Re: [PATCH v3 2/2] drivers: rtc: add xilinx zynqmp rtc driver
From: Moritz Fischer
Date: Wed Aug 19 2015 - 14:19:53 EST
Hi Suneel,
looks good, minor nit below.
On Wed, Aug 19, 2015 at 2:53 AM, Suneel Garapati
<suneel.garapati@xxxxxxxxxx> wrote:
> adds support for RTC controller found on
> Xilinx Zynq Ultrascale+ MPSoC platform.
>
> Signed-off-by: Suneel Garapati <suneel.garapati@xxxxxxxxxx>
> ---
> Changes v3
> - fix checkpatch errors
> - check time in secs arg against max sec val
> - order header files
> - use ptr_err_or_zero macro
> - use time64 variants
> Changes v2
> - change alm to alarm
> ---
> drivers/rtc/Kconfig | 7 ++
> drivers/rtc/Makefile | 1 +
> drivers/rtc/rtc-zynqmp.c | 279 +++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 287 insertions(+)
> create mode 100644 drivers/rtc/rtc-zynqmp.c
>
> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
> index 35ea04c..bc96277 100644
> --- a/drivers/rtc/Kconfig
> +++ b/drivers/rtc/Kconfig
> @@ -1116,6 +1116,13 @@ config RTC_DRV_OPAL
> This driver can also be built as a module. If so, the module
> will be called rtc-opal.
>
> +config RTC_DRV_ZYNQMP
> + tristate "Xilinx Zynq Ultrascale+ MPSoC RTC"
> + depends on OF
> + help
> + If you say yes here you get support for the RTC controller found on
> + Xilinx Zynq Ultrascale+ MPSoC.
> +
> comment "on-CPU RTC drivers"
>
> config RTC_DRV_DAVINCI
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 2797384..e491eb5 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -159,3 +159,4 @@ obj-$(CONFIG_RTC_DRV_WM831X) += rtc-wm831x.o
> obj-$(CONFIG_RTC_DRV_WM8350) += rtc-wm8350.o
> obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o
> obj-$(CONFIG_RTC_DRV_XGENE) += rtc-xgene.o
> +obj-$(CONFIG_RTC_DRV_ZYNQMP) += rtc-zynqmp.o
> diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c
> new file mode 100644
> index 0000000..8b28762
> --- /dev/null
> +++ b/drivers/rtc/rtc-zynqmp.c
> @@ -0,0 +1,279 @@
> +/*
> + * Xilinx Zynq Ultrascale+ MPSoC Real Time Clock Driver
> + *
> + * Copyright (C) 2015 Xilinx, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + *
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/rtc.h>
> +
> +/* RTC Registers */
> +#define RTC_SET_TM_WR 0x00
> +#define RTC_SET_TM_RD 0x04
> +#define RTC_CALIB_WR 0x08
> +#define RTC_CALIB_RD 0x0C
> +#define RTC_CUR_TM 0x10
> +#define RTC_CUR_TICK 0x14
> +#define RTC_ALRM 0x18
> +#define RTC_INT_STS 0x20
> +#define RTC_INT_MASK 0x24
> +#define RTC_INT_EN 0x28
> +#define RTC_INT_DIS 0x2C
> +#define RTC_CTRL 0x40
> +
> +#define RTC_FR_EN BIT(20)
> +#define RTC_FR_DATSHIFT 16
> +#define RTC_TICK_MASK 0xFFFF
> +#define RTC_INT_SEC BIT(0)
> +#define RTC_INT_ALRM BIT(1)
> +#define RTC_OSC_EN BIT(24)
> +
> +#define RTC_CALIB_DEF 0x198233
> +#define RTC_CALIB_MASK 0x1FFFFF
> +#define RTC_SEC_MAX_VAL 0xFFFFFFFF
> +
> +struct xlnx_rtc_dev {
> + struct rtc_device *rtc;
> + void __iomem *reg_base;
> + int alarm_irq;
> + int sec_irq;
> +};
> +
> +static int xlnx_rtc_set_time(struct device *dev, struct rtc_time *tm)
> +{
> + struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
> + unsigned long new_time;
> +
> + new_time = rtc_tm_to_time64(tm);
> +
