[PATCH 2/9] omap: mux: Add new style pin multiplexing code for omap3

[PATCH 2/9] omap: mux: Add new style pin multiplexing code for omap3

[Tony Lindgren]

Initially only for 34xx. This code allows us to:

- Make the code more generic as the omap internal signal
  names can stay the same across omap generations for some
  devices

- Map mux registers to GPIO registers that is needed for
  dynamic muxing of pins during off-idle

- Override bootloader mux values via kernel cmdline using
  omap_mux=some.signa1=0x1234,some.signal2=0x1234

- View and set the mux registers via debugfs if
  CONFIG_DEBUG_FS is enabled

Cc: Mike Rapoport <mike@compulab.co.il>
Cc: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 Documentation/kernel-parameters.txt |    5 
 arch/arm/mach-omap2/mux.c           |  444 +++++++++++++++++++++++++++++++++++
 arch/arm/mach-omap2/mux.h           |  160 +++++++++++++
 arch/arm/plat-omap/mux.c            |    8 -
 4 files changed, 611 insertions(+), 6 deletions(-)
 create mode 100644 arch/arm/mach-omap2/mux.h

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9107b38..24a0d84 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1772,6 +1772,11 @@ and is between 256 and 4096 characters. It is defined in the file
 			waiting for the ACK, so if this is set too high
 			interrupts *may* be lost!
 
+	omap_mux=	[OMAP] Override bootloader pin multiplexing.
+			Format: <mux_mode0.mode_name=value>...
+			For example, to override I2C bus2:
+			omap_mux=i2c2_scl.i2c2_scl=0x100,i2c2_sda.i2c2_sda=0x100
+
 	opl3=		[HW,OSS]
 			Format: <io>
 
diff --git a/arch/arm/mach-omap2/mux.c b/arch/arm/mach-omap2/mux.c
index 64250c5..b082b50 100644
--- a/arch/arm/mach-omap2/mux.c
+++ b/arch/arm/mach-omap2/mux.c
@@ -27,18 +27,23 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/spinlock.h>
+#include <linux/list.h>
 
 #include <asm/system.h>
 
 #include <plat/control.h>
 #include <plat/mux.h>
 
-#ifdef CONFIG_OMAP_MUX
+#include "mux.h"
 
 #define OMAP_MUX_BASE_OFFSET		0x30	/* Offset from CTRL_BASE */
 #define OMAP_MUX_BASE_SZ		0x5ca
 
-static struct omap_mux_cfg arch_mux_cfg;
+struct omap_mux_entry {
+	struct omap_mux		mux;
+	struct list_head	node;
+};
+
 static void __iomem *mux_base;
 
 static inline u16 omap_mux_read(u16 reg)
@@ -57,6 +62,10 @@ static inline void omap_mux_write(u16 val, u16 reg)
 		__raw_writew(val, mux_base + reg);
 }
 
+#ifdef CONFIG_OMAP_MUX
+
+static struct omap_mux_cfg arch_mux_cfg;
+
 /* NOTE: See mux.h for the enumeration */
 
 #ifdef CONFIG_ARCH_OMAP24XX
@@ -667,8 +676,8 @@ int __init omap2_mux_init(void)
 		mux_pbase = OMAP2420_CTRL_BASE + OMAP_MUX_BASE_OFFSET;
 	else if (cpu_is_omap2430())
 		mux_pbase = OMAP243X_CTRL_BASE + OMAP_MUX_BASE_OFFSET;
-	else if (cpu_is_omap34xx())
-		mux_pbase = OMAP343X_CTRL_BASE + OMAP_MUX_BASE_OFFSET;
+	else
+		return -ENODEV;
 
 	mux_base = ioremap(mux_pbase, OMAP_MUX_BASE_SZ);
 	if (!mux_base) {
@@ -689,4 +698,431 @@ int __init omap2_mux_init(void)
 	return omap_mux_register(&arch_mux_cfg);
 }
 
