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

Commit Message

Nicolas Saenz Julienne May 20, 2019, 10:47 a.m. UTC

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

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

Comments

Stefan Wahren May 20, 2019, 11:43 a.m. UTC | #1

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 <[e-mail]>
Acked-by: Stefan Wahren <[e-mail]>

Patch

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.