Commit 55486091 authored by Eric Anholt's avatar Eric Anholt Committed by Stephen Boyd
Browse files

clk: bcm2835: Don't rate change PLLs on behalf of DSI PLL dividers. 



Our core PLLs are intended to be configured once and left alone.  With
the SET_RATE_PARENT, asking to set the PLLD_DSI1 clock rate would
change PLLD just to get closer to the requested DSI clock, thus
changing PLLD_PER, the UART and ethernet PHY clock rates downstream of
it, and breaking ethernet.

We *do* want PLLH to change so that PLLH_AUX can be exactly the value
we want, though.  Thus, we need to have a per-divider policy of
whether to pass rate changes up.

Signed-off-by: default avatarEric Anholt <eric@anholt.net>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent 0c744ea4

drivers/clk/bcm/clk-bcm2835.c

+28 −14
Original line number Diff line number Diff line
@@ -428,6 +428,7 @@ struct bcm2835_pll_divider_data { 
	u32 load_mask;

	u32 hold_mask;

	u32 fixed_divider;

	u32 flags;

};



struct bcm2835_clock_data {
@@ -1252,7 +1253,7 @@ bcm2835_register_pll_divider(struct bcm2835_cprman *cprman, 
	init.num_parents = 1;

	init.name = divider_name;

	init.ops = &bcm2835_pll_divider_clk_ops;

	init.flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED;

	init.flags = data->flags | CLK_IGNORE_UNUSED;



	divider = devm_kzalloc(cprman->dev, sizeof(*divider), GFP_KERNEL);

	if (!divider)
@@ -1466,7 +1467,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLA_CORE,

		.load_mask = CM_PLLA_LOADCORE,

		.hold_mask = CM_PLLA_HOLDCORE,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),

	[BCM2835_PLLA_PER]	= REGISTER_PLL_DIV(

		.name = "plla_per",

		.source_pll = "plla",
@@ -1474,7 +1476,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLA_PER,

		.load_mask = CM_PLLA_LOADPER,

		.hold_mask = CM_PLLA_HOLDPER,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),

	[BCM2835_PLLA_DSI0]	= REGISTER_PLL_DIV(

		.name = "plla_dsi0",

		.source_pll = "plla",
@@ -1490,7 +1493,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLA_CCP2,

		.load_mask = CM_PLLA_LOADCCP2,

		.hold_mask = CM_PLLA_HOLDCCP2,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),



	/* PLLB is used for the ARM's clock. */

	[BCM2835_PLLB]		= REGISTER_PLL(
@@ -1514,7 +1518,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLB_ARM,

		.load_mask = CM_PLLB_LOADARM,

		.hold_mask = CM_PLLB_HOLDARM,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),



	/*

	 * PLLC is the core PLL, used to drive the core VPU clock.
@@ -1543,7 +1548,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLC_CORE0,

		.load_mask = CM_PLLC_LOADCORE0,

		.hold_mask = CM_PLLC_HOLDCORE0,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),

	[BCM2835_PLLC_CORE1]	= REGISTER_PLL_DIV(

		.name = "pllc_core1",

		.source_pll = "pllc",
@@ -1551,7 +1557,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLC_CORE1,

		.load_mask = CM_PLLC_LOADCORE1,

		.hold_mask = CM_PLLC_HOLDCORE1,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),

	[BCM2835_PLLC_CORE2]	= REGISTER_PLL_DIV(

		.name = "pllc_core2",

		.source_pll = "pllc",
@@ -1559,7 +1566,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLC_CORE2,

		.load_mask = CM_PLLC_LOADCORE2,

		.hold_mask = CM_PLLC_HOLDCORE2,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),

	[BCM2835_PLLC_PER]	= REGISTER_PLL_DIV(

		.name = "pllc_per",

		.source_pll = "pllc",
@@ -1567,7 +1575,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLC_PER,

		.load_mask = CM_PLLC_LOADPER,

		.hold_mask = CM_PLLC_HOLDPER,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),



	/*

	 * PLLD is the display PLL, used to drive DSI display panels.
@@ -1596,7 +1605,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLD_CORE,

		.load_mask = CM_PLLD_LOADCORE,

		.hold_mask = CM_PLLD_HOLDCORE,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),

	[BCM2835_PLLD_PER]	= REGISTER_PLL_DIV(

		.name = "plld_per",

		.source_pll = "plld",
@@ -1604,7 +1614,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLD_PER,

		.load_mask = CM_PLLD_LOADPER,

		.hold_mask = CM_PLLD_HOLDPER,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),

	[BCM2835_PLLD_DSI0]	= REGISTER_PLL_DIV(

		.name = "plld_dsi0",

		.source_pll = "plld",
@@ -1649,7 +1660,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLH_RCAL,

		.load_mask = CM_PLLH_LOADRCAL,

		.hold_mask = 0,

		.fixed_divider = 10),

		.fixed_divider = 10,

		.flags = CLK_SET_RATE_PARENT),

	[BCM2835_PLLH_AUX]	= REGISTER_PLL_DIV(

		.name = "pllh_aux",

		.source_pll = "pllh",
@@ -1657,7 +1669,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLH_AUX,

		.load_mask = CM_PLLH_LOADAUX,

		.hold_mask = 0,

		.fixed_divider = 1),

		.fixed_divider = 1,

		.flags = CLK_SET_RATE_PARENT),

	[BCM2835_PLLH_PIX]	= REGISTER_PLL_DIV(

		.name = "pllh_pix",

		.source_pll = "pllh",
@@ -1665,7 +1678,8 @@ static const struct bcm2835_clk_desc clk_desc_array[] = { 
		.a2w_reg = A2W_PLLH_PIX,

		.load_mask = CM_PLLH_LOADPIX,

		.hold_mask = 0,

		.fixed_divider = 10),

		.fixed_divider = 10,

		.flags = CLK_SET_RATE_PARENT),



	/* the clocks */

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