+#endif	/* CONFIG_OMAP_MUX */
+
+/*----------------------------------------------------------------------------*/
+
+#ifdef CONFIG_ARCH_OMAP34XX
+
+static LIST_HEAD(muxmodes);
+static DEFINE_MUTEX(muxmode_mutex);
+
+#ifdef CONFIG_OMAP_MUX
+
+static char *omap_mux_options;
+
+int __init omap_mux_init_gpio(int gpio, int val)
+{
+	struct omap_mux_entry *e;
+	int found = 0;
+
+	if (!gpio)
+		return -EINVAL;
+
+	list_for_each_entry(e, &muxmodes, node) {
+		struct omap_mux *m = &e->mux;
+		if (gpio == m->gpio) {
+			u16 old_mode;
+			u16 mux_mode;
+
+			old_mode = omap_mux_read(m->reg_offset);
+			mux_mode = val & ~(OMAP_MUX_NR_MODES - 1);
+			mux_mode |= OMAP_MUX_MODE4;
+			printk(KERN_DEBUG "mux: Setting signal "
+				"%s.gpio%i 0x%04x -> 0x%04x\n",
+				m->muxnames[0], gpio, old_mode, mux_mode);
+			omap_mux_write(mux_mode, m->reg_offset);
+			found++;
+		}
+	}
+
+	if (found == 1)
+		return 0;
+
+	if (found > 1) {
+		printk(KERN_ERR "mux: Multiple gpio paths for gpio%i\n", gpio);
+		return -EINVAL;
+	}
+
+	printk(KERN_ERR "mux: Could not set gpio%i\n", gpio);
+
+	return -ENODEV;
+}
+
+int __init omap_mux_init_signal(char *muxname, int val)
+{
+	struct omap_mux_entry *e;
+	char *m0_name = NULL, *mode_name = NULL;
+	int found = 0;
+
+	mode_name = strchr(muxname, '.');
+	if (mode_name) {
+		*mode_name = '\0';
+		mode_name++;
+		m0_name = muxname;
+	} else {
+		mode_name = muxname;
+	}
+
+	list_for_each_entry(e, &muxmodes, node) {
+		struct omap_mux *m = &e->mux;
+		char *m0_entry = m->muxnames[0];
+		int i;
+
+		if (m0_name && strcmp(m0_name, m0_entry))
+			continue;
+
+		for (i = 0; i < OMAP_MUX_NR_MODES; i++) {
+			char *mode_cur = m->muxnames[i];
+
+			if (!mode_cur)
+				continue;
+
+			if (!strcmp(mode_name, mode_cur)) {
+				u16 old_mode;
+				u16 mux_mode;
+
+				old_mode = omap_mux_read(m->reg_offset);
+				mux_mode = val | i;
+				printk(KERN_DEBUG "mux: Setting signal "
+					"%s.%s 0x%04x -> 0x%04x\n",
+					m0_entry, muxname, old_mode, mux_mode);
+				omap_mux_write(mux_mode, m->reg_offset);
+				found++;
+			}
+		}
+	}
+
+	if (found == 1)
+		return 0;
+
+	if (found > 1) {
+		printk(KERN_ERR "mux: Multiple signal paths (%i) for %s\n",
+				found, muxname);
+		return -EINVAL;
+	}
+
+	printk(KERN_ERR "mux: Could not set signal %s\n", muxname);
+
+	return -ENODEV;
+}
+
+static void __init omap_mux_free_names(struct omap_mux *m)
+{
+	int i;
+
+	for (i = 0; i < OMAP_MUX_NR_MODES; i++)
+		kfree(m->muxnames[i]);
+
+#ifdef CONFIG_DEBUG_FS
+	for (i = 0; i < OMAP_MUX_NR_SIDES; i++)
+		kfree(m->balls[i]);
+#endif
+
+}
+
+/* Free all data except for GPIO pins unless CONFIG_DEBUG_FS is set */
+static int __init omap_mux_late_init(void)
+{
+	struct omap_mux_entry *e, *tmp;
+
+	list_for_each_entry_safe(e, tmp, &muxmodes, node) {
+		struct omap_mux *m = &e->mux;
+		u16 mode = omap_mux_read(m->reg_offset);
+
+		if (OMAP_MODE_GPIO(mode))
+			continue;
+
+#ifndef CONFIG_DEBUG_FS
+		mutex_lock(&muxmode_mutex);
+		list_del(&e->node);
+		mutex_unlock(&muxmode_mutex);
+		omap_mux_free_names(m);
+		kfree(m);
 #endif
+
+	}
+
+	return 0;
+}
+late_initcall(omap_mux_late_init);
+
+static void __init omap_mux_package_fixup(struct omap_mux *p,
+					struct omap_mux *superset)
+{
+	while (p->reg_offset !=  OMAP_MUX_TERMINATOR) {
+		struct omap_mux *s = superset;
+		int found = 0;
+
+		while (s->reg_offset != OMAP_MUX_TERMINATOR) {
+			if (s->reg_offset == p->reg_offset) {
+				*s = *p;
+				found++;
+				break;
+			}
+			s++;
+		}
+		if (!found)
