Re: [PATCH] Input: hp_sdc_rtc - remove dead chardev code

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

On 23/10/2019 16:25:02+0200, Arnd Bergmann wrote:
> The driver contains half of the implementation of /dev/rtc, but this
> was never completed, and it is now incompatible with the drivers/rtc
> framework.
> 
> Remove the chardev completely. If anyone wants to add the functionality
> later, that shoudl be done through rtc_register_device().
> 
> The remaining portions of the driver basically implement a single
> procfs file that may or may not be used anywhere. Not sure why this
> is in drivers/input/ though.
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

> ---
>  drivers/input/misc/hp_sdc_rtc.c | 342 --------------------------------
>  1 file changed, 342 deletions(-)
> 
> diff --git a/drivers/input/misc/hp_sdc_rtc.c b/drivers/input/misc/hp_sdc_rtc.c
> index abca895a6156..199bc17ddb1d 100644
> --- a/drivers/input/misc/hp_sdc_rtc.c
> +++ b/drivers/input/misc/hp_sdc_rtc.c
> @@ -53,28 +53,10 @@ MODULE_LICENSE("Dual BSD/GPL");
>  
>  #define RTC_VERSION "1.10d"
>  
> -static DEFINE_MUTEX(hp_sdc_rtc_mutex);
>  static unsigned long epoch = 2000;
>  
>  static struct semaphore i8042tregs;
>  
> -static hp_sdc_irqhook hp_sdc_rtc_isr;
> -
> -static struct fasync_struct *hp_sdc_rtc_async_queue;
> -
> -static DECLARE_WAIT_QUEUE_HEAD(hp_sdc_rtc_wait);
> -
> -static ssize_t hp_sdc_rtc_read(struct file *file, char __user *buf,
> -			       size_t count, loff_t *ppos);
> -
> -static long hp_sdc_rtc_unlocked_ioctl(struct file *file,
> -				      unsigned int cmd, unsigned long arg);
> -
> -static unsigned int hp_sdc_rtc_poll(struct file *file, poll_table *wait);
> -
> -static int hp_sdc_rtc_open(struct inode *inode, struct file *file);
> -static int hp_sdc_rtc_fasync (int fd, struct file *filp, int on);
> -
>  static void hp_sdc_rtc_isr (int irq, void *dev_id, 
>  			    uint8_t status, uint8_t data) 
>  {
> @@ -283,151 +265,6 @@ static inline int hp_sdc_rtc_read_ct(struct timespec64 *res) {
>  	return 0;
>  }
>  
> -
> -#if 0 /* not used yet */
> -/* Set the i8042 real-time clock */
> -static int hp_sdc_rtc_set_rt (struct timeval *setto)
> -{
> -	uint32_t tenms;
> -	unsigned int days;
> -	hp_sdc_transaction t;
> -	uint8_t tseq[11] = {
> -		HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT,
> -		HP_SDC_CMD_SET_RTMS, 3, 0, 0, 0,
> -		HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT,
> -		HP_SDC_CMD_SET_RTD, 2, 0, 0 
> -	};
> -
> -	t.endidx = 10;
> -
> -	if (0xffff < setto->tv_sec / 86400) return -1;
> -	days = setto->tv_sec / 86400;
> -	if (0xffff < setto->tv_usec / 1000000 / 86400) return -1;
> -	days += ((setto->tv_sec % 86400) + setto->tv_usec / 1000000) / 86400;
> -	if (days > 0xffff) return -1;
> -
> -	if (0xffffff < setto->tv_sec) return -1;
> -	tenms  = setto->tv_sec * 100;
> -	if (0xffffff < setto->tv_usec / 10000) return -1;
