95 lines
3.4 KiB
Diff
95 lines
3.4 KiB
Diff
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From 480a2a2365b4fda2c6bdb96a6ce8bc0b64899fe4 Mon Sep 17 00:00:00 2001
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From: Michael Lange <linuxstuff@milaw.biz>
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Date: Thu, 21 Jan 2016 18:10:16 +0100
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Subject: [PATCH 139/156] rtc: ds1307: add support for the DT property
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'wakeup-source'
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For RTC chips with no IRQ directly connected to the SoC, the RTC chip
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can be forced as a wakeup source by stating that explicitly in
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the device's .dts file using the "wakeup-source" boolean property.
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This will guarantee the 'wakealarm' sysfs entry is available on the
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device, if supported by the RTC.
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With these changes to the driver rtc-ds1307 and the necessary entries
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in the .dts file, I get an working ds1337 RTC on the Witty Pi extension
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board by UUGear for the Raspberry Pi.
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An example for the entry in the .dts file:
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rtc: ds1337@68 {
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compatible = "dallas,ds1337";
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reg = <0x68>;
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wakeup-source;
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If the "wakeup-source" property is set, do not request an IRQ.
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Set also UIE mode to unsupported, to get a working 'hwclock' binary.
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Signed-off-by: Michael Lange <linuxstuff@milaw.biz>
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Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
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---
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drivers/rtc/rtc-ds1307.c | 29 +++++++++++++++++++++++++++--
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1 file changed, 27 insertions(+), 2 deletions(-)
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--- a/drivers/rtc/rtc-ds1307.c
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+++ b/drivers/rtc/rtc-ds1307.c
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@@ -860,6 +860,7 @@ static int ds1307_probe(struct i2c_clien
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struct chip_desc *chip = &chips[id->driver_data];
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struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
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bool want_irq = false;
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+ bool ds1307_can_wakeup_device = false;
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unsigned char *buf;
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struct ds1307_platform_data *pdata = dev_get_platdata(&client->dev);
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irq_handler_t irq_handler = ds1307_irq;
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@@ -907,6 +908,20 @@ static int ds1307_probe(struct i2c_clien
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ds1307->write_block_data = ds1307_write_block_data;
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}
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+#ifdef CONFIG_OF
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+/*
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+ * For devices with no IRQ directly connected to the SoC, the RTC chip
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+ * can be forced as a wakeup source by stating that explicitly in
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+ * the device's .dts file using the "wakeup-source" boolean property.
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+ * If the "wakeup-source" property is set, don't request an IRQ.
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+ * This will guarantee the 'wakealarm' sysfs entry is available on the device,
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+ * if supported by the RTC.
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+ */
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+ if (of_property_read_bool(client->dev.of_node, "wakeup-source")) {
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+ ds1307_can_wakeup_device = true;
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+ }
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+#endif
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+
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switch (ds1307->type) {
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case ds_1337:
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case ds_1339:
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@@ -925,11 +940,13 @@ static int ds1307_probe(struct i2c_clien
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ds1307->regs[0] &= ~DS1337_BIT_nEOSC;
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/*
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- * Using IRQ? Disable the square wave and both alarms.
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+ * Using IRQ or defined as wakeup-source?
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+ * Disable the square wave and both alarms.
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* For some variants, be sure alarms can trigger when we're
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* running on Vbackup (BBSQI/BBSQW)
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*/
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- if (ds1307->client->irq > 0 && chip->alarm) {
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+ if (chip->alarm && (ds1307->client->irq > 0 ||
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+ ds1307_can_wakeup_device)) {
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ds1307->regs[0] |= DS1337_BIT_INTCN
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| bbsqi_bitpos[ds1307->type];
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ds1307->regs[0] &= ~(DS1337_BIT_A2IE | DS1337_BIT_A1IE);
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@@ -1144,6 +1161,14 @@ read_rtc:
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return PTR_ERR(ds1307->rtc);
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}
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+ if (ds1307_can_wakeup_device) {
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+ /* Disable request for an IRQ */
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+ want_irq = false;
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+ dev_info(&client->dev, "'wakeup-source' is set, request for an IRQ is disabled!\n");
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+ /* We cannot support UIE mode if we do not have an IRQ line */
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+ ds1307->rtc->uie_unsupported = 1;
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+ }
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+
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if (want_irq) {
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err = devm_request_threaded_irq(&client->dev,
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client->irq, NULL, irq_handler,
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