+			printk(KERN_ERR "mux: Unknown entry offset 0x%x\n",
+					p->reg_offset);
+		p++;
+	}
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+static void __init omap_mux_package_init_balls(struct omap_ball *b,
+				struct omap_mux *superset)
+{
+	while (b->reg_offset != OMAP_MUX_TERMINATOR) {
+		struct omap_mux *s = superset;
+		int found = 0;
+
+		while (s->reg_offset != OMAP_MUX_TERMINATOR) {
+			if (s->reg_offset == b->reg_offset) {
+				s->balls[0] = b->balls[0];
+				s->balls[1] = b->balls[1];
+				found++;
+				break;
+			}
+			s++;
+		}
+		if (!found)
+			printk(KERN_ERR "mux: Unknown ball offset 0x%x\n",
+					b->reg_offset);
+		b++;
+	}
+}
+
+#else	/* CONFIG_DEBUG_FS */
+
+static inline void omap_mux_package_init_balls(struct omap_ball *b,
+					struct omap_mux *superset)
+{
+}
+
+#endif	/* CONFIG_DEBUG_FS */
+
+static int __init omap_mux_setup(char *options)
+{
+	if (!options)
+		return 0;
+
+	omap_mux_options = options;
+
+	return 1;
+}
+__setup("omap_mux=", omap_mux_setup);
+
+/*
+ * Note that the omap_mux=some.signal1=0x1234,some.signal2=0x1234
+ * cmdline options only override the bootloader values.
+ * During development, please enable CONFIG_DEBUG_FS, and use the
+ * signal specific entries under debugfs.
+ */
+static void __init omap_mux_set_cmdline_signals(void)
+{
+	char *options, *next_opt, *token;
+
+	if (!omap_mux_options)
+		return;
+
+	options = kmalloc(strlen(omap_mux_options) + 1, GFP_KERNEL);
+	if (!options)
+		return;
+
+	strcpy(options, omap_mux_options);
+	next_opt = options;
+
+	while ((token = strsep(&next_opt, ",")) != NULL) {
+		char *keyval, *name;
+		unsigned long val;
+
+		keyval = token;
+		name = strsep(&keyval, "=");
+		if (name) {
+			int res;
+
+			res = strict_strtoul(keyval, 0x10, &val);
+			if (res < 0)
+				continue;
+
+			omap_mux_init_signal(name, (u16)val);
+		}
+	}
+
+	kfree(options);
+}
+
+static void __init omap_mux_set_board_signals(struct omap_board_mux *board_mux)
+{
+	while (board_mux->reg_offset !=  OMAP_MUX_TERMINATOR) {
+		omap_mux_write(board_mux->value, board_mux->reg_offset);
+		board_mux++;
+	}
+}
+
+static int __init omap_mux_copy_names(struct omap_mux *src,
+					struct omap_mux *dst)
+{
+	int i;
+
+	for (i = 0; i < OMAP_MUX_NR_MODES; i++) {
+		if (src->muxnames[i]) {
+			dst->muxnames[i] =
+				kmalloc(strlen(src->muxnames[i]) + 1,
+					GFP_KERNEL);
+			if (!dst->muxnames[i])
+				goto free;
+			strcpy(dst->muxnames[i], src->muxnames[i]);
+		}
+	}
+
+#ifdef CONFIG_DEBUG_FS
+	for (i = 0; i < OMAP_MUX_NR_SIDES; i++) {
+		if (src->balls[i]) {
+			dst->balls[i] =
+				kmalloc(strlen(src->balls[i]) + 1,
+					GFP_KERNEL);
+			if (!dst->balls[i])
+				goto free;
+			strcpy(dst->balls[i], src->balls[i]);
+		}
+	}
+#endif
+
+	return 0;
+
+free:
+	omap_mux_free_names(dst);
+	return -ENOMEM;
+
+}
+
+#endif	/* CONFIG_OMAP_MUX */
+
+static u16 omap_mux_get_by_gpio(int gpio)
+{
+	struct omap_mux_entry *e;
+	u16 offset = OMAP_MUX_TERMINATOR;
+
+	list_for_each_entry(e, &muxmodes, node) {
+		struct omap_mux *m = &e->mux;
+		if (m->gpio == gpio) {
+			offset = m->reg_offset;
+			break;
+		}
+	}
+
+	return offset;
+}
+
+/* Needed for dynamic muxing of GPIO pins for off-idle */
+u16 omap_mux_get_gpio(int gpio)
+{
+	u16 offset;
+
+	offset = omap_mux_get_by_gpio(gpio);
+	if (offset == OMAP_MUX_TERMINATOR) {
+		printk(KERN_ERR "mux: Could not get gpio%i\n", gpio);
+		return offset;
+	}
+
+	return omap_mux_read(offset);
+}
+
+/* Needed for dynamic muxing of GPIO pins for off-idle */
