46 lines
1.9 KiB
Diff
46 lines
1.9 KiB
Diff
From 91a49481af7332853c4c921d46aded8210572210 Mon Sep 17 00:00:00 2001
|
|
From: Claudiu Beznea <claudiu.beznea@microchip.com>
|
|
Date: Mon, 11 Oct 2021 14:27:17 +0300
|
|
Subject: [PATCH 245/247] clk: at91: sama7g5: remove prescaler part of master
|
|
clock
|
|
|
|
On SAMA7G5 the prescaler part of master clock has been implemented as a
|
|
changeable one. Everytime the prescaler is changed the PMC_SR.MCKRDY bit
|
|
must be polled. Value 1 for PMC_SR.MCKRDY means the prescaler update is
|
|
done. Driver polls for this bit until it becomes 1. On SAMA7G5 it has
|
|
been discovered that in some conditions the PMC_SR.MCKRDY is not rising
|
|
but the rate it provides it's stable. The workaround is to add a timeout
|
|
when polling for PMC_SR.MCKRDY. At the moment, for SAMA7G5, the prescaler
|
|
will be removed from Linux clock tree as all the frequencies for CPU could
|
|
be obtained from PLL and also there will be less overhead when changing
|
|
frequency via DVFS.
|
|
|
|
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
|
|
Link: https://lore.kernel.org/r/20211011112719.3951784-14-claudiu.beznea@microchip.com
|
|
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
|
|
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
|
|
---
|
|
drivers/clk/at91/sama7g5.c | 11 +----------
|
|
1 file changed, 1 insertion(+), 10 deletions(-)
|
|
|
|
--- a/drivers/clk/at91/sama7g5.c
|
|
+++ b/drivers/clk/at91/sama7g5.c
|
|
@@ -992,16 +992,7 @@ static void __init sama7g5_pmc_setup(str
|
|
}
|
|
|
|
parent_names[0] = "cpupll_divpmcck";
|
|
- hw = at91_clk_register_master_pres(regmap, "cpuck", 1, parent_names,
|
|
- &mck0_layout, &mck0_characteristics,
|
|
- &pmc_mck0_lock,
|
|
- CLK_SET_RATE_PARENT, 0);
|
|
- if (IS_ERR(hw))
|
|
- goto err_free;
|
|
-
|
|
- sama7g5_pmc->chws[PMC_CPU] = hw;
|
|
-
|
|
- hw = at91_clk_register_master_div(regmap, "mck0", "cpuck",
|
|
+ hw = at91_clk_register_master_div(regmap, "mck0", "cpupll_divpmcck",
|
|
&mck0_layout, &mck0_characteristics,
|
|
&pmc_mck0_lock, CLK_GET_RATE_NOCACHE, 5);
|
|
if (IS_ERR(hw))
|