_SET_RATE_PARENT | CLK_GET_RATE_NOCACHE),
+ .flags = CLK_SET_RATE_PARENT | CLK_GET_RATE_NOCACHE,
+ .div_flags = CLK_DIVIDER_READ_ONLY),

/*
* PLLC is the core PLL, used to drive the core VPU clock.
--
2.21.0

2019-05-20 12:19:20

by Stefan Wahren

Subject: Re: [RFC v2 2/5] clk: bcm2835: set pllb_arm divisor as readonly

On 20.05.19 12:47, Nicolas Saenz Julienne wrote:
> This divisor is controlled by the firmware, we don't want the clock
> subsystem to update it inadvertently.
>
> Signed-off-by: Nicolas Saenz Julienne <[email protected]>
Acked-by: Stefan Wahren <[email protected]>