+void omap_mux_set_gpio(u16 val, int gpio)
+{
+	u16 offset;
+
+	offset = omap_mux_get_by_gpio(gpio);
+	if (offset == OMAP_MUX_TERMINATOR) {
+		printk(KERN_ERR "mux: Could not set gpio%i\n", gpio);
+		return;
+	}
+
+	omap_mux_write(val, offset);
+}
+
+static struct omap_mux * __init omap_mux_list_add(struct omap_mux *src)
+{
+	struct omap_mux_entry *entry;
+	struct omap_mux *m;
+
+	entry = kzalloc(sizeof(struct omap_mux_entry), GFP_KERNEL);
+	if (!entry)
+		return NULL;
+
+	m = &entry->mux;
+	memcpy(m, src, sizeof(struct omap_mux_entry));
+
+#ifdef CONFIG_OMAP_MUX
+	if (omap_mux_copy_names(src, m)) {
+		kfree(entry);
+		return NULL;
+	}
+#endif
+
+	mutex_lock(&muxmode_mutex);
+	list_add_tail(&entry->node, &muxmodes);
+	mutex_unlock(&muxmode_mutex);
+
+	return m;
+}
+
+/*
+ * Note if CONFIG_OMAP_MUX is not selected, we will only initialize
+ * the GPIO to mux offset mapping that is needed for dynamic muxing
+ * of GPIO pins for off-idle.
+ */
+static void __init omap_mux_init_list(struct omap_mux *superset)
+{
+	while (superset->reg_offset !=  OMAP_MUX_TERMINATOR) {
+		struct omap_mux *entry;
+
+#ifndef CONFIG_OMAP_MUX
+		/* Skip pins that are not muxed as GPIO by bootloader */
+		if (!OMAP_MODE_GPIO(omap_mux_read(superset->reg_offset))) {
+			superset++;
+			continue;
+		}
+#endif
+
+		entry = omap_mux_list_add(superset);
+		if (!entry) {
+			printk(KERN_ERR "mux: Could not add entry\n");
+			return;
+		}
+		superset++;
+	}
+}
+
+int __init omap_mux_init(u32 mux_pbase, u32 mux_size,
+				struct omap_mux *superset,
+				struct omap_mux *package_subset,
+				struct omap_board_mux *board_mux,
+				struct omap_ball *package_balls)
+{
+	if (mux_base)
+		return -EBUSY;
+
+	mux_base = ioremap(mux_pbase, mux_size);
+	if (!mux_base) {
+		printk(KERN_ERR "mux: Could not ioremap\n");
+		return -ENODEV;
+	}
+
+#ifdef CONFIG_OMAP_MUX
+	omap_mux_package_fixup(package_subset, superset);
+	omap_mux_package_init_balls(package_balls, superset);
+	omap_mux_set_cmdline_signals();
+	omap_mux_set_board_signals(board_mux);
+#endif
+
+	omap_mux_init_list(superset);
+
+	return 0;
+}
+
+#endif	/* CONFIG_ARCH_OMAP34XX */
diff --git a/arch/arm/mach-omap2/mux.h b/arch/arm/mach-omap2/mux.h
new file mode 100644
index 0000000..bebe9cc
--- /dev/null
+++ b/arch/arm/mach-omap2/mux.h
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2009 Nokia
+ * Copyright (C) 2009 Texas Instruments
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define OMAP_MUX_TERMINATOR	0xffff
+
+/* 34xx mux mode options for each pin. See TRM for options */
+#define OMAP_MUX_MODE0      0
+#define OMAP_MUX_MODE1      1
+#define OMAP_MUX_MODE2      2
+#define OMAP_MUX_MODE3      3
+#define OMAP_MUX_MODE4      4
+#define OMAP_MUX_MODE5      5
+#define OMAP_MUX_MODE6      6
+#define OMAP_MUX_MODE7      7
+
+/* 24xx/34xx mux bit defines */
+#define OMAP_PULL_ENA			(1 << 3)
+#define OMAP_PULL_UP			(1 << 4)
+#define OMAP_ALTELECTRICALSEL		(1 << 5)
+
+/* 34xx specific mux bit defines */
+#define OMAP_INPUT_EN			(1 << 8)
+#define OMAP_OFF_EN			(1 << 9)
+#define OMAP_OFFOUT_EN			(1 << 10)
+#define OMAP_OFFOUT_VAL			(1 << 11)
+#define OMAP_OFF_PULL_EN		(1 << 12)
+#define OMAP_OFF_PULL_UP		(1 << 13)
+#define OMAP_WAKEUP_EN			(1 << 14)
+
+/* Active pin states */
+#define OMAP_PIN_OUTPUT			0
+#define OMAP_PIN_INPUT			OMAP_INPUT_EN
+#define OMAP_PIN_INPUT_PULLUP		(OMAP_PULL_ENA | OMAP_INPUT_EN \
+						| OMAP_PULL_UP)
+#define OMAP_PIN_INPUT_PULLDOWN		(OMAP_PULL_ENA | OMAP_INPUT_EN)
