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Commit 0fbce76e authored by carriere etienne's avatar carriere etienne Committed by Lee Jones
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mfd: ab8500-debugfs: Formated access AB8500 registers from debugfs entry 



Add debugfs entry ab8500/hwreg to read/write bit-field in AB8500 registers.
Check the debugfs entries usage from heading comments in ab8500-debugfs.c

Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
Signed-off-by: default avatarcarriere etienne <etienne.carriere@stericsson.com>
Reviewed-by: default avatarMattias WALLIN <mattias.wallin@stericsson.com>
parent fad55a86

drivers/mfd/ab8500-debugfs.c

+338 −52
Original line number Diff line number Diff line
@@ -4,6 +4,72 @@ 
 * Author: Mattias Wallin <mattias.wallin@stericsson.com> for ST-Ericsson.

 * License Terms: GNU General Public License v2

 */

/*

 * AB8500 register access

 * ======================

 *

 * read:

 * # echo BANK  >  <debugfs>/ab8500/register-bank

 * # echo ADDR  >  <debugfs>/ab8500/register-address

 * # cat <debugfs>/ab8500/register-value

 *

 * write:

 * # echo BANK  >  <debugfs>/ab8500/register-bank

 * # echo ADDR  >  <debugfs>/ab8500/register-address

 * # echo VALUE >  <debugfs>/ab8500/register-value

 *

 * read all registers from a bank:

 * # echo BANK  >  <debugfs>/ab8500/register-bank

 * # cat <debugfs>/ab8500/all-bank-register

 *

 * BANK   target AB8500 register bank

 * ADDR   target AB8500 register address

 * VALUE  decimal or 0x-prefixed hexadecimal

 *

 *

 * User Space notification on AB8500 IRQ

 * =====================================

 *

 * Allows user space entity to be notified when target AB8500 IRQ occurs.

 * When subscribed, a sysfs entry is created in ab8500.i2c platform device.

 * One can pool this file to get target IRQ occurence information.

 *

 * subscribe to an AB8500 IRQ:

 * # echo IRQ  >  <debugfs>/ab8500/irq-subscribe

 *

 * unsubscribe from an AB8500 IRQ:

 * # echo IRQ  >  <debugfs>/ab8500/irq-unsubscribe

 *

 *

 * AB8500 register formated read/write access

 * ==========================================

 *

 * Read:  read data, data>>SHIFT, data&=MASK, output data

 *        [0xABCDEF98] shift=12 mask=0xFFF => 0x00000CDE

 * Write: read data, data &= ~(MASK<<SHIFT), data |= (VALUE<<SHIFT), write data

 *        [0xABCDEF98] shift=12 mask=0xFFF value=0x123 => [0xAB123F98]

 *

 * Usage:

 * # echo "CMD [OPTIONS] BANK ADRESS [VALUE]" > $debugfs/ab8500/hwreg

 *

 * CMD      read      read access

 *          write     write access

 *

 * BANK     target reg bank

 * ADDRESS  target reg address

 * VALUE    (write) value to be updated

 *

 * OPTIONS

 *  -d|-dec            (read) output in decimal

 *  -h|-hexa           (read) output in 0x-hexa (default)

 *  -l|-w|-b           32bit (default), 16bit or 8bit reg access

 *  -m|-mask MASK      0x-hexa mask (default 0xFFFFFFFF)

 *  -s|-shift SHIFT    bit shift value (read:left, write:right)

 *  -o|-offset OFFSET  address offset to add to ADDRESS value

 *

 * Warning: bit shift operation is applied to bit-mask.

 * Warning: bit shift direction depends on read or right command.

 */



#include <linux/seq_file.h>

#include <linux/uaccess.h>
@@ -18,6 +84,11 @@ 
#include <linux/mfd/abx500.h>

#include <linux/mfd/abx500/ab8500.h>



#ifdef CONFIG_DEBUG_FS

#include <linux/string.h>

#include <linux/ctype.h>

#endif



static u32 debug_bank;

static u32 debug_address;
@@ -52,6 +123,25 @@ struct ab8500_prcmu_ranges { 
	const struct ab8500_reg_range *range;

};



