Re: [PATCH v4 2/2] power: reset: at91-shdwc: add new shutdown controller driver
From: Alexandre Belloni <hidden>
Date: 2016-03-14 20:22:24
Also in:
linux-arm-kernel, lkml
On 10/03/2016 at 16:37:40 +0100, Nicolas Ferre wrote :
+ATMEL AT91 Alternative Shutdown Controller
Can't that be sama5d2 instead of alternative?
+M: Nicolas Ferre [off-list ref] +S: Supported +F: drivers/power/reset/at91-shdwc.c
I would also use that in the filename. Because once there is a third shdwc, I'm not sure how you will be able to name it.
+config POWER_RESET_AT91_SHDWC
I would also include that in the config name.
+ tristate "Atmel AT91 shutdown controller driver" + depends on ARCH_AT91 || COMPILE_TEST + default SOC_SAMA5 + help + This driver supports the alternate shutdown controller for some Atmel + SAMA5 SoCs. It is present for example on SAMA5D2 SoC. +
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/printk.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 {
+ 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 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);This is still not properly aligned :)
+}
+
+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);Alignment is not correct.
+ 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 %s\n",
+ cnp->full_name);
+ 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);Alignment is not correct -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html