+
+/* Off mode states */
+#define OMAP_PIN_OFF_NONE		0
+#define OMAP_PIN_OFF_OUTPUT_HIGH	(OMAP_OFF_EN | OMAP_OFFOUT_EN \
+						| OMAP_OFFOUT_VAL)
+#define OMAP_PIN_OFF_OUTPUT_LOW		(OMAP_OFF_EN | OMAP_OFFOUT_EN)
+#define OMAP_PIN_OFF_INPUT_PULLUP	(OMAP_OFF_EN | OMAP_OFF_PULL_EN \
+						| OMAP_OFF_PULL_UP)
+#define OMAP_PIN_OFF_INPUT_PULLDOWN	(OMAP_OFF_EN | OMAP_OFF_PULL_EN)
+#define OMAP_PIN_OFF_WAKEUPENABLE	OMAP_WAKEUP_EN
+
+#define OMAP_MODE_GPIO(x)	(((x) & OMAP_MUX_MODE7) == OMAP_MUX_MODE4)
+
+/* Flags for omap_mux_init */
+#define OMAP_PACKAGE_MASK		0xffff
+#define OMAP_PACKAGE_CUS		3		/* 423-pin 0.65 */
+#define OMAP_PACKAGE_CBB		2		/* 515-pin 0.40 0.50 */
+#define OMAP_PACKAGE_CBC		1		/* 515-pin 0.50 0.65 */
+
+
+#define OMAP_MUX_NR_MODES	8			/* Available modes */
+#define OMAP_MUX_NR_SIDES	2			/* Bottom & top */
+
+/**
+ * struct omap_mux - data for omap mux register offset and it's value
+ * @reg_offset:	mux register offset from the mux base
+ * @gpio:	GPIO number
+ * @muxnames:	available signal modes for a ball
+ */
+struct omap_mux {
+	u16	reg_offset;
+	u16	gpio;
+#ifdef CONFIG_OMAP_MUX
+	char	*muxnames[OMAP_MUX_NR_MODES];
+#ifdef CONFIG_DEBUG_FS
+	char	*balls[OMAP_MUX_NR_SIDES];
+#endif
+#endif
+};
+
+/**
+ * struct omap_ball - data for balls on omap package
+ * @reg_offset:	mux register offset from the mux base
+ * @balls:	available balls on the package
+ */
+struct omap_ball {
+	u16	reg_offset;
+	char	*balls[OMAP_MUX_NR_SIDES];
+};
+
+/**
+ * struct omap_board_mux - data for initializing mux registers
+ * @reg_offset:	mux register offset from the mux base
+ * @mux_value:	desired mux value to set
+ */
+struct omap_board_mux {
+	u16	reg_offset;
+	u16	value;
+};
+
+#if defined(CONFIG_OMAP_MUX) && defined(CONFIG_ARCH_OMAP34XX)
+
+/**
+ * omap_mux_init_gpio - initialize a signal based on the GPIO number
+ * @gpio:		GPIO number
+ * @val:		Options for the mux register value
+ */
+int omap_mux_init_gpio(int gpio, int val);
+
+/**
+ * omap_mux_init_signal - initialize a signal based on the signal name
+ * @muxname:		Mux name in mode0_name.signal_name format
+ * @val:		Options for the mux register value
+ */
+int omap_mux_init_signal(char *muxname, int val);
+
+#else
+
+static inline int omap_mux_init_gpio(int gpio, int val)
+{
+	return 0;
+}
+static inline int omap_mux_init_signal(char *muxname, int val)
+{
+	return 0;
+}
+
+#endif
+
+/**
+ * omap_mux_get_gpio() - get mux register value based on GPIO number
+ * @gpio:		GPIO number
+ *
+ */
+u16 omap_mux_get_gpio(int gpio);
+
+/**
+ * omap_mux_set_gpio() - set mux register value based on GPIO number
+ * @val:		New mux register value
+ * @gpio:		GPIO number
+ *
+ */
+void omap_mux_set_gpio(u16 val, int gpio);
+
+/**
+ * omap3_mux_init() - initialize mux system with board specific set
+ * @board_mux:		Board specific mux table
+ * @flags:		OMAP package type used for the board
+ */
+int omap3_mux_init(struct omap_board_mux *board_mux, int flags);
+
+/**
+ * omap_mux_init - private mux init function, do not call
+ */
+int omap_mux_init(u32 mux_pbase, u32 mux_size,
+				struct omap_mux *superset,
+				struct omap_mux *package_subset,
+				struct omap_board_mux *board_mux,
+				struct omap_ball *package_balls);
diff --git a/arch/arm/plat-omap/mux.c b/arch/arm/plat-omap/mux.c
index 05aebca..0670363 100644
--- a/arch/arm/plat-omap/mux.c
+++ b/arch/arm/plat-omap/mux.c
@@ -54,8 +54,12 @@ int __init_or_module omap_cfg_reg(const unsigned long index)
 {
 	struct pin_config *reg;
 
