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 <[email protected]> > --- > 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 <[email protected]> > + * 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 <[email protected]>"); > +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
