linux-stable/drivers/clk/at91/at91sam9g45.c
Claudiu Beznea 7029db09b2 clk: at91: clk-master: add notifier for divider
SAMA7G5 supports DVFS by changing cpuck. On SAMA7G5 mck0 shares the same
parent with cpuck as seen in the following clock tree:

                       +----------> cpuck
                       |
FRAC PLL ---> DIV PLL -+-> DIV ---> mck0

mck0 could go b/w 32KHz and 200MHz on SAMA7G5. To avoid mck0 overclocking
while changing FRAC PLL or DIV PLL the commit implements a notifier for
mck0 which applies a safe divider to register (maximum value of the divider
which is 5) on PRE_RATE_CHANGE events (such that changes on PLL to not
overclock mck0) and sets the maximum allowed rate on POST_RATE_CHANGE
events.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20211011112719.3951784-13-claudiu.beznea@microchip.com
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2021-10-26 18:27:43 -07:00

231 lines
6.1 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 DEFINE_SPINLOCK(at91sam9g45_mck_lock);
static const struct clk_master_characteristics mck_characteristics = {
.output = { .min = 0, .max = 133333333 },
.divisors = { 1, 2, 4, 3 },
};
static u8 plla_out[] = { 0, 1, 2, 3, 0, 1, 2, 3 };
static u16 plla_icpll[] = { 0, 0, 0, 0, 1, 1, 1, 1 };
static const struct clk_range plla_outputs[] = {
{ .min = 745000000, .max = 800000000 },
{ .min = 695000000, .max = 750000000 },
{ .min = 645000000, .max = 700000000 },
{ .min = 595000000, .max = 650000000 },
{ .min = 545000000, .max = 600000000 },
{ .min = 495000000, .max = 555000000 },
{ .min = 445000000, .max = 500000000 },
{ .min = 400000000, .max = 450000000 },
};
static const struct clk_pll_characteristics plla_characteristics = {
.input = { .min = 2000000, .max = 32000000 },
.num_output = ARRAY_SIZE(plla_outputs),
.output = plla_outputs,
.icpll = plla_icpll,
.out = plla_out,
};
static const struct {
char *n;
char *p;
u8 id;
} at91sam9g45_systemck[] = {
{ .n = "ddrck", .p = "masterck_div", .id = 2 },
{ .n = "uhpck", .p = "usbck", .id = 6 },
{ .n = "pck0", .p = "prog0", .id = 8 },
{ .n = "pck1", .p = "prog1", .id = 9 },
};
struct pck {
char *n;
u8 id;
};
static const struct pck at91sam9g45_periphck[] = {
{ .n = "pioA_clk", .id = 2, },
{ .n = "pioB_clk", .id = 3, },
{ .n = "pioC_clk", .id = 4, },
{ .n = "pioDE_clk", .id = 5, },
{ .n = "trng_clk", .id = 6, },
{ .n = "usart0_clk", .id = 7, },
{ .n = "usart1_clk", .id = 8, },
{ .n = "usart2_clk", .id = 9, },
{ .n = "usart3_clk", .id = 10, },
{ .n = "mci0_clk", .id = 11, },
{ .n = "twi0_clk", .id = 12, },
{ .n = "twi1_clk", .id = 13, },
{ .n = "spi0_clk", .id = 14, },
{ .n = "spi1_clk", .id = 15, },
{ .n = "ssc0_clk", .id = 16, },
{ .n = "ssc1_clk", .id = 17, },
{ .n = "tcb0_clk", .id = 18, },
{ .n = "pwm_clk", .id = 19, },
{ .n = "adc_clk", .id = 20, },
{ .n = "dma0_clk", .id = 21, },
{ .n = "uhphs_clk", .id = 22, },
{ .n = "lcd_clk", .id = 23, },
{ .n = "ac97_clk", .id = 24, },
{ .n = "macb0_clk", .id = 25, },
{ .n = "isi_clk", .id = 26, },
{ .n = "udphs_clk", .id = 27, },
{ .n = "aestdessha_clk", .id = 28, },