> -	tenms += setto->tv_usec / 10000;
> -	if (tenms > 0xffffff) return -1;
> -
> -	tseq[3] = (uint8_t)(tenms & 0xff);
> -	tseq[4] = (uint8_t)((tenms >> 8)  & 0xff);
> -	tseq[5] = (uint8_t)((tenms >> 16) & 0xff);
> -
> -	tseq[9] = (uint8_t)(days & 0xff);
> -	tseq[10] = (uint8_t)((days >> 8) & 0xff);
> -
> -	t.seq =	tseq;
> -
> -	if (hp_sdc_enqueue_transaction(&t)) return -1;
> -	return 0;
> -}
> -
> -/* Set the i8042 fast handshake timer */
> -static int hp_sdc_rtc_set_fhs (struct timeval *setto)
> -{
> -	uint32_t tenms;
> -	hp_sdc_transaction t;
> -	uint8_t tseq[5] = {
> -		HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT,
> -		HP_SDC_CMD_SET_FHS, 2, 0, 0
> -	};
> -
> -	t.endidx = 4;
> -
> -	if (0xffff < setto->tv_sec) return -1;
> -	tenms  = setto->tv_sec * 100;
> -	if (0xffff < setto->tv_usec / 10000) return -1;
> -	tenms += setto->tv_usec / 10000;
> -	if (tenms > 0xffff) return -1;
> -
> -	tseq[3] = (uint8_t)(tenms & 0xff);
> -	tseq[4] = (uint8_t)((tenms >> 8)  & 0xff);
> -
> -	t.seq =	tseq;
> -
> -	if (hp_sdc_enqueue_transaction(&t)) return -1;
> -	return 0;
> -}
> -
> -
> -/* Set the i8042 match timer (a.k.a. alarm) */
> -#define hp_sdc_rtc_set_mt (setto) \
> -	hp_sdc_rtc_set_i8042timer(setto, HP_SDC_CMD_SET_MT)
> -
> -/* Set the i8042 delay timer */
> -#define hp_sdc_rtc_set_dt (setto) \
> -	hp_sdc_rtc_set_i8042timer(setto, HP_SDC_CMD_SET_DT)
> -
> -/* Set the i8042 cycle timer (a.k.a. periodic) */
> -#define hp_sdc_rtc_set_ct (setto) \
> -	hp_sdc_rtc_set_i8042timer(setto, HP_SDC_CMD_SET_CT)
> -
> -/* Set one of the i8042 3-byte wide timers */
> -static int hp_sdc_rtc_set_i8042timer (struct timeval *setto, uint8_t setcmd)
> -{
> -	uint32_t tenms;
> -	hp_sdc_transaction t;
> -	uint8_t tseq[6] = {
> -		HP_SDC_ACT_PRECMD | HP_SDC_ACT_DATAOUT,
> -		0, 3, 0, 0, 0
> -	};
> -
> -	t.endidx = 6;
> -
> -	if (0xffffff < setto->tv_sec) return -1;
> -	tenms  = setto->tv_sec * 100;
> -	if (0xffffff < setto->tv_usec / 10000) return -1;
> -	tenms += setto->tv_usec / 10000;
> -	if (tenms > 0xffffff) return -1;
> -
> -	tseq[1] = setcmd;
> -	tseq[3] = (uint8_t)(tenms & 0xff);
> -	tseq[4] = (uint8_t)((tenms >> 8)  & 0xff);
> -	tseq[5] = (uint8_t)((tenms >> 16)  & 0xff);
> -
> -	t.seq =			tseq;
> -
> -	if (hp_sdc_enqueue_transaction(&t)) { 
> -		return -1;
> -	}
> -	return 0;
> -}
> -#endif
> -
> -static ssize_t hp_sdc_rtc_read(struct file *file, char __user *buf,
> -			       size_t count, loff_t *ppos) {
> -	ssize_t retval;
> -
> -        if (count < sizeof(unsigned long))
> -                return -EINVAL;
> -
> -	retval = put_user(68, (unsigned long __user *)buf);
> -	return retval;
> -}
> -
> -static __poll_t hp_sdc_rtc_poll(struct file *file, poll_table *wait)
> -{
> -        unsigned long l;
> -
> -	l = 0;
> -        if (l != 0)
> -                return EPOLLIN | EPOLLRDNORM;
> -        return 0;
> -}
> -