-	if (cpu_is_omap44xx())
-		return 0;
+	if (cpu_is_omap34xx() || cpu_is_omap44xx()) {
+		printk(KERN_ERR "mux: Broken omap_cfg_reg(%lu) entry\n",
+				index);
+		WARN_ON(1);
+		return -EINVAL;
+	}
 
 	if (mux_cfg == NULL) {
 		printk(KERN_ERR "Pin mux table not initialized\n");

RE:[PATCH 2/9] omap: mux: Add new style pin multiplexing code for omap3

[rockefeller]

Hi Tony,
   In the implementation of omap_mux_init_signal(char *muxname, int val)
in arch/arm/mach-omap2/mux.c, it will modify the muxname of
caller that passed in and not recover it, did you mean to implement 
to do so?(I try to explain my point of view as 2 examples below).

[Example 1]
For a XIP device(NOR type), a caller function might be codeed like
below:

omap_mux_init_signal("muxname.mode7", 0xFFFF);

and in this case, the string "muxname.mode7" might be a const string
and not be modified.

[Example 2]
For a NAND device, a caller might be coded like below:

static char *pin_mux_name = "muxname.mode7";

function1()
{
omap_mux_init_signal(pin_mux_name, 0xFFFF);
}

function2()
{
omap_mux_init_signal(pin_mux_name, 0x0000);
}

void main()
{
function1();
function2();
}

Because "muxname.mode7" in in RAM is modifiable, after function call
to function1(), the *pine_mux_name will be "muxname" and therefore when
calls to function2() to try to set this pin in mode7 with value 0x0000
might be un-expected result.

Re: [PATCH 2/9] omap: mux: Add new style pin multiplexing code for omap3

[Cousson, Benoit]

On 8/27/2010 4:29 AM, rockefeller wrote:
> Hi Tony,
>     In the implementation of omap_mux_init_signal(char *muxname, int val)
> in arch/arm/mach-omap2/mux.c, it will modify the muxname of
> caller that passed in and not recover it, did you mean to implement
> to do so?(I try to explain my point of view as 2 examples below).

I'm not sure it was really done on purpose. It works today because none 
of the following cases are really happening.

>
> [Example 1]
> For a XIP device(NOR type), a caller function might be codeed like
> below:
>
> omap_mux_init_signal("muxname.mode7", 0xFFFF);
>
> and in this case, the string "muxname.mode7" might be a const string
> and not be modified.

That case seems to be a valid one.

>
> [Example 2]
> For a NAND device, a caller might be coded like below:
>
> static char *pin_mux_name = "muxname.mode7";
>
> function1()
> {
> omap_mux_init_signal(pin_mux_name, 0xFFFF);
> }
>
> function2()
> {
> omap_mux_init_signal(pin_mux_name, 0x0000);
> }
>
> void main()
> {
> function1();
> function2();
> }
>
> Because "muxname.mode7" in in RAM is modifiable, after function call
> to function1(), the *pine_mux_name will be "muxname" and therefore when
> calls to function2() to try to set this pin in mode7 with value 0x0000
> might be un-expected result.

