twl4030: new-style driver conversion

More updates preparing for upstream merge of twl4030 driver:

 Basic fixes
   -	twl4030-core becomes a new-style I2C driver
   -	declare and use platform_data structure for that core
   -	stop hard-wiring the irq numbers
   -	check functionality that's really used:  I2C, not SMBus
 Cleanup:
   -	remove needless "client string"
   -	remove some fake "bool" types
   -	include catalog part numbers (TPS659{5,3,2}0)
   -	diagnostics should identify the driver!

To use this, all boards with these chips will need to declare this chip
when they declare their active I2C busses (done in a separate patch).

NOTE:  the TWL4030_IRQ_* symbols still need to vanish, along with other
global resource assignments associated with these chips.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>

drivers/i2c/chips/twl4030-core.c

 /*
- * twl4030_core.c - driver for TWL4030 PM and audio CODEC device
+ * twl4030_core.c - driver for TWL4030/TPS659x0 PM and audio CODEC devices
  *
  * Copyright (C) 2005-2006 Texas Instruments, Inc.
  *
@@ -56,14 +56,6 @@
 
 #define DRIVER_NAME			"twl4030"
 
-/* Macro Definitions */
-#define TWL_CLIENT_STRING		"TWL4030-ID"
-#define TWL_CLIENT_USED			1
-#define TWL_CLIENT_FREE			0
-
-/* IRQ Flags */
-#define FREE				0
-#define USED				1
 
 /* Primary Interrupt Handler on TWL4030 Registers */
 
@@ -293,26 +285,18 @@ static const struct twl4030_mod_iregs __initconst twl4030_mod_regs[] = {
 
 
 /* Helper functions */
-static int
-twl4030_detect_client(struct i2c_adapter *adapter, unsigned char sid);
-static int twl4030_attach_adapter(struct i2c_adapter *adapter);
-static int twl4030_detach_client(struct i2c_client *client);
 static void do_twl4030_irq(unsigned int irq, irq_desc_t *desc);
 
-static void twl_init_irq(void);
-
 /* Data Structures */
 /* To have info on T2 IRQ substem activated or not */
-static unsigned char twl_irq_used = FREE;
 static struct completion irq_event;
 
 /* Structure to define on TWL4030 Slave ID */
 struct twl4030_client {
-	struct i2c_client client;
-	const char client_name[sizeof(TWL_CLIENT_STRING) + 1];
+	struct i2c_client *client;
 	const unsigned char address;
 	const char adapter_index;
-	unsigned char inuse;
+	bool inuse;
 
 	/* max numb of i2c_msg required is for read =2 */
 	struct i2c_msg xfer_msg[2];
@@ -356,36 +340,22 @@ static struct twl4030mapping twl4030_map[TWL4030_MODULE_LAST + 1] = {
 static struct twl4030_client twl4030_modules[TWL4030_NUM_SLAVES] = {
 	{
 		.address	= TWL4030_SLAVEID_ID0,
-		.client_name	= TWL_CLIENT_STRING "0",
 		.adapter_index	= CONFIG_I2C_TWL4030_ID,
 	},
 	{
 		.address	= TWL4030_SLAVEID_ID1,
-		.client_name	= TWL_CLIENT_STRING "1",
 		.adapter_index	= CONFIG_I2C_TWL4030_ID,
 	},
 	{
 		.address	= TWL4030_SLAVEID_ID2,
-		.client_name	= TWL_CLIENT_STRING "2",
 		.adapter_index	= CONFIG_I2C_TWL4030_ID,
 	},
 	{
 		.address	= TWL4030_SLAVEID_ID3,
-		.client_name	= TWL_CLIENT_STRING "3",
 		.adapter_index	= CONFIG_I2C_TWL4030_ID,
 	},
 };
 
-/* One Client Driver , 4 Clients */
-static struct i2c_driver twl4030_driver = {
-	.driver	= {
-		.name	= DRIVER_NAME,
-		.owner	= THIS_MODULE,
-	},
-	.attach_adapter	= twl4030_attach_adapter,
-	.detach_client	= twl4030_detach_client,
-};
-
 /*
  * TWL4030 doesn't have PIH mask, hence dummy function for mask
  * and unmask.
@@ -425,15 +395,14 @@ int twl4030_i2c_write(u8 mod_no, u8 *value, u8 reg, u8 num_bytes)
 	struct i2c_msg *msg;
 
 	if (unlikely(mod_no > TWL4030_MODULE_LAST)) {
-		pr_err("Invalid module Number\n");
+		pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
 		return -EPERM;
 	}
 	sid = twl4030_map[mod_no].sid;
 	twl = &twl4030_modules[sid];
 
-	if (unlikely(twl->inuse != TWL_CLIENT_USED)) {
-		pr_err("I2C Client[%d] is not initialized[%d]\n",
-		       sid, __LINE__);
+	if (unlikely(!twl->inuse)) {
+		pr_err("%s: client %d is not initialized\n", DRIVER_NAME, sid);
 		return -EPERM;
 	}
 	mutex_lock(&twl->xfer_lock);
@@ -448,7 +417,7 @@ int twl4030_i2c_write(u8 mod_no, u8 *value, u8 reg, u8 num_bytes)
 	msg->buf = value;
 	/* over write the first byte of buffer with the register address */
 	*value = twl4030_map[mod_no].base + reg;
-	ret = i2c_transfer(twl->client.adapter, twl->xfer_msg, 1);
+	ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 1);
 	mutex_unlock(&twl->xfer_lock);
 