/* hwreg- "mask" and "shift" entries ressources */

struct hwreg_cfg {

	u32  bank;      /* target bank */

	u32  addr;      /* target address */

	uint fmt;       /* format */

	uint mask;      /* read/write mask, applied before any bit shift */

	int  shift;     /* bit shift (read:right shift, write:left shift */

};

/* fmt bit #0: 0=hexa, 1=dec */

#define REG_FMT_DEC(c) ((c)->fmt & 0x1)

#define REG_FMT_HEX(c) (!REG_FMT_DEC(c))



static struct hwreg_cfg hwreg_cfg = {

	.addr = 0,			/* default: invalid phys addr */

	.fmt = 0,			/* default: 32bit access, hex output */

	.mask = 0xFFFFFFFF,	/* default: no mask */

	.shift = 0,			/* default: no bit shift */

};



#define AB8500_NAME_STRING "ab8500"

#define AB8500_NUM_BANKS 22
@@ -547,6 +637,205 @@ static ssize_t ab8500_val_write(struct file *file, 
	return count;

}



/*

 * - HWREG DB8500 formated routines

 */

static int ab8500_hwreg_print(struct seq_file *s, void *d)

{

	struct device *dev = s->private;

	int ret;

	u8 regvalue;



	ret = abx500_get_register_interruptible(dev,

		(u8)hwreg_cfg.bank, (u8)hwreg_cfg.addr, &regvalue);

	if (ret < 0) {

		dev_err(dev, "abx500_get_reg fail %d, %d\n",

			ret, __LINE__);

		return -EINVAL;

	}



	if (hwreg_cfg.shift >= 0)

		regvalue >>= hwreg_cfg.shift;

	else

		regvalue <<= -hwreg_cfg.shift;

	regvalue &= hwreg_cfg.mask;



	if (REG_FMT_DEC(&hwreg_cfg))

		seq_printf(s, "%d\n", regvalue);

	else

		seq_printf(s, "0x%02X\n", regvalue);

	return 0;

}



static int ab8500_hwreg_open(struct inode *inode, struct file *file)

{

	return single_open(file, ab8500_hwreg_print, inode->i_private);

}



/*

 * return length of an ASCII numerical value, 0 is string is not a

 * numerical value.

 * string shall start at value 1st char.

 * string can be tailed with \0 or space or newline chars only.

 * value can be decimal or hexadecimal (prefixed 0x or 0X).

 */

static int strval_len(char *b)

{

	char *s = b;

	if ((*s == '0') && ((*(s+1) == 'x') || (*(s+1) == 'X'))) {

		s += 2;

		for (; *s && (*s != ' ') && (*s != '\n'); s++) {

			if (!isxdigit(*s))

				return 0;

		}

	} else {

		if (*s == '-')

			s++;

		for (; *s && (*s != ' ') && (*s != '\n'); s++) {

			if (!isdigit(*s))

				return 0;

		}

	}

	return (int) (s-b);

}



/*

 * parse hwreg input data.

 * update global hwreg_cfg only if input data syntax is ok.

 */

static ssize_t hwreg_common_write(char *b, struct hwreg_cfg *cfg,

		struct device *dev)

{

	uint write, val = 0;

	u8  regvalue;

	int ret;

	struct hwreg_cfg loc = {

		.bank = 0,          /* default: invalid phys addr */

		.addr = 0,          /* default: invalid phys addr */

		.fmt = 0,           /* default: 32bit access, hex output */

		.mask = 0xFFFFFFFF, /* default: no mask */

		.shift = 0,         /* default: no bit shift */

	};



	/* read or write ? */

	if (!strncmp(b, "read ", 5)) {

		write = 0;

		b += 5;

	} else if (!strncmp(b, "write ", 6)) {

		write = 1;

		b += 6;

	} else

		return -EINVAL;



	/* OPTIONS -l|-w|-b -s -m -o */

	while ((*b == ' ') || (*b == '-')) {

		if (*(b-1) != ' ') {

			b++;

			continue;

		}

		if ((!strncmp(b, "-d ", 3)) ||

				(!strncmp(b, "-dec ", 5))) {

			b += (*(b+2) == ' ') ? 3 : 5;

			loc.fmt |= (1<<0);

		} else if ((!strncmp(b, "-h ", 3)) ||

				(!strncmp(b, "-hex ", 5))) {

			b += (*(b+2) == ' ') ? 3 : 5;

			loc.fmt &= ~(1<<0);

