Hi,
On 01/02/2016 at 15:43:22 -0700, Joshua Henderson wrote :
> This drivers adds support for the PIC32 real time clock and calendar
> peripheral:
> - reading and setting time
> - alarms when connected to an IRQ
>
> Signed-off-by: Joshua Henderson <joshua.henderson@xxxxxxxxxxxxx>
> ---
> drivers/rtc/Kconfig | 10 ++
> drivers/rtc/Makefile | 1 +
> drivers/rtc/rtc-pic32.c | 450 +++++++++++++++++++++++++++++++++++++++++++++++
Nitpick: there are multiple alignment and blank lines issues that you
can spot using checkpatch --strict.
> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
> index 62d61b2..20c9be5 100644
> --- a/drivers/rtc/Makefile
> +++ b/drivers/rtc/Makefile
> @@ -162,3 +162,4 @@ 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
> +obj-$(CONFIG_RTC_DRV_PIC32) += rtc-pic32.o
This list has to be ordered alphabetically.
> diff --git a/drivers/rtc/rtc-pic32.c b/drivers/rtc/rtc-pic32.c
> new file mode 100644
> index 0000000..7c46ccb
> --- /dev/null
> +++ b/drivers/rtc/rtc-pic32.c
> @@ -0,0 +1,450 @@
> +/*
> + * PIC32 RTC driver
> + *
> + * Joshua Henderson <joshua.henderson@xxxxxxxxxxxxx>
> + * Copyright (C) 2016 Microchip Technology Inc. All rights reserved.
> + *
> + * This program is free software; you can distribute it and/or modify it
> + * under the terms of the GNU General Public License (Version 2) as
> + * published by the Free Software Foundation.
> + *
This specify GPL v2 but you use MODULE_LICENSE("GPL")
> + * 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.
> + */
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +#include <linux/slab.h>
> +#include <linux/clk.h>
> +#include <linux/rtc.h>
> +#include <linux/bcd.h>
> +
> +#include <asm/mach-pic32/pic32.h>
> +
> +#define DRIVER_NAME "pic32-rtc"
> +
> +#define PIC32_RTCCON (0x00)
You probably don't need those parenthesis.
> +#define PIC32_RTCCON_ON BIT(15)
> +#define PIC32_RTCCON_SIDL BIT(13)
> +#define PIC32_RTCCON_RTCCLKSEL (3 << 9)
> +#define PIC32_RTCCON_RTCCLKON BIT(6)
> +#define PIC32_RTCCON_RTCWREN BIT(3)
> +#define PIC32_RTCCON_RTCSYNC BIT(2)
> +#define PIC32_RTCCON_HALFSEC BIT(1)
> +#define PIC32_RTCCON_RTCOE BIT(0)
> +
> +#define PIC32_RTCALRM (0x10)
ditto
> +#define PIC32_RTCALRM_ALRMEN BIT(15)
> +#define PIC32_RTCALRM_CHIME BIT(14)
> +#define PIC32_RTCALRM_PIV BIT(13)
> +#define PIC32_RTCALRM_ALARMSYNC BIT(12)
> +#define PIC32_RTCALRM_AMASK (0x0F << 8)
> +#define PIC32_RTCALRM_ARPT (0xFF << 0)
Nit: For those masks, you can use genmask() or directly 0x0F00 and 0xFF
> +struct pic32_rtc_dev {
> + struct rtc_device *rtc;
> + void __iomem *reg_base;
> + struct clk *clk;
> + spinlock_t flags_lock;
flags_lock is unnecessary, it is used only in one function that is
called only at probe time
> + spinlock_t alarm_lock;
> + int alarm_irq;
> + bool alarm_clk_enabled;
> +};
> +
[...]
> +static int pic32_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
> +{
> + struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
> + void __iomem *base = pdata->reg_base;
> + unsigned int have_retried = 0;
> +
> + clk_enable(pdata->clk);
> +retry_get_time:
> + rtc_tm->tm_hour = readb(base + PIC32_RTCHOUR);
> + rtc_tm->tm_min = readb(base + PIC32_RTCMIN);
> + rtc_tm->tm_mon = readb(base + PIC32_RTCMON);
> + rtc_tm->tm_mday = readb(base + PIC32_RTCDAY);
> + rtc_tm->tm_year = readb(base + PIC32_RTCYEAR);
> + rtc_tm->tm_sec = readb(base + PIC32_RTCSEC);
> +
> + /*
> + * The only way to work out whether the system was mid-update
> + * when we read it is to check the second counter, and if it
> + * is zero, then we re-try the entire read.
> + */
> +
> + if (rtc_tm->tm_sec == 0 && !have_retried) {
> + have_retried = 1;
> + goto retry_get_time;
> + }
Please change that goto in a do while loop.
> +
> + rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
> + rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
> + rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
> + rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
> + rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
> + rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
> +
> + rtc_tm->tm_year += 100;
> +
> + dev_dbg(dev, "read time %04d.%02d.%02d %02d:%02d:%02d\n",
> + 1900 + rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
> + rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec);
> +
> + rtc_tm->tm_mon -= 1;
Maybe you should do that substraction with the assignment the only
drawback is that it changes the debug output.