{ .n = "mci1_clk", .id = 29, },
{ .n = "vdec_clk", .id = 30, },
};
static void __init at91sam9g45_pmc_setup(struct device_node *np)
{
const char *slck_name, *mainxtal_name;
struct pmc_data *at91sam9g45_pmc;
const char *parent_names[6];
struct regmap *regmap;
struct clk_hw *hw;
int i;
bool bypass;
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;
at91sam9g45_pmc = pmc_data_allocate(PMC_PLLACK + 1,
nck(at91sam9g45_systemck),
nck(at91sam9g45_periphck), 0, 2);
if (!at91sam9g45_pmc)
return;
bypass = of_property_read_bool(np, "atmel,osc-bypass");
hw = at91_clk_register_main_osc(regmap, "main_osc", mainxtal_name,
bypass);
if (IS_ERR(hw))
goto err_free;
hw = at91_clk_register_rm9200_main(regmap, "mainck", "main_osc");
if (IS_ERR(hw))
goto err_free;
at91sam9g45_pmc->chws[PMC_MAIN] = hw;
hw = at91_clk_register_pll(regmap, "pllack", "mainck", 0,
&at91rm9200_pll_layout, &plla_characteristics);
if (IS_ERR(hw))
goto err_free;
hw = at91_clk_register_plldiv(regmap, "plladivck", "pllack");
if (IS_ERR(hw))
goto err_free;
at91sam9g45_pmc->chws[PMC_PLLACK] = hw;
hw = at91_clk_register_utmi(regmap, NULL, "utmick", "mainck");
if (IS_ERR(hw))
goto err_free;
at91sam9g45_pmc->chws[PMC_UTMI] = hw;
parent_names[0] = slck_name;
parent_names[1] = "mainck";
parent_names[2] = "plladivck";
parent_names[3] = "utmick";
hw = at91_clk_register_master_pres(regmap, "masterck_pres", 4,
parent_names,
&at91rm9200_master_layout,
&mck_characteristics,
&at91sam9g45_mck_lock,
CLK_SET_RATE_GATE, INT_MIN);
if (IS_ERR(hw))
goto err_free;
hw = at91_clk_register_master_div(regmap, "masterck_div",
"masterck_pres",
&at91rm9200_master_layout,
&mck_characteristics,
&at91sam9g45_mck_lock,
CLK_SET_RATE_GATE, 0);
if (IS_ERR(hw))
goto err_free;
at91sam9g45_pmc->chws[PMC_MCK] = hw;
parent_names[0] = "plladivck";
parent_names[1] = "utmick";
hw = at91sam9x5_clk_register_usb(regmap, "usbck", parent_names, 2);
if (IS_ERR(hw))
goto err_free;
parent_names[0] = slck_name;
parent_names[1] = "mainck";
parent_names[2] = "plladivck";
parent_names[3] = "utmick";
parent_names[4] = "masterck_div";
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,
&at91sam9g45_programmable_layout,
NULL);
if (IS_ERR(hw))
goto err_free;
at91sam9g45_pmc->pchws[i] = hw;
}
for (i = 0; i < ARRAY_SIZE(at91sam9g45_systemck); i++) {
hw = at91_clk_register_system(regmap, at91sam9g45_systemck[i].n,
at91sam9g45_systemck[i].p,
at91sam9g45_systemck[i].id);
if (IS_ERR(hw))
goto err_free;
at91sam9g45_pmc->shws[at91sam9g45_systemck[i].id] = hw;
}
for (i = 0; i < ARRAY_SIZE(at91sam9g45_periphck); i++) {
hw = at91_clk_register_peripheral(regmap,
at91sam9g45_periphck[i].n,
"masterck_div",
at91sam9g45_periphck[i].id);
if (IS_ERR(hw))
goto err_free;
at91sam9g45_pmc->phws[at91sam9g45_periphck[i].id] = hw;
}
of_clk_add_hw_provider(np, of_clk_hw_pmc_get, at91sam9g45_pmc);
return;
err_free:
kfree(at91sam9g45_pmc);
}
/*
* The TCB is used as the clocksource so its clock is needed early. This means
* this can't be a platform driver.
*/
CLK_OF_DECLARE(at91sam9g45_pmc, "atmel,at91sam9g45-pmc", at91sam9g45_pmc_setup);