/*
* Atmel SAMA5D2-Compatible Shutdown Controller (SHDWC) driver.
* Found on some SoCs as the sama5d2 (obviously).
*
* Copyright (C) 2015 Atmel Corporation,
* Nicolas Ferre <[email protected]>
*
* Evolved from driver at91-poweroff.c.
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*
* TODO:
* - addition to status of other wake-up inputs [1 - 15]
* - Analog Comparator wake-up alarm
* - Serial RX wake-up alarm
* - low power debouncer
*/
#include <linux/clk.h>
#include <linux/clk/at91_pmc.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <soc/at91/at91sam9_ddrsdr.h>
#define SLOW_CLOCK_FREQ 32768
#define AT91_SHDW_CR 0x00 /* Shut Down Control Register */
#define AT91_SHDW_SHDW BIT(0) /* Shut Down command */
#define AT91_SHDW_KEY (0xa5UL << 24) /* KEY Password */
#define AT91_SHDW_MR 0x04 /* Shut Down Mode Register */
#define AT91_SHDW_WKUPDBC_SHIFT 24
#define AT91_SHDW_WKUPDBC_MASK GENMASK(26, 24)
#define AT91_SHDW_WKUPDBC(x) (((x) << AT91_SHDW_WKUPDBC_SHIFT) \
& AT91_SHDW_WKUPDBC_MASK)
#define AT91_SHDW_SR 0x08 /* Shut Down Status Register */
#define AT91_SHDW_WKUPIS_SHIFT 16
#define AT91_SHDW_WKUPIS_MASK GENMASK(31, 16)
#define AT91_SHDW_WKUPIS(x) ((1 << (x)) << AT91_SHDW_WKUPIS_SHIFT \
& AT91_SHDW_WKUPIS_MASK)
#define AT91_SHDW_WUIR 0x0c /* Shutdown Wake-up Inputs Register */
#define AT91_SHDW_WKUPEN_MASK GENMASK(15, 0)
#define AT91_SHDW_WKUPEN(x) ((1 << (x)) & AT91_SHDW_WKUPEN_MASK)
#define AT91_SHDW_WKUPT_SHIFT 16
#define AT91_SHDW_WKUPT_MASK GENMASK(31, 16)
#define AT91_SHDW_WKUPT(x) ((1 << (x)) << AT91_SHDW_WKUPT_SHIFT \
& AT91_SHDW_WKUPT_MASK)
#define SHDW_WK_PIN(reg, cfg) ((reg) & AT91_SHDW_WKUPIS((cfg)->wkup_pin_input))
#define SHDW_RTCWK(reg, cfg) (((reg) >> ((cfg)->sr_rtcwk_shift)) & 0x1)
#define SHDW_RTTWK(reg, cfg) (((reg) >> ((cfg)->sr_rttwk_shift)) & 0x1)
#define SHDW_RTCWKEN(cfg) (1 << ((cfg)->mr_rtcwk_shift))
#define SHDW_RTTWKEN(cfg) (1 << ((cfg)->mr_rttwk_shift))
#define DBC_PERIOD_US(x) DIV_ROUND_UP_ULL((1000000 * (x)), \
SLOW_CLOCK_FREQ)
#define SHDW_CFG_NOT_USED (32)
struct shdwc_reg_config {
u8 wkup_pin_input;
u8 mr_rtcwk_shift;
u8 mr_rttwk_shift;
u8 sr_rtcwk_shift;
u8 sr_rttwk_shift;
};
struct pmc_reg_config {
u8 mckr;
};
struct ddrc_reg_config {
u32 type_offset;
u32 type_mask;
};
struct reg_config {
struct shdwc_reg_config shdwc;
struct pmc_reg_config pmc;
struct ddrc_reg_config ddrc;
};
struct shdwc {
const struct reg_config *rcfg;
struct clk *sclk;
void __iomem *shdwc_base;
void __iomem *mpddrc_base;
void __iomem *pmc_base;
};
/*
* Hold configuration here, cannot be more than one instance of the driver
* since pm_power_off itself is global.
