Re: [PATCH] rtc: omap: Support regulator supply for RTC
From: Lokesh Vutla <hidden>
Date: 2014-09-19 09:48:44
+linux-omap, linux-arm-kernel, devicetree On Friday 19 September 2014 03:16 PM, Lokesh Vutla wrote:
quoted hunk
On some Soc's RTC is powered by an external power regulator. e.g. RTC on DRA7 SoC. Make the OMAP RTC driver support a power regulator. And also making the driver as module_platform_driver to support probe deferal. Signed-off-by: Lokesh Vutla <redacted> --- Tested on DRA7. Logs here: http://fpaste.org/134804/11200041/ Documentation/devicetree/bindings/rtc/rtc-omap.txt | 3 +++ drivers/rtc/rtc-omap.c | 28 ++++++++++++++++++++-- 2 files changed, 29 insertions(+), 2 deletions(-)diff --git a/Documentation/devicetree/bindings/rtc/rtc-omap.txt b/Documentation/devicetree/bindings/rtc/rtc-omap.txt index 5a0f02d..c9f963a 100644 --- a/Documentation/devicetree/bindings/rtc/rtc-omap.txt +++ b/Documentation/devicetree/bindings/rtc/rtc-omap.txt@@ -10,6 +10,9 @@ Required properties: - interrupts: rtc timer, alarm interrupts in order - interrupt-parent: phandle for the interrupt controller +Optional Properties: + - rtc-supply : phandle to the regulator device tree node if needed. + Example: rtc at 1c23000 {diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c index 21142e6..4473d1d 100644 --- a/drivers/rtc/rtc-omap.c +++ b/drivers/rtc/rtc-omap.c@@ -24,6 +24,7 @@ #include <linux/of_device.h> #include <linux/pm_runtime.h> #include <linux/io.h> +#include <linux/regulator/consumer.h> /* The OMAP1 RTC is a year/month/day/hours/minutes/seconds BCD clock * with century-range alarm matching, driven by the 32kHz clock.@@ -121,6 +122,7 @@ #define OMAP_RTC_HAS_32KCLK_EN BIT(2) static void __iomem *rtc_base; +static struct regulator *rtc_reg; #define rtc_read(addr) readb(rtc_base + (addr)) #define rtc_write(val, addr) writeb(val, rtc_base + (addr))@@ -372,11 +374,12 @@ static const struct of_device_id omap_rtc_of_match[] = { }; MODULE_DEVICE_TABLE(of, omap_rtc_of_match); -static int __init omap_rtc_probe(struct platform_device *pdev) +static int omap_rtc_probe(struct platform_device *pdev) { struct resource *res; struct rtc_device *rtc; u8 reg, new_ctrl; + int ret; const struct platform_device_id *id_entry; const struct of_device_id *of_id;@@ -402,6 +405,23 @@ static int __init omap_rtc_probe(struct platform_device *pdev) return -ENOENT; } + rtc_reg = devm_regulator_get_optional(&pdev->dev, "rtc"); + if (IS_ERR(rtc_reg)) { + if (PTR_ERR(rtc_reg) == -EPROBE_DEFER) { + dev_err(&pdev->dev, "regulator not ready, retry\n"); + return -EPROBE_DEFER; + } + rtc_reg = NULL; + } + + if (rtc_reg) { + ret = regulator_enable(rtc_reg); + if (ret) { + dev_dbg(&pdev->dev, "regulator enable failed\n"); + return ret; + } + } + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); rtc_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(rtc_base))@@ -517,6 +537,9 @@ static int __exit omap_rtc_remove(struct platform_device *pdev) pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); + if (rtc_reg) + regulator_disable(rtc_reg); + return 0; }@@ -565,6 +588,7 @@ static void omap_rtc_shutdown(struct platform_device *pdev) MODULE_ALIAS("platform:omap_rtc"); static struct platform_driver omap_rtc_driver = { + .probe = omap_rtc_probe, .remove = __exit_p(omap_rtc_remove), .shutdown = omap_rtc_shutdown, .driver = {@@ -576,7 +600,7 @@ static struct platform_driver omap_rtc_driver = { .id_table = omap_rtc_devtype, }; -module_platform_driver_probe(omap_rtc_driver, omap_rtc_probe); +module_platform_driver(omap_rtc_driver); MODULE_AUTHOR("George G. Davis (and others)"); MODULE_LICENSE("GPL");