RTC support for NXP LPC18xx family

Add driver for the RTC found on NXP LPC178x/18xx/408x/43xx devices. The RTC provides calendar and clock functionality together with alarm interrupt support.

Signed-off-by Joachim Eastwood <[email protected]>

---

drivers/rtc/rtc-lpc24xx.c new file +23 -0

+static int lpc24xx_rtc_remove(struct platform_device *pdev)
+{
+	struct lpc24xx_rtc *rtc = platform_get_drvdata(pdev);
+
+	/* Ensure all interrupt sources are masked */
+	rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE);
+	rtc_writel(rtc, LPC24XX_CIIR, 0);
+
+	rtc_writel(rtc, LPC24XX_CCR, LPC178X_CCALEN);
+
+	clk_disable_unprepare(rtc->clk_rtc);
+	clk_disable_unprepare(rtc->clk_reg);
+
+	return 0;
+}
+
+static const struct of_device_id lpc24xx_rtc_match[] = {
+	{ .compatible = "nxp,lpc1788-rtc" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, lpc24xx_rtc_match);
+
+static struct platform_driver lpc24xx_rtc_driver = {

Quoted 6 lines · Joachim Eastwood

Add driver for the RTC found on NXP LPC178x/18xx/408x/43xx devices. The RTC provides calendar and clock functionality together with alarm interrupt support.

Signed-off-by Joachim Eastwood <[email protected]>

---

[..]

Quoted 27 lines

drivers/rtc/rtc-lpc24xx.c new file +27 -0

+static int lpc24xx_rtc_remove(struct platform_device *pdev)
+{
+     struct lpc24xx_rtc *rtc = platform_get_drvdata(pdev);
+
+     /* Ensure all interrupt sources are masked */
+     rtc_writel(rtc, LPC24XX_AMR, LPC24XX_ALARM_DISABLE);
+     rtc_writel(rtc, LPC24XX_CIIR, 0);
+
+     rtc_writel(rtc, LPC24XX_CCR, LPC178X_CCALEN);
+
+     clk_disable_unprepare(rtc->clk_rtc);
+     clk_disable_unprepare(rtc->clk_reg);
+
+     return 0;
+}
+
+static const struct of_device_id lpc24xx_rtc_match[] = {
+     { .compatible = "nxp,lpc1788-rtc" },
+     { }
+};
+MODULE_DEVICE_TABLE(of, lpc24xx_rtc_match);
+
+static struct platform_driver lpc24xx_rtc_driver = {
+     .probe  = lpc24xx_rtc_probe,
+     .remove = lpc24xx_rtc_remove,
+     .driver = {
+             .name = "lpc24xx-rtc",

drivers/rtc/rtc-lpc24xx.c line 308

Quoted 6 lines

drivers/rtc/rtc-lpc24xx.c new file +6 -0

+             .of_match_table = lpc24xx_rtc_match,
+     },
+};
+module_platform_driver(lpc24xx_rtc_driver);
+
+MODULE_AUTHOR("Kevin Wells <[email protected]");

Missing closing '>'.

Otherwise,

Reviewed-by Josh Cartwright <[email protected]>

Signed-off-by Joachim Eastwood <[email protected]>

---
 .../devicetree/bindings/rtc/nxp,lpc1788-rtc.txt     | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/rtc/nxp,lpc1788-rtc.txt

Documentation/devicetree/bindings/rtc/nxp,lpc1788-rtc.txt new file +0 -0

new file mode 100644
index 000000000000..ad41a040432c

Documentation/devicetree/bindings/rtc/nxp,lpc1788-rtc.txt new file +11 -0

+- clock-names	: Must contain "rtc" and "reg"
+  See ../clocks/clock-bindings.txt for details.
+
+Example:
+rtc: rtc at 40046000 {
+	compatible = "nxp,lpc1788-rtc";
+	reg = <0x40046000 0x1000>;
+	interrupts = <47>;
+	clocks = <&creg_clk 0>, <&ccu1 CLK_CPU_BUS>;
+	clock-names = "rtc", "reg";
+};

Quoted 5 lines

+Required properties:

+- compatible	: must contain "nxp,lpc1788-rtc"
+- reg		: Specifies base physical address and size of the registers.
+- interrupts	: A single interrupt specifier.
+- clocks	: Must contain entries for rtc and register clock

"Must contain clock specifiers for rtc and register clock" ?

This patch set adds support for the RTC found on many NXP devices including LPC178x/18xx/408x/43xx. The RTC provides calendar and clock functionality together with alarm interrupt support.

The driver is a rework of an old driver by Kevin Wells. It has been modified to support modern resource allocation, device tree and generally cleaned up. Driver was originally written to support the LPC24xx platform but since this platform isn't upstream support has been removed. The LPC24xx name is still kept to preserve the origin of this hardware block.

Been a while since the last version, but this version should address all comments from Josh and Alexandre on v2. There has also been some rework from my side. Please have a look.

changes since v2:
- rework hw init
- update Kconfig text
- remove unused registers defines
- misc clean ups
- rebase on 4.2-rc1

changes since v1:
- s/lpc2k/lpc24xx for better consistency
- fix Kconfig entry
- drop support for old versions for the ip block

Patch set is based on Linux v4.2-rc1.

Joachim Eastwood (2):
rtc: add rtc-lpc24xx driver
doc: dt: add documentation for nxp,lpc1788-rtc

Hi,

Quoted 29 lines · Joachim Eastwood

This patch set adds support for the RTC found on many NXP devices including LPC178x/18xx/408x/43xx. The RTC provides calendar and clock functionality together with alarm interrupt support.

The driver is a rework of an old driver by Kevin Wells. It has been modified to support modern resource allocation, device tree and generally cleaned up. Driver was originally written to support the LPC24xx platform but since this platform isn't upstream support has been removed. The LPC24xx name is still kept to preserve the origin of this hardware block.

Been a while since the last version, but this version should address all comments from Josh and Alexandre on v2. There has also been some rework from my side. Please have a look.

changes since v2:
- rework hw init
- update Kconfig text
- remove unused registers defines
- misc clean ups
- rebase on 4.2-rc1

changes since v1:
- s/lpc2k/lpc24xx for better consistency
- fix Kconfig entry
- drop support for old versions for the ip block

Patch set is based on Linux v4.2-rc1.

Quoted 4 lines

Joachim Eastwood (2):
rtc: add rtc-lpc24xx driver
doc: dt: add documentation for nxp,lpc1788-rtc

Applied both after adding a proper commit log to the second patch, reordering to avoid a checkpatch warning and fixing the typo in kevin's mail address.