> + if (new_time > RTC_SEC_MAX_VAL)
> + return -EINVAL;
> +
> + writel(new_time, xrtcdev->reg_base + RTC_SET_TM_WR);
> +
> + return 0;
> +}
> +
> +static int xlnx_rtc_read_time(struct device *dev, struct rtc_time *tm)
> +{
> + struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
> +
> + rtc_time64_to_tm(readl(xrtcdev->reg_base + RTC_CUR_TM), tm);
> +
> + return rtc_valid_tm(tm);
> +}
> +
> +static int xlnx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> + struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
> +
> + rtc_time64_to_tm(readl(xrtcdev->reg_base + RTC_ALRM), &alrm->time);
> + alrm->enabled = readl(xrtcdev->reg_base + RTC_INT_MASK) & RTC_INT_ALRM;
> +
> + return 0;
> +}
> +
> +static int xlnx_rtc_alarm_irq_enable(struct device *dev, u32 enabled)
> +{
> + struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
> +
> + if (enabled)
> + writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_EN);
> + else
> + writel(RTC_INT_ALRM, xrtcdev->reg_base + RTC_INT_DIS);
> +
> + return 0;
> +}
> +
> +static int xlnx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> + struct xlnx_rtc_dev *xrtcdev = dev_get_drvdata(dev);
> + unsigned long alarm_time;
> +
> + alarm_time = rtc_tm_to_time64(&alrm->time);
> +
> + if (alarm_time > RTC_SEC_MAX_VAL)
> + return -EINVAL;
> +
> + writel((u32)alarm_time, (xrtcdev->reg_base + RTC_ALRM));
> +
> + xlnx_rtc_alarm_irq_enable(dev, alrm->enabled);
> +
> + return 0;
> +}
> +
> +static void xlnx_init_rtc(struct xlnx_rtc_dev *xrtcdev, u32 calibval)
> +{
> + /*
> + * Based on crystal freq of 33.330 KHz
> + * set the seconds counter and enable, set fractions counter
> + * to default value suggested as per design spec
> + * to correct RTC delay in frequency over period of time.
> + */
> + calibval &= RTC_CALIB_MASK;
> + writel(calibval, (xrtcdev->reg_base + RTC_CALIB_WR));
> +}
> +
> +static const struct rtc_class_ops xlnx_rtc_ops = {
> + .set_time = xlnx_rtc_set_time,
> + .read_time = xlnx_rtc_read_time,
> + .read_alarm = xlnx_rtc_read_alarm,
> + .set_alarm = xlnx_rtc_set_alarm,
> + .alarm_irq_enable = xlnx_rtc_alarm_irq_enable,
> +};
> +
> +static irqreturn_t xlnx_rtc_interrupt(int irq, void *id)
> +{
> + struct xlnx_rtc_dev *xrtcdev = (struct xlnx_rtc_dev *)id;
> + unsigned int status;
> +
> + status = readl(xrtcdev->reg_base + RTC_INT_STS);
> + /* Check if interrupt asserted */
> + if (!(status & (RTC_INT_SEC | RTC_INT_ALRM)))
> + return IRQ_NONE;
> +
> + /* Clear interrupt */
> + writel(status, xrtcdev->reg_base + RTC_INT_STS);
> +
> + if (status & RTC_INT_SEC)
> + rtc_update_irq(xrtcdev->rtc, 1, RTC_IRQF | RTC_UF);
> + if (status & RTC_INT_ALRM)
> + rtc_update_irq(xrtcdev->rtc, 1, RTC_IRQF | RTC_AF);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int xlnx_rtc_probe(struct platform_device *pdev)
> +{
> + struct xlnx_rtc_dev *xrtcdev;
> + struct resource *res;
> + int ret;
> + unsigned int calibvalue;
> +
> + xrtcdev = devm_kzalloc(&pdev->dev, sizeof(*xrtcdev), GFP_KERNEL);
> + if (!xrtcdev)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, xrtcdev);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
Do you want to check for return value here?
