diff options
author | Suneel Garapati <suneel.garapati@xilinx.com> | 2015-08-19 15:23:22 +0530 |
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committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2015-09-05 19:37:19 +0200 |
commit | 11143c19eb57a8aee4335e57b21f2897b9fff294 (patch) | |
tree | 60d34bea0ab1b40ce127db24dd726abc71be6196 /drivers/rtc/rtc-zynqmp.c | |
parent | 12ece40d9196e01961192fc25cfdaf22392520de (diff) | |
download | linux-11143c19eb57a8aee4335e57b21f2897b9fff294.tar.bz2 |
rtc: add xilinx zynqmp rtc driver
Add support for RTC controller found on Xilinx Zynq Ultrascale+ MPSoC
platform.
Signed-off-by: Suneel Garapati <suneel.garapati@xilinx.com>
Acked-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc/rtc-zynqmp.c')
-rw-r--r-- | drivers/rtc/rtc-zynqmp.c | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-zynqmp.c b/drivers/rtc/rtc-zynqmp.c new file mode 100644 index 000000000000..8b28762f06df --- /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); + + 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"); |