Orange Pi5 kernel

/*
 * Atmel SAMA5D2-Compatible Shutdown Controller (SHDWC) driver.
 * Found on some SoCs as the sama5d2 (obviously).
 *
 * Copyright (C) 2015 Atmel Corporation,
 *                    Nicolas Ferre <nicolas.ferre@atmel.com>
 *
 * 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 reg_config {
<------>struct shdwc_reg_config shdwc;
<------>struct pmc_reg_config pmc;
};
 
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 __init 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,
<------>},
};
 
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,
<------>},
};
 
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,
<------>}, {
<------><------>/*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" },
<------>{ /* Sentinel. */ }
};
 
static int __init at91_shdwc_probe(struct platform_device *pdev)
{
<------>struct resource *res;
<------>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);
 
<------>res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
<------>at91_shdwc->shdwc_base = devm_ioremap_resource(&pdev->dev, res);
<------>if (IS_ERR(at91_shdwc->shdwc_base)) {
<------><------>dev_err(&pdev->dev, "Could not map reset controller address\n");
<------><------>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;
<------>}
 
<------>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;
<------>}
 
<------>pm_power_off = at91_poweroff;
 
<------>ddr_type = readl(at91_shdwc->mpddrc_base + AT91_DDRSDRC_MDR) &
<------><------><------> AT91_DDRSDRC_MD;
<------>if (ddr_type != AT91_DDRSDRC_MD_LPDDR2 &&
<------>    ddr_type != AT91_DDRSDRC_MD_LPDDR3) {
<------><------>iounmap(at91_shdwc->mpddrc_base);
<------><------>at91_shdwc->mpddrc_base = NULL;
<------>}
 
<------>return 0;
 
unmap:
<------>iounmap(at91_shdwc->pmc_base);
clk_disable:
<------>clk_disable_unprepare(at91_shdwc->sclk);
 
<------>return ret;
}
 
static int __exit 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);
 
<------>return 0;
}
 
static struct platform_driver at91_shdwc_driver = {
<------>.remove = __exit_p(at91_shdwc_remove),
<------>.driver = {
<------><------>.name = "at91-shdwc",
<------><------>.of_match_table = at91_shdwc_of_match,
<------>},
};
module_platform_driver_probe(at91_shdwc_driver, at91_shdwc_probe);
 
MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>");
MODULE_DESCRIPTION("Atmel shutdown controller driver");
MODULE_LICENSE("GPL v2");