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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
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+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;
}