*/
static struct shdwc *at91_shdwc;
static const unsigned long long sdwc_dbc_period[] = {
0, 3, 32, 512, 4096, 32768,
};
static void at91_wakeup_status(struct platform_device *pdev)
{
struct shdwc *shdw = platform_get_drvdata(pdev);
const struct reg_config *rcfg = shdw->rcfg;
u32 reg;
char *reason = "unknown";
reg = readl(shdw->shdwc_base + AT91_SHDW_SR);
dev_dbg(&pdev->dev, "%s: status = %#x\n", __func__, reg);
/* Simple power-on, just bail out */
if (!reg)
return;
if (SHDW_WK_PIN(reg, &rcfg->shdwc))
reason = "WKUP pin";
else if (SHDW_RTCWK(reg, &rcfg->shdwc))
reason = "RTC";
else if (SHDW_RTTWK(reg, &rcfg->shdwc))
reason = "RTT";
pr_info("AT91: Wake-Up source: %s\n", reason);
}
static void at91_poweroff(void)
{
asm volatile(
/* Align to cache lines */
".balign 32\n\t"
/* Ensure AT91_SHDW_CR is in the TLB by reading it */
" ldr r6, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
/* Power down SDRAM0 */
" tst %0, #0\n\t"
" beq 1f\n\t"
" str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t"
/* Switch the master clock source to slow clock. */
"1: ldr r6, [%4, %5]\n\t"
" bic r6, r6, #" __stringify(AT91_PMC_CSS) "\n\t"
" str r6, [%4, %5]\n\t"
/* Wait for clock switch. */
"2: ldr r6, [%4, #" __stringify(AT91_PMC_SR) "]\n\t"
" tst r6, #" __stringify(AT91_PMC_MCKRDY) "\n\t"
" beq 2b\n\t"
/* Shutdown CPU */
" str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t"
" b .\n\t"
:
: "r" (at91_shdwc->mpddrc_base),
"r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF),
"r" (at91_shdwc->shdwc_base),
"r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW),
"r" (at91_shdwc->pmc_base),
"r" (at91_shdwc->rcfg->pmc.mckr)
: "r6");
}
static u32 at91_shdwc_debouncer_value(struct platform_device *pdev,
u32 in_period_us)
{
int i;
int max_idx = ARRAY_SIZE(sdwc_dbc_period) - 1;
unsigned long long period_us;
unsigned long long max_period_us = DBC_PERIOD_US(sdwc_dbc_period[max_idx]);
if (in_period_us > max_period_us) {
dev_warn(&pdev->dev,
"debouncer period %u too big, reduced to %llu us\n",
in_period_us, max_period_us);
return max_idx;
}
for (i = max_idx - 1; i > 0; i--) {
period_us = DBC_PERIOD_US(sdwc_dbc_period[i]);
dev_dbg(&pdev->dev, "%s: ref[%d] = %llu\n",
__func__, i, period_us);
if (in_period_us > period_us)
break;
}
return i + 1;
}
static u32 at91_shdwc_get_wakeup_input(struct platform_device *pdev,
struct device_node *np)
{
struct device_node *cnp;
u32 wk_input_mask;
u32 wuir = 0;
u32 wk_input;
for_each_child_of_node(np, cnp) {
if (of_property_read_u32(cnp, "reg", &wk_input)) {
dev_warn(&pdev->dev, "reg property is missing for %pOF\n",
cnp);
continue;
}
wk_input_mask = 1 << wk_input;
if (!(wk_input_mask & AT91_SHDW_WKUPEN_MASK)) {
dev_warn(&pdev->dev,
"wake-up input %d out of bounds ignore\n",
wk_input);
continue;
}
wuir |= wk_input_mask;
if (of_property_read_bool(cnp, "atmel,wakeup-active-high"))
wuir |= AT91_SHDW_WKUPT(wk_input);
dev_dbg(&pdev->dev, "%s: (child %d) wuir = %#x\n",
__func__, wk_input, wuir);
}
return wuir;
}
static void at91_shdwc_dt_configure(struct platform_device *pdev)
{
struct shdwc *shdw = platform_get_drvdata(pdev);
const struct reg_config *rcfg = shdw->rcfg;
struct device_node *np = pdev->dev.of_node;
u32 mode = 0, tmp, input;
if (!np) {
dev_err(&pdev->dev, "device node not found\n");
return;
}
if (!of_property_read_u32(np, "debounce-delay-us", &tmp))
mode |= AT91_SHDW_WKUPDBC(at91_shdwc_debouncer_value(pdev, tmp));
if (of_property_read_bool(np, "atmel,wakeup-rtc-timer"))
mode |= SHDW_RTCWKEN(&rcfg->shdwc);
if (of_property_read_bool(np, "atmel,wakeup-rtt-timer"))
mode |= SHDW_RTTWKEN(&rcfg->shdwc);
dev_dbg(&pdev->dev, "%s: mode = %#x\n", __func__, mode);
writel(mode, shdw->shdwc_base + AT91_SHDW_MR);
input = at91_shdwc_get_wakeup_input(pdev, np);
writel(input, shdw->shdwc_base + AT91_SHDW_WUIR);
}
static const struct reg_config sama5d2_reg_config = {
.shdwc = {
.wkup_pin_input = 0,