In theory the pin mux is done once at init time, so I'm not sure this 
case is supposed to happen. Is it a real case?

Anyway, I think that a simple strlcpy(tmp, muxname, 32) in 
omap_mux_init_signal can fix it.

Do you mind submitting a patch to fix that?

Thanks,
Benoit

Re: [PATCH 2/9] omap: mux: Add new style pin multiplexing code for omap3

[Tony Lindgren]

* Cousson, Benoit <b-cousson@ti.com> [100827 02:17]:
> On 8/27/2010 4:29 AM, rockefeller wrote:
> >
> >Because "muxname.mode7" in in RAM is modifiable, after function call
> >to function1(), the *pine_mux_name will be "muxname" and therefore when
> >calls to function2() to try to set this pin in mode7 with value 0x0000
> >might be un-expected result.
> 
> In theory the pin mux is done once at init time, so I'm not sure
> this case is supposed to happen. Is it a real case?
> 
> Anyway, I think that a simple strlcpy(tmp, muxname, 32) in
> omap_mux_init_signal can fix it.
> 
> Do you mind submitting a patch to fix that?

Yeah that's a bug, we should not trash the muxname.

Regards,

Tony

Re: [PATCH 2/9] omap: mux: Add new style pin multiplexing code for omap3

[rockefeller]

On Fri, 2010-08-27 at 11:24 +0200, Cousson, Benoit wrote:
> On 8/27/2010 4:29 AM, rockefeller wrote:
> > Hi Tony,
> >     In the implementation of omap_mux_init_signal(char *muxname, int val)
> > in arch/arm/mach-omap2/mux.c, it will modify the muxname of
> > caller that passed in and not recover it, did you mean to implement
> > to do so?(I try to explain my point of view as 2 examples below).
> 
> I'm not sure it was really done on purpose. It works today because none 
> of the following cases are really happening.
> 
> >
> > [Example 1]
> > For a XIP device(NOR type), a caller function might be codeed like
> > below:
> >
> > omap_mux_init_signal("muxname.mode7", 0xFFFF);
> >
> > and in this case, the string "muxname.mode7" might be a const string
> > and not be modified.
> 
> That case seems to be a valid one.
> 
> >
> > [Example 2]
> > For a NAND device, a caller might be coded like below:
> >
> > static char *pin_mux_name = "muxname.mode7";
> >
> > function1()
> > {
> > omap_mux_init_signal(pin_mux_name, 0xFFFF);
> > }
> >
> > function2()
> > {
> > omap_mux_init_signal(pin_mux_name, 0x0000);
> > }
> >
> > void main()
> > {
> > function1();
> > function2();
> > }
> >
> > Because "muxname.mode7" in in RAM is modifiable, after function call
> > to function1(), the *pine_mux_name will be "muxname" and therefore when
> > calls to function2() to try to set this pin in mode7 with value 0x0000
> > might be un-expected result.
> 
> In theory the pin mux is done once at init time, so I'm not sure this 
> case is supposed to happen. Is it a real case?
I just encountered the issue when I ported 
http://dev.omapzoom.org/?p=modem-int/kernel.git;a=shortlog;h=refs/heads/xmm-3630
to Froyo(Android-2.6.32)
> 
> Anyway, I think that a simple strlcpy(tmp, muxname, 32) in 
> omap_mux_init_signal can fix it.
> 
> Do you mind submitting a patch to fix that?
> 
> Thanks,
> Benoit
I would like to introduce a new function omap_mux_name_strcmp() that
adapted from strcmp() as below and verified with android-2.6.32 and
it works fine.

diff --git a/arch/arm/mach-omap2/mux.c b/arch/arm/mach-omap2/mux.c
index 6c2f8f0..b61c24a 100644
--- a/arch/arm/mach-omap2/mux.c
+++ b/arch/arm/mach-omap2/mux.c
@@ -127,17 +127,34 @@ int __init omap_mux_init_gpio(int gpio, int val)
        return 0;
 }
 
