![Guenter Roeck](/assets/img/avatar_default.png)
at91_poweroff_get_wakeup_mode can return a negative error code and should therefore not return an enum type. Similar, its result should not be assigned to an enum type. Otherwise, the returned value is never negative, resulting in a compiler warning and a missed error condition, which in turn results in writing bad values into a chip register. Also fix other compiler warnings which can be easily avoided. drivers/power/reset/at91-poweroff.c:74:24: warning: type qualifiers ignored on function return type drivers/power/reset/at91-poweroff.c:74:24: warning: no previous prototype for 'at91_poweroff_get_wakeup_mode' drivers/power/reset/at91-poweroff.c:83:16: warning: comparison between signed and unsigned integer expressions drivers/power/reset/at91-poweroff.c:97:2: warning: comparison of unsigned expression < 0 is always false Cc: Maxime Ripard <maxime.ripard@free-electrons.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Sebastian Reichel <sre@kernel.org>
158 lines
4.3 KiB
C
158 lines
4.3 KiB
C
/*
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* Atmel AT91 SAM9 SoCs reset code
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*
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* Copyright (C) 2007 Atmel Corporation.
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* Copyright (C) 2011 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
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* Copyright (C) 2014 Free Electrons
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/printk.h>
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#define AT91_SHDW_CR 0x00 /* Shut Down Control Register */
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#define AT91_SHDW_SHDW BIT(0) /* Shut Down command */
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#define AT91_SHDW_KEY (0xa5 << 24) /* KEY Password */
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#define AT91_SHDW_MR 0x04 /* Shut Down Mode Register */
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#define AT91_SHDW_WKMODE0 GENMASK(2, 0) /* Wake-up 0 Mode Selection */
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#define AT91_SHDW_CPTWK0_MAX 0xf /* Maximum Counter On Wake Up 0 */
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#define AT91_SHDW_CPTWK0 (AT91_SHDW_CPTWK0_MAX << 4) /* Counter On Wake Up 0 */
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#define AT91_SHDW_CPTWK0_(x) ((x) << 4)
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#define AT91_SHDW_RTTWKEN BIT(16) /* Real Time Timer Wake-up Enable */
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#define AT91_SHDW_RTCWKEN BIT(17) /* Real Time Clock Wake-up Enable */
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#define AT91_SHDW_SR 0x08 /* Shut Down Status Register */
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#define AT91_SHDW_WAKEUP0 BIT(0) /* Wake-up 0 Status */
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#define AT91_SHDW_RTTWK BIT(16) /* Real-time Timer Wake-up */
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#define AT91_SHDW_RTCWK BIT(17) /* Real-time Clock Wake-up [SAM9RL] */
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enum wakeup_type {
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AT91_SHDW_WKMODE0_NONE = 0,
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AT91_SHDW_WKMODE0_HIGH = 1,
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AT91_SHDW_WKMODE0_LOW = 2,
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AT91_SHDW_WKMODE0_ANYLEVEL = 3,
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};
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static const char *shdwc_wakeup_modes[] = {
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[AT91_SHDW_WKMODE0_NONE] = "none",
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[AT91_SHDW_WKMODE0_HIGH] = "high",
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[AT91_SHDW_WKMODE0_LOW] = "low",
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[AT91_SHDW_WKMODE0_ANYLEVEL] = "any",
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};
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static void __iomem *at91_shdwc_base;
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static void __init at91_wakeup_status(void)
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{
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u32 reg = readl(at91_shdwc_base + AT91_SHDW_SR);
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char *reason = "unknown";
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/* Simple power-on, just bail out */
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if (!reg)
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return;
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if (reg & AT91_SHDW_RTTWK)
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reason = "RTT";
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else if (reg & AT91_SHDW_RTCWK)
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reason = "RTC";
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pr_info("AT91: Wake-Up source: %s\n", reason);
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}
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static void at91_poweroff(void)
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{
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writel(AT91_SHDW_KEY | AT91_SHDW_SHDW, at91_shdwc_base + AT91_SHDW_CR);
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}
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static int at91_poweroff_get_wakeup_mode(struct device_node *np)
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{
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const char *pm;
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unsigned int i;
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int err;
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err = of_property_read_string(np, "atmel,wakeup-mode", &pm);
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if (err < 0)
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return AT91_SHDW_WKMODE0_ANYLEVEL;
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for (i = 0; i < ARRAY_SIZE(shdwc_wakeup_modes); i++)
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if (!strcasecmp(pm, shdwc_wakeup_modes[i]))
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return i;
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return -ENODEV;
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}
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static void at91_poweroff_dt_set_wakeup_mode(struct platform_device *pdev)
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{
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struct device_node *np = pdev->dev.of_node;
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int wakeup_mode;
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u32 mode = 0, tmp;
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wakeup_mode = at91_poweroff_get_wakeup_mode(np);
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if (wakeup_mode < 0) {
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dev_warn(&pdev->dev, "shdwc unknown wakeup mode\n");
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return;
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}
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if (!of_property_read_u32(np, "atmel,wakeup-counter", &tmp)) {
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if (tmp > AT91_SHDW_CPTWK0_MAX) {
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dev_warn(&pdev->dev,
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"shdwc wakeup counter 0x%x > 0x%x reduce it to 0x%x\n",
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tmp, AT91_SHDW_CPTWK0_MAX, AT91_SHDW_CPTWK0_MAX);
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tmp = AT91_SHDW_CPTWK0_MAX;
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}
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mode |= AT91_SHDW_CPTWK0_(tmp);
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}
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if (of_property_read_bool(np, "atmel,wakeup-rtc-timer"))
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mode |= AT91_SHDW_RTCWKEN;
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if (of_property_read_bool(np, "atmel,wakeup-rtt-timer"))
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mode |= AT91_SHDW_RTTWKEN;
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writel(wakeup_mode | mode, at91_shdwc_base + AT91_SHDW_MR);
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}
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static int at91_poweroff_probe(struct platform_device *pdev)
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{
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struct resource *res;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(at91_shdwc_base)) {
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dev_err(&pdev->dev, "Could not map reset controller address\n");
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return PTR_ERR(at91_shdwc_base);
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}
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at91_wakeup_status();
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if (pdev->dev.of_node)
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at91_poweroff_dt_set_wakeup_mode(pdev);
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pm_power_off = at91_poweroff;
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return 0;
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}
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static struct of_device_id at91_poweroff_of_match[] = {
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{ .compatible = "atmel,at91sam9260-shdwc", },
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{ .compatible = "atmel,at91sam9rl-shdwc", },
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{ .compatible = "atmel,at91sam9x5-shdwc", },
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{ /*sentinel*/ }
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};
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static struct platform_driver at91_poweroff_driver = {
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.probe = at91_poweroff_probe,
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.driver = {
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.name = "at91-poweroff",
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.of_match_table = at91_poweroff_of_match,
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},
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};
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module_platform_driver(at91_poweroff_driver);
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