.mr_rtcwk_shift = 17,
.mr_rttwk_shift = SHDW_CFG_NOT_USED,
.sr_rtcwk_shift = 5,
.sr_rttwk_shift = SHDW_CFG_NOT_USED,
},
.pmc = {
.mckr = 0x30,
},
.ddrc = {
.type_offset = AT91_DDRSDRC_MDR,
.type_mask = AT91_DDRSDRC_MD
},
};
static const struct reg_config sam9x60_reg_config = {
.shdwc = {
.wkup_pin_input = 0,
.mr_rtcwk_shift = 17,
.mr_rttwk_shift = 16,
.sr_rtcwk_shift = 5,
.sr_rttwk_shift = 4,
},
.pmc = {
.mckr = 0x28,
},
.ddrc = {
.type_offset = AT91_DDRSDRC_MDR,
.type_mask = AT91_DDRSDRC_MD
},
};
static const struct reg_config sama7g5_reg_config = {
.shdwc = {
.wkup_pin_input = 0,
.mr_rtcwk_shift = 17,
.mr_rttwk_shift = 16,
.sr_rtcwk_shift = 5,
.sr_rttwk_shift = 4,
},
.pmc = {
.mckr = 0x28,
},
};
static const struct of_device_id at91_shdwc_of_match[] = {
{
.compatible = "atmel,sama5d2-shdwc",
.data = &sama5d2_reg_config,
},
{
.compatible = "microchip,sam9x60-shdwc",
.data = &sam9x60_reg_config,
},
{
.compatible = "microchip,sama7g5-shdwc",
.data = &sama7g5_reg_config,
}, {
/*sentinel*/
}
};
MODULE_DEVICE_TABLE(of, at91_shdwc_of_match);
static const struct of_device_id at91_pmc_ids[] = {
{ .compatible = "atmel,sama5d2-pmc" },
{ .compatible = "microchip,sam9x60-pmc" },
{ .compatible = "microchip,sama7g5-pmc" },
{ /* Sentinel. */ }
};
static int at91_shdwc_probe(struct platform_device *pdev)
{
const struct of_device_id *match;
struct device_node *np;
u32 ddr_type;
int ret;
if (!pdev->dev.of_node)
return -ENODEV;
if (at91_shdwc)
return -EBUSY;
at91_shdwc = devm_kzalloc(&pdev->dev, sizeof(*at91_shdwc), GFP_KERNEL);
if (!at91_shdwc)
return -ENOMEM;
platform_set_drvdata(pdev, at91_shdwc);
at91_shdwc->shdwc_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(at91_shdwc->shdwc_base))
return PTR_ERR(at91_shdwc->shdwc_base);
match = of_match_node(at91_shdwc_of_match, pdev->dev.of_node);
at91_shdwc->rcfg = match->data;
at91_shdwc->sclk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(at91_shdwc->sclk))
return PTR_ERR(at91_shdwc->sclk);
ret = clk_prepare_enable(at91_shdwc->sclk);
if (ret) {
dev_err(&pdev->dev, "Could not enable slow clock\n");
return ret;
}
at91_wakeup_status(pdev);
at91_shdwc_dt_configure(pdev);
np = of_find_matching_node(NULL, at91_pmc_ids);
if (!np) {
ret = -ENODEV;
goto clk_disable;
}
at91_shdwc->pmc_base = of_iomap(np, 0);
of_node_put(np);
if (!at91_shdwc->pmc_base) {
ret = -ENOMEM;
goto clk_disable;
}
if (at91_shdwc->rcfg->ddrc.type_mask) {
np = of_find_compatible_node(NULL, NULL,
"atmel,sama5d3-ddramc");
if (!np) {
ret = -ENODEV;
goto unmap;
}
at91_shdwc->mpddrc_base = of_iomap(np, 0);
of_node_put(np);
if (!at91_shdwc->mpddrc_base) {
ret = -ENOMEM;
goto unmap;
}
ddr_type = readl(at91_shdwc->mpddrc_base +
at91_shdwc->rcfg->ddrc.type_offset) &
at91_shdwc->rcfg->ddrc.type_mask;
if (ddr_type != AT91_DDRSDRC_MD_LPDDR2 &&
ddr_type != AT91_DDRSDRC_MD_LPDDR3) {
iounmap(at91_shdwc->mpddrc_base);
at91_shdwc->mpddrc_base = NULL;
}
}
pm_power_off = at91_poweroff;
return 0;
unmap:
iounmap(at91_shdwc->pmc_base);
clk_disable:
clk_disable_unprepare(at91_shdwc->sclk);
return ret;
}
static void at91_shdwc_remove(struct platform_device *pdev)
{
struct shdwc *shdw = platform_get_drvdata(pdev);
if (pm_power_off == at91_poweroff)
pm_power_off = NULL;
/* Reset values to disable wake-up features */
writel(0, shdw->shdwc_base + AT91_SHDW_MR);
writel(0, shdw->shdwc_base + AT91_SHDW_WUIR);
if (shdw->mpddrc_base)
iounmap(shdw->mpddrc_base);
iounmap(shdw->pmc_base);
clk_disable_unprepare(shdw->sclk);
}
static struct platform_driver at91_shdwc_driver = {
.probe = at91_shdwc_probe,
.remove_new = at91_shdwc_remove,
.driver = {
.name = "at91-shdwc",
.of_match_table = at91_shdwc_of_match,
},
};
module_platform_driver(at91_shdwc_driver);
MODULE_AUTHOR("Nicolas Ferre <[email protected]>");
MODULE_DESCRIPTION("Atmel shutdown controller driver");
MODULE_LICENSE("GPL v2");
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