| /* |
| * 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/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(31, 16) |
| #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_RTCWKEN(cfg) (1 << ((cfg)->mr_rtcwk_shift)) |
| |
| #define DBC_PERIOD_US(x) DIV_ROUND_UP_ULL((1000000 * (x)), \ |
| SLOW_CLOCK_FREQ) |
| |
| struct shdwc_config { |
| u8 wkup_pin_input; |
| u8 mr_rtcwk_shift; |
| u8 sr_rtcwk_shift; |
| }; |
| |
| struct shdwc { |
| const struct shdwc_config *cfg; |
| void __iomem *at91_shdwc_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 struct clk *sclk; |
| static void __iomem *mpddrc_base; |
| |
| 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); |
| u32 reg; |
| char *reason = "unknown"; |
| |
| reg = readl(shdw->at91_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, shdw->cfg)) |
| reason = "WKUP pin"; |
| else if (SHDW_RTCWK(reg, shdw->cfg)) |
| reason = "RTC"; |
| |
| pr_info("AT91: Wake-Up source: %s\n", reason); |
| } |
| |
| static void at91_poweroff(void) |
| { |
| writel(AT91_SHDW_KEY | AT91_SHDW_SHDW, |
| at91_shdwc->at91_shdwc_base + AT91_SHDW_CR); |
| } |
| |
| static void at91_lpddr_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 */ |
| " str %1, [%0, #" __stringify(AT91_DDRSDRC_LPR) "]\n\t" |
| /* Shutdown CPU */ |
| " str %3, [%2, #" __stringify(AT91_SHDW_CR) "]\n\t" |
| |
| " b .\n\t" |
| : |
| : "r" (mpddrc_base), |
| "r" cpu_to_le32(AT91_DDRSDRC_LPDDR2_PWOFF), |
| "r" (at91_shdwc->at91_shdwc_base), |
| "r" cpu_to_le32(AT91_SHDW_KEY | AT91_SHDW_SHDW) |
| : "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); |
| 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(shdw->cfg); |
| |
| dev_dbg(&pdev->dev, "%s: mode = %#x\n", __func__, mode); |
| writel(mode, shdw->at91_shdwc_base + AT91_SHDW_MR); |
| |
| input = at91_shdwc_get_wakeup_input(pdev, np); |
| writel(input, shdw->at91_shdwc_base + AT91_SHDW_WUIR); |
| } |
| |
| static const struct shdwc_config sama5d2_shdwc_config = { |
| .wkup_pin_input = 0, |
| .mr_rtcwk_shift = 17, |
| .sr_rtcwk_shift = 5, |
| }; |
| |
| static const struct of_device_id at91_shdwc_of_match[] = { |
| { |
| .compatible = "atmel,sama5d2-shdwc", |
| .data = &sama5d2_shdwc_config, |
| }, { |
| /*sentinel*/ |
| } |
| }; |
| MODULE_DEVICE_TABLE(of, at91_shdwc_of_match); |
| |
| 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->at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res); |
| if (IS_ERR(at91_shdwc->at91_shdwc_base)) { |
| dev_err(&pdev->dev, "Could not map reset controller address\n"); |
| return PTR_ERR(at91_shdwc->at91_shdwc_base); |
| } |
| |
| match = of_match_node(at91_shdwc_of_match, pdev->dev.of_node); |
| at91_shdwc->cfg = match->data; |
| |
| sclk = devm_clk_get(&pdev->dev, NULL); |
| if (IS_ERR(sclk)) |
| return PTR_ERR(sclk); |
| |
| ret = clk_prepare_enable(sclk); |
| if (ret) { |
| dev_err(&pdev->dev, "Could not enable slow clock\n"); |
| return ret; |
| } |
| |
| at91_wakeup_status(pdev); |
| |
| at91_shdwc_dt_configure(pdev); |
| |
| pm_power_off = at91_poweroff; |
| |
| np = of_find_compatible_node(NULL, NULL, "atmel,sama5d3-ddramc"); |
| if (!np) |
| return 0; |
| |
| mpddrc_base = of_iomap(np, 0); |
| of_node_put(np); |
| |
| if (!mpddrc_base) |
| return 0; |
| |
| ddr_type = readl(mpddrc_base + AT91_DDRSDRC_MDR) & AT91_DDRSDRC_MD; |
| if ((ddr_type == AT91_DDRSDRC_MD_LPDDR2) || |
| (ddr_type == AT91_DDRSDRC_MD_LPDDR3)) |
| pm_power_off = at91_lpddr_poweroff; |
| else |
| iounmap(mpddrc_base); |
| |
| return 0; |
| } |
| |
| 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 == at91_lpddr_poweroff) |
| pm_power_off = NULL; |
| |
| /* Reset values to disable wake-up features */ |
| writel(0, shdw->at91_shdwc_base + AT91_SHDW_MR); |
| writel(0, shdw->at91_shdwc_base + AT91_SHDW_WUIR); |
| |
| clk_disable_unprepare(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"); |