2 * Gemini power management controller
3 * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
5 * Inspired by code from the SL3516 board support by Jason Lee
6 * Inspired by code from Janos Laube <janos.dev@gmail.com>
9 #include <linux/of_platform.h>
10 #include <linux/platform_device.h>
12 #include <linux/bitops.h>
13 #include <linux/interrupt.h>
15 #include <linux/reboot.h>
17 #define GEMINI_PWC_ID 0x00010500
18 #define GEMINI_PWC_IDREG 0x00
19 #define GEMINI_PWC_CTRLREG 0x04
20 #define GEMINI_PWC_STATREG 0x08
22 #define GEMINI_CTRL_SHUTDOWN BIT(0)
23 #define GEMINI_CTRL_ENABLE BIT(1)
24 #define GEMINI_CTRL_IRQ_CLR BIT(2)
26 #define GEMINI_STAT_CIR BIT(4)
27 #define GEMINI_STAT_RTC BIT(5)
28 #define GEMINI_STAT_POWERBUTTON BIT(6)
30 struct gemini_powercon {
35 static irqreturn_t gemini_powerbutton_interrupt(int irq, void *data)
37 struct gemini_powercon *gpw = data;
41 val = readl(gpw->base + GEMINI_PWC_CTRLREG);
42 val |= GEMINI_CTRL_IRQ_CLR;
43 writel(val, gpw->base + GEMINI_PWC_CTRLREG);
45 val = readl(gpw->base + GEMINI_PWC_STATREG);
49 dev_info(gpw->dev, "infrared poweroff\n");
50 orderly_poweroff(true);
53 dev_info(gpw->dev, "RTC poweroff\n");
54 orderly_poweroff(true);
56 case GEMINI_STAT_POWERBUTTON:
57 dev_info(gpw->dev, "poweroff button pressed\n");
58 orderly_poweroff(true);
61 dev_info(gpw->dev, "other power management IRQ\n");
68 /* This callback needs this static local as it has void as argument */
69 static struct gemini_powercon *gpw_poweroff;
71 static void gemini_poweroff(void)
73 struct gemini_powercon *gpw = gpw_poweroff;
76 dev_crit(gpw->dev, "Gemini power off\n");
77 val = readl(gpw->base + GEMINI_PWC_CTRLREG);
78 val |= GEMINI_CTRL_ENABLE | GEMINI_CTRL_IRQ_CLR;
79 writel(val, gpw->base + GEMINI_PWC_CTRLREG);
81 val &= ~GEMINI_CTRL_ENABLE;
82 val |= GEMINI_CTRL_SHUTDOWN;
83 writel(val, gpw->base + GEMINI_PWC_CTRLREG);
86 static int gemini_poweroff_probe(struct platform_device *pdev)
88 struct device *dev = &pdev->dev;
90 struct gemini_powercon *gpw;
95 gpw = devm_kzalloc(dev, sizeof(*gpw), GFP_KERNEL);
99 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
100 gpw->base = devm_ioremap_resource(dev, res);
101 if (IS_ERR(gpw->base))
102 return PTR_ERR(gpw->base);
104 irq = platform_get_irq(pdev, 0);
110 val = readl(gpw->base + GEMINI_PWC_IDREG);
112 if (val != GEMINI_PWC_ID) {
113 dev_err(dev, "wrong power controller ID: %08x\n",
118 /* Clear the power management IRQ */
119 val = readl(gpw->base + GEMINI_PWC_CTRLREG);
120 val |= GEMINI_CTRL_IRQ_CLR;
121 writel(val, gpw->base + GEMINI_PWC_CTRLREG);
123 ret = devm_request_irq(dev, irq, gemini_powerbutton_interrupt, 0,
128 pm_power_off = gemini_poweroff;
132 * Enable the power controller. This is crucial on Gemini
133 * systems: if this is not done, pressing the power button
134 * will result in unconditional poweroff without any warning.
135 * This makes the kernel handle the poweroff.
137 val = readl(gpw->base + GEMINI_PWC_CTRLREG);
138 val |= GEMINI_CTRL_ENABLE;
139 writel(val, gpw->base + GEMINI_PWC_CTRLREG);
141 dev_info(dev, "Gemini poweroff driver registered\n");
146 static const struct of_device_id gemini_poweroff_of_match[] = {
148 .compatible = "cortina,gemini-power-controller",
153 static struct platform_driver gemini_poweroff_driver = {
154 .probe = gemini_poweroff_probe,
156 .name = "gemini-poweroff",
157 .of_match_table = gemini_poweroff_of_match,
160 builtin_platform_driver(gemini_poweroff_driver);