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Subject[PATCH 13/26] mfd: ab8500-debugfs: Formated access AB8500 registers from debugfs entry
Date
From: carriere etienne <etienne.carriere@stericsson.com>

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: Lee Jones <lee.jones@linaro.org>
Signed-off-by: carriere etienne <etienne.carriere@stericsson.com>
Reviewed-by: Mattias WALLIN <mattias.wallin@stericsson.com>
---
drivers/mfd/ab8500-debugfs.c | 388 ++++++++++++++++++++++++++++++++++++------
1 file changed, 336 insertions(+), 52 deletions(-)

diff --git a/drivers/mfd/ab8500-debugfs.c b/drivers/mfd/ab8500-debugfs.c
index 4f36907..78a8e0c 100644
--- a/drivers/mfd/ab8500-debugfs.c
+++ b/drivers/mfd/ab8500-debugfs.c
@@ -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 +637,203 @@ 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;
+ 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;
+
+#if 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) {
+ u8 regvalue;
+ int 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 +981,10 @@ 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 +1030,20 @@ 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 __devinit ab8500_debug_probe(struct platform_device *plf)
{
+ struct dentry *file;
debug_bank = AB8500_MISC;
debug_address = AB8500_REV_REG & 0x00FF;

@@ -768,70 +1063,59 @@ static int __devinit 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;
-
- ab8500_subscribe_file =
- debugfs_create_file("irq-subscribe",
- (S_IRUGO | S_IWUGO), ab8500_dir, &plf->dev,
- &ab8500_subscribe_fops);
- if (!ab8500_subscribe_file)
- goto exit_destroy_val;
-
- ab8500_unsubscribe_file =
- debugfs_create_file("irq-unsubscribe",
- (S_IRUGO | S_IWUGO), ab8500_dir, &plf->dev,
- &ab8500_unsubscribe_fops);
- if (!ab8500_unsubscribe_file)
- goto exit_destroy_subscribe;
+ if (!file)
+ goto err;
+
+ file = debugfs_create_file("irq-subscribe",
+ (S_IRUGO | S_IWUSR), ab8500_dir, &plf->dev,
+ &ab8500_subscribe_fops);
+ if (!file)
+ goto err;
+
+ file = debugfs_create_file("irq-unsubscribe",
+ (S_IRUGO | S_IWUSR), ab8500_dir, &plf->dev,
+ &ab8500_unsubscribe_fops);
+ 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 __devexit 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;
}

--
1.7.9.5


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