> -static int hp_sdc_rtc_open(struct inode *inode, struct file *file)
> -{
> -        return 0;
> -}
> -
> -static int hp_sdc_rtc_fasync (int fd, struct file *filp, int on)
> -{
> -        return fasync_helper (fd, filp, on, &hp_sdc_rtc_async_queue);
> -}
> -
>  static int hp_sdc_rtc_proc_show(struct seq_file *m, void *v)
>  {
>  #define YN(bit) ("no")
> @@ -507,182 +344,6 @@ static int hp_sdc_rtc_proc_show(struct seq_file *m, void *v)
>  #undef NY
>  }
>  
> -static int hp_sdc_rtc_ioctl(struct file *file, 
> -			    unsigned int cmd, unsigned long arg)
> -{
> -#if 1
> -	return -EINVAL;
> -#else
> -	
> -        struct rtc_time wtime; 
> -	struct timeval ttime;
> -	int use_wtime = 0;
> -
> -	/* This needs major work. */
> -
> -        switch (cmd) {
> -
> -        case RTC_AIE_OFF:       /* Mask alarm int. enab. bit    */
> -        case RTC_AIE_ON:        /* Allow alarm interrupts.      */
> -	case RTC_PIE_OFF:       /* Mask periodic int. enab. bit */
> -        case RTC_PIE_ON:        /* Allow periodic ints          */
> -        case RTC_UIE_ON:        /* Allow ints for RTC updates.  */
> -        case RTC_UIE_OFF:       /* Allow ints for RTC updates.  */
> -        {
> -		/* We cannot mask individual user timers and we
> -		   cannot tell them apart when they occur, so it 
> -		   would be disingenuous to succeed these IOCTLs */
> -		return -EINVAL;
> -        }
> -        case RTC_ALM_READ:      /* Read the present alarm time */
> -        {
> -		if (hp_sdc_rtc_read_mt(&ttime)) return -EFAULT;
> -		if (hp_sdc_rtc_read_bbrtc(&wtime)) return -EFAULT;
> -
> -		wtime.tm_hour = ttime.tv_sec / 3600;  ttime.tv_sec %= 3600;
> -		wtime.tm_min  = ttime.tv_sec / 60;    ttime.tv_sec %= 60;
> -		wtime.tm_sec  = ttime.tv_sec;
> -                
> -		break;
> -        }
> -        case RTC_IRQP_READ:     /* Read the periodic IRQ rate.  */
> -        {
> -                return put_user(hp_sdc_rtc_freq, (unsigned long *)arg);
> -        }
> -        case RTC_IRQP_SET:      /* Set periodic IRQ rate.       */
> -        {
> -                /* 
> -                 * The max we can do is 100Hz.
> -		 */
> -
> -                if ((arg < 1) || (arg > 100)) return -EINVAL;
> -		ttime.tv_sec = 0;
> -		ttime.tv_usec = 1000000 / arg;
> -		if (hp_sdc_rtc_set_ct(&ttime)) return -EFAULT;
> -		hp_sdc_rtc_freq = arg;
> -                return 0;
> -        }
> -        case RTC_ALM_SET:       /* Store a time into the alarm */
> -        {
> -                /*
> -                 * This expects a struct hp_sdc_rtc_time. Writing 0xff means
> -                 * "don't care" or "match all" for PC timers.  The HP SDC
> -		 * does not support that perk, but it could be emulated fairly
> -		 * easily.  Only the tm_hour, tm_min and tm_sec are used.
> -		 * We could do it with 10ms accuracy with the HP SDC, if the 
> -		 * rtc interface left us a way to do that.
