alistair23-linux/drivers/clk/at91/at91sam9rl.c
Alexandre Belloni 90fe4a9708 clk: at91: fix possible deadlock
[ Upstream commit 6956eb33ab ]

Lockdep warns about a possible circular locking dependency because using
syscon_node_to_regmap() will make the created regmap get and enable the
first clock it can parse from the device tree. This clock is not needed to
access the registers and should not be enabled at that time.

Use the recently introduced device_node_to_regmap to solve that as it looks
up the regmap in the same list but doesn't care about the clocks.

Reported-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lkml.kernel.org/r/20191128102531.817549-1-alexandre.belloni@bootlin.com
Tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-12 12:21:34 +01:00

172 lines
4.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/clk-provider.h>
#include <linux/mfd/syscon.h>
#include <linux/slab.h>
#include <dt-bindings/clock/at91.h>
#include "pmc.h"
static const struct clk_master_characteristics sam9rl_mck_characteristics = {
.output = { .min = 0, .max = 94000000 },
.divisors = { 1, 2, 4, 0 },
};
static u8 sam9rl_plla_out[] = { 0, 2 };
static const struct clk_range sam9rl_plla_outputs[] = {
{ .min = 80000000, .max = 200000000 },
{ .min = 190000000, .max = 240000000 },
};
static const struct clk_pll_characteristics sam9rl_plla_characteristics = {
.input = { .min = 1000000, .max = 32000000 },
.num_output = ARRAY_SIZE(sam9rl_plla_outputs),
.output = sam9rl_plla_outputs,
.out = sam9rl_plla_out,
};
static const struct {
char *n;
char *p;
u8 id;
} at91sam9rl_systemck[] = {
{ .n = "pck0", .p = "prog0", .id = 8 },
{ .n = "pck1", .p = "prog1", .id = 9 },
};
static const struct {
char *n;
u8 id;
} at91sam9rl_periphck[] = {
{ .n = "pioA_clk", .id = 2, },
{ .n = "pioB_clk", .id = 3, },
{ .n = "pioC_clk", .id = 4, },
{ .n = "pioD_clk", .id = 5, },
{ .n = "usart0_clk", .id = 6, },
{ .n = "usart1_clk", .id = 7, },
{ .n = "usart2_clk", .id = 8, },
{ .n = "usart3_clk", .id = 9, },
{ .n = "mci0_clk", .id = 10, },
{ .n = "twi0_clk", .id = 11, },
{ .n = "twi1_clk", .id = 12, },
{ .n = "spi0_clk", .id = 13, },
{ .n = "ssc0_clk", .id = 14, },
{ .n = "ssc1_clk", .id = 15, },
{ .n = "tc0_clk", .id = 16, },
{ .n = "tc1_clk", .id = 17, },
{ .n = "tc2_clk", .id = 18, },
{ .n = "pwm_clk", .id = 19, },
{ .n = "adc_clk", .id = 20, },
{ .n = "dma0_clk", .id = 21, },
{ .n = "udphs_clk", .id = 22, },
{ .n = "lcd_clk", .id = 23, },
};
static void __init at91sam9rl_pmc_setup(struct device_node *np)
{
const char *slck_name, *mainxtal_name;
struct pmc_data *at91sam9rl_pmc;
const char *parent_names[6];
struct regmap *regmap;
struct clk_hw *hw;
int i;
i = of_property_match_string(np, "clock-names", "slow_clk");
if (i < 0)
return;
slck_name = of_clk_get_parent_name(np, i);
i = of_property_match_string(np, "clock-names", "main_xtal");
if (i < 0)
return;
mainxtal_name = of_clk_get_parent_name(np, i);
regmap = device_node_to_regmap(np);
if (IS_ERR(regmap))
return;
at91sam9rl_pmc = pmc_data_allocate(PMC_MAIN + 1,
nck(at91sam9rl_systemck),
nck(at91sam9rl_periphck), 0);
if (!at91sam9rl_pmc)
return;
hw = at91_clk_register_rm9200_main(regmap, "mainck", mainxtal_name);
if (IS_ERR(hw))
goto err_free;
at91sam9rl_pmc->chws[PMC_MAIN] = hw;
hw = at91_clk_register_pll(regmap, "pllack", "mainck", 0,
&at91rm9200_pll_layout,
&sam9rl_plla_characteristics);
if (IS_ERR(hw))
goto err_free;
hw = at91_clk_register_utmi(regmap, NULL, "utmick", "mainck");
if (IS_ERR(hw))
goto err_free;
at91sam9rl_pmc->chws[PMC_UTMI] = hw;
parent_names[0] = slck_name;
parent_names[1] = "mainck";
parent_names[2] = "pllack";
parent_names[3] = "utmick";
hw = at91_clk_register_master(regmap, "masterck", 4, parent_names,
&at91rm9200_master_layout,
&sam9rl_mck_characteristics);
if (IS_ERR(hw))
goto err_free;
at91sam9rl_pmc->chws[PMC_MCK] = hw;
parent_names[0] = slck_name;
parent_names[1] = "mainck";
parent_names[2] = "pllack";
parent_names[3] = "utmick";
parent_names[4] = "masterck";
for (i = 0; i < 2; i++) {
char name[6];
snprintf(name, sizeof(name), "prog%d", i);
hw = at91_clk_register_programmable(regmap, name,
parent_names, 5, i,
&at91rm9200_programmable_layout);
if (IS_ERR(hw))
goto err_free;
}
for (i = 0; i < ARRAY_SIZE(at91sam9rl_systemck); i++) {
hw = at91_clk_register_system(regmap, at91sam9rl_systemck[i].n,
at91sam9rl_systemck[i].p,
at91sam9rl_systemck[i].id);
if (IS_ERR(hw))
goto err_free;
at91sam9rl_pmc->shws[at91sam9rl_systemck[i].id] = hw;
}
for (i = 0; i < ARRAY_SIZE(at91sam9rl_periphck); i++) {
hw = at91_clk_register_peripheral(regmap,
at91sam9rl_periphck[i].n,
"masterck",
at91sam9rl_periphck[i].id);
if (IS_ERR(hw))
goto err_free;
at91sam9rl_pmc->phws[at91sam9rl_periphck[i].id] = hw;
}
of_clk_add_hw_provider(np, of_clk_hw_pmc_get, at91sam9rl_pmc);
return;
err_free:
pmc_data_free(at91sam9rl_pmc);
}
CLK_OF_DECLARE_DRIVER(at91sam9rl_pmc, "atmel,at91sam9rl-pmc", at91sam9rl_pmc_setup);