> +
> + xrtcdev->reg_base = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(xrtcdev->reg_base))
> + return PTR_ERR(xrtcdev->reg_base);
> +
> + xrtcdev->alarm_irq = platform_get_irq_byname(pdev, "alarm");
> + if (xrtcdev->alarm_irq < 0) {
> + dev_err(&pdev->dev, "no irq resource\n");
> + return xrtcdev->alarm_irq;
> + }
> + ret = devm_request_irq(&pdev->dev, xrtcdev->alarm_irq,
> + xlnx_rtc_interrupt, 0,
> + dev_name(&pdev->dev), xrtcdev);
> + if (ret) {
> + dev_err(&pdev->dev, "request irq failed\n");
> + return ret;
> + }
> +
> + xrtcdev->sec_irq = platform_get_irq_byname(pdev, "sec");
> + if (xrtcdev->sec_irq < 0) {
> + dev_err(&pdev->dev, "no irq resource\n");
> + return xrtcdev->sec_irq;
> + }
> + ret = devm_request_irq(&pdev->dev, xrtcdev->sec_irq,
> + xlnx_rtc_interrupt, 0,
> + dev_name(&pdev->dev), xrtcdev);
> + if (ret) {
> + dev_err(&pdev->dev, "request irq failed\n");
> + return ret;
> + }
> +
> + ret = of_property_read_u32(pdev->dev.of_node, "calibration",
> + &calibvalue);
> + if (ret)
> + calibvalue = RTC_CALIB_DEF;
> +
> + xlnx_init_rtc(xrtcdev, calibvalue);
> +
> + device_init_wakeup(&pdev->dev, 1);
> +
> + xrtcdev->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
> + &xlnx_rtc_ops, THIS_MODULE);
> + return PTR_ERR_OR_ZERO(xrtcdev->rtc);
> +}
> +
> +static int xlnx_rtc_remove(struct platform_device *pdev)
> +{
> + xlnx_rtc_alarm_irq_enable(&pdev->dev, 0);
> + device_init_wakeup(&pdev->dev, 0);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused xlnx_rtc_suspend(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct xlnx_rtc_dev *xrtcdev = platform_get_drvdata(pdev);
> +
> + if (device_may_wakeup(&pdev->dev))
> + enable_irq_wake(xrtcdev->alarm_irq);
> + else
> + xlnx_rtc_alarm_irq_enable(dev, 0);
> +
> + return 0;
> +}
> +
> +static int __maybe_unused xlnx_rtc_resume(struct device *dev)
> +{
> + struct platform_device *pdev = to_platform_device(dev);
> + struct xlnx_rtc_dev *xrtcdev = platform_get_drvdata(pdev);
> +
> + if (device_may_wakeup(&pdev->dev))
> + disable_irq_wake(xrtcdev->alarm_irq);
> + else
> + xlnx_rtc_alarm_irq_enable(dev, 1);
> +
> + return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(xlnx_rtc_pm_ops, xlnx_rtc_suspend, xlnx_rtc_resume);
> +
> +static const struct of_device_id xlnx_rtc_of_match[] = {
> + {.compatible = "xlnx,zynqmp-rtc" },
> + { }
> +};
> +MODULE_DEVICE_TABLE(of, xlnx_rtc_of_match);
> +
> +static struct platform_driver xlnx_rtc_driver = {
> + .probe = xlnx_rtc_probe,
> + .remove = xlnx_rtc_remove,
> + .driver = {
> + .name = KBUILD_MODNAME,
> + .pm = &xlnx_rtc_pm_ops,
> + .of_match_table = xlnx_rtc_of_match,
> + },
> +};
> +
> +module_platform_driver(xlnx_rtc_driver);
> +
> +MODULE_DESCRIPTION("Xilinx Zynq MPSoC RTC driver");
> +MODULE_AUTHOR("Xilinx Inc.");
> +MODULE_LICENSE("GPL v2");
> --
> 2.1.2
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Cheers,
Moritz
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/