		} else if ((!strncmp(b, "-m ", 3)) ||

				(!strncmp(b, "-mask ", 6))) {

			b += (*(b+2) == ' ') ? 3 : 6;

			if (strval_len(b) == 0)

				return -EINVAL;

			loc.mask = simple_strtoul(b, &b, 0);

		} else if ((!strncmp(b, "-s ", 3)) ||

				(!strncmp(b, "-shift ", 7))) {

			b += (*(b+2) == ' ') ? 3 : 7;

			if (strval_len(b) == 0)

				return -EINVAL;

			loc.shift = simple_strtol(b, &b, 0);

		} else {

			return -EINVAL;

		}

	}

	/* get arg BANK and ADDRESS */

	if (strval_len(b) == 0)

		return -EINVAL;

	loc.bank = simple_strtoul(b, &b, 0);

	while (*b == ' ')

		b++;

	if (strval_len(b) == 0)

		return -EINVAL;

	loc.addr = simple_strtoul(b, &b, 0);



	if (write) {

		while (*b == ' ')

			b++;

		if (strval_len(b) == 0)

			return -EINVAL;

		val = simple_strtoul(b, &b, 0);

	}



	/* args are ok, update target cfg (mainly for read) */

	*cfg = loc;



#ifdef ABB_HWREG_DEBUG

	pr_warn("HWREG request: %s, %s, addr=0x%08X, mask=0x%X, shift=%d"

			"value=0x%X\n", (write) ? "write" : "read",

			REG_FMT_DEC(cfg) ? "decimal" : "hexa",

			cfg->addr, cfg->mask, cfg->shift, val);

#endif



	if (!write)

		return 0;



	ret = abx500_get_register_interruptible(dev,

			(u8)cfg->bank, (u8)cfg->addr, &regvalue);

	if (ret < 0) {

		dev_err(dev, "abx500_get_reg fail %d, %d\n",

			ret, __LINE__);

		return -EINVAL;

	}



	if (cfg->shift >= 0) {

		regvalue &= ~(cfg->mask << (cfg->shift));

		val = (val & cfg->mask) << (cfg->shift);

	} else {

		regvalue &= ~(cfg->mask >> (-cfg->shift));

		val = (val & cfg->mask) >> (-cfg->shift);

	}

	val = val | regvalue;



	ret = abx500_set_register_interruptible(dev,

			(u8)cfg->bank, (u8)cfg->addr, (u8)val);

	if (ret < 0) {

		pr_err("abx500_set_reg failed %d, %d", ret, __LINE__);

		return -EINVAL;

	}



	return 0;

}



static ssize_t ab8500_hwreg_write(struct file *file,

	const char __user *user_buf, size_t count, loff_t *ppos)

{

	struct device *dev = ((struct seq_file *)(file->private_data))->private;

	char buf[128];

	int buf_size, ret;



	/* Get userspace string and assure termination */

	buf_size = min(count, (sizeof(buf)-1));

	if (copy_from_user(buf, user_buf, buf_size))

		return -EFAULT;

	buf[buf_size] = 0;



	/* get args and process */

	ret = hwreg_common_write(buf, &hwreg_cfg, dev);

	return (ret) ? ret : buf_size;

}



/*

 * - irq subscribe/unsubscribe stuff

 */

static int ab8500_subscribe_unsubscribe_print(struct seq_file *s, void *p)

{

	seq_printf(s, "%d\n", irq_first);
@@ -694,6 +983,10 @@ static ssize_t ab8500_unsubscribe_write(struct file *file, 
	return buf_size;

}



/*

 * - several deubgfs nodes fops

 */



static const struct file_operations ab8500_bank_fops = {

	.open = ab8500_bank_open,

	.write = ab8500_bank_write,
@@ -739,16 +1032,20 @@ static const struct file_operations ab8500_unsubscribe_fops = { 
	.owner = THIS_MODULE,

};



static const struct file_operations ab8500_hwreg_fops = {

	.open = ab8500_hwreg_open,

	.write = ab8500_hwreg_write,

	.read = seq_read,

	.llseek = seq_lseek,

	.release = single_release,

	.owner = THIS_MODULE,

};



static struct dentry *ab8500_dir;

static struct dentry *ab8500_reg_file;

static struct dentry *ab8500_bank_file;

static struct dentry *ab8500_address_file;

static struct dentry *ab8500_val_file;

static struct dentry *ab8500_subscribe_file;

static struct dentry *ab8500_unsubscribe_file;



static int ab8500_debug_probe(struct platform_device *plf)