> -                 */
> -                struct hp_sdc_rtc_time alm_tm;
> -
> -                if (copy_from_user(&alm_tm, (struct hp_sdc_rtc_time*)arg,
> -                                   sizeof(struct hp_sdc_rtc_time)))
> -                       return -EFAULT;
> -
> -                if (alm_tm.tm_hour > 23) return -EINVAL;
> -		if (alm_tm.tm_min  > 59) return -EINVAL;
> -		if (alm_tm.tm_sec  > 59) return -EINVAL;  
> -
> -		ttime.sec = alm_tm.tm_hour * 3600 + 
> -		  alm_tm.tm_min * 60 + alm_tm.tm_sec;
> -		ttime.usec = 0;
> -		if (hp_sdc_rtc_set_mt(&ttime)) return -EFAULT;
> -                return 0;
> -        }
> -        case RTC_RD_TIME:       /* Read the time/date from RTC  */
> -        {
> -		if (hp_sdc_rtc_read_bbrtc(&wtime)) return -EFAULT;
> -                break;
> -        }
> -        case RTC_SET_TIME:      /* Set the RTC */
> -        {
> -                struct rtc_time hp_sdc_rtc_tm;
> -                unsigned char mon, day, hrs, min, sec, leap_yr;
> -                unsigned int yrs;
> -
> -                if (!capable(CAP_SYS_TIME))
> -                        return -EACCES;
> -		if (copy_from_user(&hp_sdc_rtc_tm, (struct rtc_time *)arg,
> -                                   sizeof(struct rtc_time)))
> -                        return -EFAULT;
> -
> -                yrs = hp_sdc_rtc_tm.tm_year + 1900;
> -                mon = hp_sdc_rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
> -                day = hp_sdc_rtc_tm.tm_mday;
> -                hrs = hp_sdc_rtc_tm.tm_hour;
> -                min = hp_sdc_rtc_tm.tm_min;
> -                sec = hp_sdc_rtc_tm.tm_sec;
> -
> -                if (yrs < 1970)
> -                        return -EINVAL;
> -
> -                leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
> -
> -                if ((mon > 12) || (day == 0))
> -                        return -EINVAL;
> -                if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
> -                        return -EINVAL;
> -		if ((hrs >= 24) || (min >= 60) || (sec >= 60))
> -                        return -EINVAL;
> -
> -                if ((yrs -= eH) > 255)    /* They are unsigned */
> -                        return -EINVAL;
> -
> -
> -                return 0;
> -        }
> -        case RTC_EPOCH_READ:    /* Read the epoch.      */
> -        {
> -                return put_user (epoch, (unsigned long *)arg);
> -        }
> -        case RTC_EPOCH_SET:     /* Set the epoch.       */
> -        {
> -                /* 
> -                 * There were no RTC clocks before 1900.
> -                 */
> -                if (arg < 1900)
> -		  return -EINVAL;
> -		if (!capable(CAP_SYS_TIME))
> -		  return -EACCES;
> -		
> -                epoch = arg;
> -                return 0;
> -        }
> -        default:
> -                return -EINVAL;
> -        }
> -        return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
> -#endif
> -}
> -
> -static long hp_sdc_rtc_unlocked_ioctl(struct file *file,
> -				      unsigned int cmd, unsigned long arg)
> -{
> -	int ret;
> -
> -	mutex_lock(&hp_sdc_rtc_mutex);
> -	ret = hp_sdc_rtc_ioctl(file, cmd, arg);
> -	mutex_unlock(&hp_sdc_rtc_mutex);
> -
> -	return ret;
> -}
> -
> -
> -static const struct file_operations hp_sdc_rtc_fops = {
> -        .owner =		THIS_MODULE,
> -        .llseek =		no_llseek,
> -        .read =			hp_sdc_rtc_read,
> -        .poll =			hp_sdc_rtc_poll,
> -        .unlocked_ioctl =	hp_sdc_rtc_unlocked_ioctl,
> -        .open =			hp_sdc_rtc_open,
> -        .fasync =		hp_sdc_rtc_fasync,
> -};
> -
> -static struct miscdevice hp_sdc_rtc_dev = {
> -        .minor =	RTC_MINOR,
> -        .name =		"rtc_HIL",
> -        .fops =		&hp_sdc_rtc_fops
> -};
> -
>  static int __init hp_sdc_rtc_init(void)
>  {
>  	int ret;
> @@ -696,8 +357,6 @@ static int __init hp_sdc_rtc_init(void)
>  
>  	if ((ret = hp_sdc_request_timer_irq(&hp_sdc_rtc_isr)))
>  		return ret;
> -	if (misc_register(&hp_sdc_rtc_dev) != 0)
> -		printk(KERN_INFO "Could not register misc. dev for i8042 rtc\n");
>  
>          proc_create_single("driver/rtc", 0, NULL, hp_sdc_rtc_proc_show);
>  
> @@ -710,7 +369,6 @@ static int __init hp_sdc_rtc_init(void)
>  static void __exit hp_sdc_rtc_exit(void)
>  {
>  	remove_proc_entry ("driver/rtc", NULL);
> -        misc_deregister(&hp_sdc_rtc_dev);
>  	hp_sdc_release_timer_irq(hp_sdc_rtc_isr);
>          printk(KERN_INFO "HP i8042 SDC + MSM-58321 RTC support unloaded\n");
>  }
> -- 
> 2.20.0
> 

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com