> +
> + clk_disable(pdata->clk);
> + return rtc_valid_tm(rtc_tm);
> +}
> +
[...]
> +static int pic32_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> + struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
> + struct rtc_time *alm_tm = &alrm->time;
> + void __iomem *base = pdata->reg_base;
> + unsigned int alm_en;
> +
> + clk_enable(pdata->clk);
> + alm_tm->tm_sec = readb(base + PIC32_ALRMSEC);
> + alm_tm->tm_min = readb(base + PIC32_ALRMMIN);
> + alm_tm->tm_hour = readb(base + PIC32_ALRMHOUR);
> + alm_tm->tm_mon = readb(base + PIC32_ALRMMON);
> + alm_tm->tm_mday = readb(base + PIC32_ALRMDAY);
> + alm_tm->tm_year = readb(base + PIC32_ALRMYEAR);
> +
> + alm_en = readb(base + PIC32_RTCALRM);
> +
> + alrm->enabled = (alm_en & PIC32_RTCALRM_ALRMEN) ? 1 : 0;
> +
> + dev_dbg(dev, "getalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
> + alm_en,
> + 1900 + alm_tm->tm_year, alm_tm->tm_mon, alm_tm->tm_mday,
> + alm_tm->tm_hour, alm_tm->tm_min, alm_tm->tm_sec);
> +
> + alm_tm->tm_sec = bcd2bin(alm_tm->tm_sec);
> + alm_tm->tm_min = bcd2bin(alm_tm->tm_min);
> + alm_tm->tm_hour = bcd2bin(alm_tm->tm_hour);
> + alm_tm->tm_mday = bcd2bin(alm_tm->tm_mday);
> + alm_tm->tm_mon = bcd2bin(alm_tm->tm_mon);
> + alm_tm->tm_mon -= 1;
You could merge both lines.
> + alm_tm->tm_year = bcd2bin(alm_tm->tm_year);
> +
> + clk_disable(pdata->clk);
> + return 0;
> +}
> +
> +static int pic32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
> +{
> + struct pic32_rtc_dev *pdata = dev_get_drvdata(dev);
> + struct rtc_time *tm = &alrm->time;
> + void __iomem *base = pdata->reg_base;
> +
> + clk_enable(pdata->clk);
> + dev_dbg(dev, "setalarm: %d, %04d.%02d.%02d %02d:%02d:%02d\n",
> + alrm->enabled,
> + 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
> + tm->tm_hour, tm->tm_min, tm->tm_sec);
> +
> + writel(0x00, base + PIC32_ALRMTIME);
> + writel(0x00, base + PIC32_ALRMDATE);
> +
> + if (tm->tm_sec < 60 && tm->tm_sec >= 0)
> + writeb(bin2bcd(tm->tm_sec), base + PIC32_ALRMSEC);
> +
> + if (tm->tm_min < 60 && tm->tm_min >= 0)
> + writeb(bin2bcd(tm->tm_min), base + PIC32_ALRMMIN);
> +
> + if (tm->tm_hour < 24 && tm->tm_hour >= 0)
> + writeb(bin2bcd(tm->tm_hour), base + PIC32_ALRMHOUR);
> +
Those three tests are unnecessary because rtc_valid_tm() is called
before ops->set_alarm.
> + pic32_rtc_setaie(dev, alrm->enabled);
> +
> + clk_disable(pdata->clk);
> + return 0;
> +}
> +
[...]
> + pic32_rtc_gettime(&pdev->dev, &rtc_tm);
> +
> + if (rtc_valid_tm(&rtc_tm)) {
> + rtc_tm.tm_year = 100;
> + rtc_tm.tm_mon = 0;
> + rtc_tm.tm_mday = 1;
> + rtc_tm.tm_hour = 0;
> + rtc_tm.tm_min = 0;
> + rtc_tm.tm_sec = 0;
> +
> + pic32_rtc_settime(NULL, &rtc_tm);
> +
> + dev_warn(&pdev->dev,
> + "warning: invalid RTC value so initializing it\n");
This is a bad idea. If you do that, userspace has no way of knowing
whether the date is valid or not.
[...]
> +static const struct of_device_id pic32_rtc_dt_ids[] = {
> + { .compatible = "microchip,pic32mzda-rtc" },
> + { /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, pic32_rtc_dt_ids);
This compatible string needs to be documented. Was that patch 1/2?
> +
> +static struct platform_driver pic32_rtc_driver = {
> + .probe = pic32_rtc_probe,
> + .remove = pic32_rtc_remove,
> + .driver = {
> + .name = DRIVER_NAME,
> + .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(pic32_rtc_dt_ids),
> + },
> +};
> +module_platform_driver(pic32_rtc_driver);
> +
> +MODULE_DESCRIPTION("Microchip PIC32 RTC Driver");
> +MODULE_AUTHOR("Joshua Henderson <joshua.henderson@xxxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:" DRIVER_NAME);
I think this driver is DT only, you can get rid of MODULE_ALIAS and
DRIVER_NAME
--
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