{

	struct dentry *file;

	debug_bank = AB8500_MISC;

	debug_address = AB8500_REV_REG & 0x00FF;
@@ -768,70 +1065,59 @@ static int ab8500_debug_probe(struct platform_device *plf) 


	ab8500_dir = debugfs_create_dir(AB8500_NAME_STRING, NULL);

	if (!ab8500_dir)

		goto exit_no_debugfs;

		goto err;



	ab8500_reg_file = debugfs_create_file("all-bank-registers",

	file = debugfs_create_file("all-bank-registers",

		S_IRUGO, ab8500_dir, &plf->dev, &ab8500_registers_fops);

	if (!ab8500_reg_file)

		goto exit_destroy_dir;

	if (!file)

		goto err;



	ab8500_bank_file = debugfs_create_file("register-bank",

	file = debugfs_create_file("register-bank",

		(S_IRUGO | S_IWUSR), ab8500_dir, &plf->dev, &ab8500_bank_fops);

	if (!ab8500_bank_file)

		goto exit_destroy_reg;

	if (!file)

		goto err;



	ab8500_address_file = debugfs_create_file("register-address",

	file = debugfs_create_file("register-address",

		(S_IRUGO | S_IWUSR), ab8500_dir, &plf->dev,

		&ab8500_address_fops);

	if (!ab8500_address_file)

		goto exit_destroy_bank;

	if (!file)

		goto err;



	ab8500_val_file = debugfs_create_file("register-value",

	file = debugfs_create_file("register-value",

		(S_IRUGO | S_IWUSR), ab8500_dir, &plf->dev, &ab8500_val_fops);

	if (!ab8500_val_file)

		goto exit_destroy_address;

	if (!file)

		goto err;



	ab8500_subscribe_file =

		debugfs_create_file("irq-subscribe",

				    (S_IRUGO | S_IWUGO), ab8500_dir, &plf->dev,

	file = debugfs_create_file("irq-subscribe",

		(S_IRUGO | S_IWUSR), ab8500_dir, &plf->dev,

		&ab8500_subscribe_fops);

	if (!ab8500_subscribe_file)

		goto exit_destroy_val;

	if (!file)

		goto err;



	ab8500_unsubscribe_file =

		debugfs_create_file("irq-unsubscribe",

				    (S_IRUGO | S_IWUGO), ab8500_dir, &plf->dev,

	file = debugfs_create_file("irq-unsubscribe",

		(S_IRUGO | S_IWUSR), ab8500_dir, &plf->dev,

		&ab8500_unsubscribe_fops);

	if (!ab8500_unsubscribe_file)

		goto exit_destroy_subscribe;

	if (!file)

		goto err;



	file = debugfs_create_file("hwreg",

		(S_IRUGO | S_IWUSR), ab8500_dir, &plf->dev,

		&ab8500_hwreg_fops);

	if (!file)

		goto err;



	return 0;



exit_destroy_subscribe:

	debugfs_remove(ab8500_subscribe_file);

exit_destroy_val:

	debugfs_remove(ab8500_val_file);

exit_destroy_address:

	debugfs_remove(ab8500_address_file);

exit_destroy_bank:

	debugfs_remove(ab8500_bank_file);

exit_destroy_reg:

	debugfs_remove(ab8500_reg_file);

exit_destroy_dir:

	debugfs_remove(ab8500_dir);

exit_no_debugfs:

err:

	if (ab8500_dir)

		debugfs_remove_recursive(ab8500_dir);

	dev_err(&plf->dev, "failed to create debugfs entries.\n");

	return -ENOMEM;

}



static int ab8500_debug_remove(struct platform_device *plf)

{

	debugfs_remove(ab8500_val_file);

	debugfs_remove(ab8500_address_file);

	debugfs_remove(ab8500_bank_file);

	debugfs_remove(ab8500_reg_file);

	debugfs_remove(ab8500_dir);



	debugfs_remove_recursive(ab8500_dir);

	return 0;

}