+static int omap_mux_name_strcmp(const char * mux_name, const char
*mode_name)
+{
+       unsigned char c1, c2;
+
+       while (1) {
+               c1 = *mux_name++;
+               c2 = *mode_name++;
+               if (c1 != c2) {
+                       if ((c1 == 0 && c2 == '.') || (c1 == '.' && c2
== 0))
+                               break;
+                       else
+                               return c1 < c2 ? -1 : 1;
+               }
+               if (!c1)
+                       break;
+       }
+       return 0;
+}
+
 int __init omap_mux_init_signal(char *muxname, int val)
 {
        struct omap_mux_entry *e;
-       char *m0_name = NULL, *mode_name = NULL;
+       char *mode_name = NULL;
        int found = 0;
 
        mode_name = strchr(muxname, '.');
        if (mode_name) {
-               *mode_name = '\0';
                mode_name++;
-               m0_name = muxname;
        } else {
                mode_name = muxname;
        }
@@ -147,7 +164,7 @@ int __init omap_mux_init_signal(char *muxname, int
val)
                char *m0_entry = m->muxnames[0];
                int i;
 
-               if (m0_name && strcmp(m0_name, m0_entry))
+               if (m0_entry && omap_mux_name_strcmp(muxname, m0_entry))
                        continue;
 
                for (i = 0; i < OMAP_MUX_NR_MODES; i++) {
@@ -156,7 +173,7 @@ int __init omap_mux_init_signal(char *muxname, int
val)
                        if (!mode_cur)
                                continue;
 
-                       if (!strcmp(mode_name, mode_cur)) {
+                       if (!omap_mux_name_strcmp(mode_name, mode_cur))
{
                                u16 old_mode;
                                u16 mux_mode;

> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 2/9] omap: mux: Add new style pin multiplexing code for omap3

[Tony Lindgren]

Hi,

Sorry for the delay on responding to this..

* rockefeller <rockefeller.lin@innocomm.com> [100829 18:23]:
> On Fri, 2010-08-27 at 11:24 +0200, Cousson, Benoit wrote:
>
> I would like to introduce a new function omap_mux_name_strcmp() that
> adapted from strcmp() as below and verified with android-2.6.32 and
> it works fine.

Looks like we can also do it with strncmp and keep it const, then
we don't have to ad a custom strcmp function.

Care to test the following patch and see if it solves your problem?

Regards,

Tony


From: Tony Lindgren <tony@atomide.com>
Date: Tue, 28 Sep 2010 16:58:04 -0700
Subject: [PATCH] omap: Fix omap_mux_init_signal not to trash muxname

Otherwise the muxname passed to the function will get truncated.

Based on an earlier patch by rockefeller.lin@innocomm.com.

Reported-by: rockefeller.lin@innocomm.com
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/mach-omap2/mux.c b/arch/arm/mach-omap2/mux.c
index 6c2f8f0..e33740c 100644
--- a/arch/arm/mach-omap2/mux.c
+++ b/arch/arm/mach-omap2/mux.c
@@ -127,17 +127,16 @@ int __init omap_mux_init_gpio(int gpio, int val)
 	return 0;
 }
 
-int __init omap_mux_init_signal(char *muxname, int val)
+int __init omap_mux_init_signal(const char *muxname, int val)
 {
 	struct omap_mux_entry *e;
-	char *m0_name = NULL, *mode_name = NULL;
-	int found = 0;
+	const char *mode_name;
+	int found = 0, mode0_len = 0;
 
 	mode_name = strchr(muxname, '.');
 	if (mode_name) {
-		*mode_name = '\0';
+		mode0_len = strlen(muxname) - strlen(mode_name);
 		mode_name++;
-		m0_name = muxname;
 	} else {
 		mode_name = muxname;
 	}
@@ -147,9 +146,11 @@ int __init omap_mux_init_signal(char *muxname, int val)
 		char *m0_entry = m->muxnames[0];
 		int i;
 
-		if (m0_name && strcmp(m0_name, m0_entry))
+		/* First check for full name in mode0.muxmode format */
+		if (mode0_len && strncmp(muxname, m0_entry, mode0_len))
 			continue;
 
+		/* Then check for muxmode only */
 		for (i = 0; i < OMAP_MUX_NR_MODES; i++) {
 			char *mode_cur = m->muxnames[i];
 
diff --git a/arch/arm/mach-omap2/mux.h b/arch/arm/mach-omap2/mux.h
index a8e040c..350c04f 100644
--- a/arch/arm/mach-omap2/mux.h
+++ b/arch/arm/mach-omap2/mux.h
@@ -120,7 +120,7 @@ int omap_mux_init_gpio(int gpio, int val);
  * @muxname:		Mux name in mode0_name.signal_name format
  * @val:		Options for the mux register value
  */
-int omap_mux_init_signal(char *muxname, int val);
+int omap_mux_init_signal(const char *muxname, int val);
 
 #else