 	/* i2cTransfer returns num messages.translate it pls.. */
@@ -476,15 +445,14 @@ int twl4030_i2c_read(u8 mod_no, u8 *value, u8 reg, u8 num_bytes)
 	struct i2c_msg *msg;
 
 	if (unlikely(mod_no > TWL4030_MODULE_LAST)) {
-		pr_err("Invalid module Number\n");
+		pr_err("%s: invalid module number %d\n", DRIVER_NAME, mod_no);
 		return -EPERM;
 	}
 	sid = twl4030_map[mod_no].sid;
 	twl = &twl4030_modules[sid];
 
-	if (unlikely(twl->inuse != TWL_CLIENT_USED)) {
-		pr_err("I2C Client[%d] is not initialized[%d]\n", sid,
-		       __LINE__);
+	if (unlikely(!twl->inuse)) {
+		pr_err("%s: client %d is not initialized\n", DRIVER_NAME, sid);
 		return -EPERM;
 	}
 	mutex_lock(&twl->xfer_lock);
@@ -501,7 +469,7 @@ int twl4030_i2c_read(u8 mod_no, u8 *value, u8 reg, u8 num_bytes)
 	msg->flags = I2C_M_RD;	/* Read the register value */
 	msg->len = num_bytes;	/* only n bytes */
 	msg->buf = value;
-	ret = i2c_transfer(twl->client.adapter, twl->xfer_msg, 2);
+	ret = i2c_transfer(twl->client->adapter, twl->xfer_msg, 2);
 	mutex_unlock(&twl->xfer_lock);
 
 	/* i2cTransfer returns num messages.translate it pls.. */
@@ -608,6 +576,8 @@ static void do_twl4030_module_irq(unsigned int irq, irq_desc_t *desc)
 				" be masked!\n", irq);
 }
 
+static unsigned twl4030_irq_base;
+
 /*
  * twl4030_irq_thread() runs as a kernel thread.  It queries the twl4030
  * interrupt controller to see which modules are generating interrupt requests
@@ -644,7 +614,7 @@ static int twl4030_irq_thread(void *data)
 			continue;
 		}
 
-		for (module_irq = TWL4030_IRQ_BASE; 0 != pih_isr;
+		for (module_irq = twl4030_irq_base; 0 != pih_isr;
 			 pih_isr >>= 1, module_irq++) {
 			if (pih_isr & 0x1) {
 				irq_desc_t *d = irq_desc + module_irq;
@@ -693,78 +663,17 @@ static void do_twl4030_irq(unsigned int irq, irq_desc_t *desc)
 	}
 }
 
-/* attach a client to the adapter */
-static int __init twl4030_detect_client(struct i2c_adapter *adapter,
-					unsigned char sid)
-{
-	int err = 0;
-	struct twl4030_client *twl;
-
-	if (unlikely(sid >= TWL4030_NUM_SLAVES)) {
-		pr_err("sid[%d] > MOD_LAST[%d]\n", sid, TWL4030_NUM_SLAVES);
-		return -EPERM;
-	}
-
-	/* Check basic functionality */
-	err = i2c_check_functionality(adapter,
-			I2C_FUNC_SMBUS_WORD_DATA
-			| I2C_FUNC_SMBUS_WRITE_BYTE);
-	if (!err) {
-		pr_err("SlaveID=%d functionality check failed\n", sid);
-		return err;
-	}
-	twl = &twl4030_modules[sid];
-	if (unlikely(twl->inuse)) {
-		pr_err("Client %s is already in use\n", twl->client_name);
-		return -EPERM;
-	}
-
-	memset(&twl->client, 0, sizeof(struct i2c_client));
-
-	twl->client.addr	= twl->address;
-	twl->client.adapter	= adapter;
-	twl->client.driver	= &twl4030_driver;
-
-	memcpy(&twl->client.name, twl->client_name,
-			sizeof(TWL_CLIENT_STRING) + 1);
-
-	pr_info("TWL4030: TRY attach Slave %s on Adapter %s [%x]\n",
-				twl->client_name, adapter->name, err);
-
-	err = i2c_attach_client(&twl->client);
-	if (err) {
-		pr_err("Couldn't attach Slave %s on Adapter"
-		       "%s [%x]\n", twl->client_name, adapter->name, err);
-	} else {
-		twl->inuse = TWL_CLIENT_USED;
-		mutex_init(&twl->xfer_lock);
-	}
-
-	return err;
-}
-
-static int add_children(void)
+static int add_children(struct twl4030_platform_data *pdata)
 {
-	static bool		children;
-
 	struct platform_device	*pdev = NULL;
 	struct twl4030_client	*twl = NULL;
 	int			status = 0;
 
-	/* FIXME this doesn't yet set up platform_data for anything;
-	 * it can't be available until this becomes a "new style"
-	 * I2C driver.  Similarly, a new style driver will know it
-	 * didn't already initialize its children.
-	 */
-
-	if (children)
-		return 0;
-
 #ifdef CONFIG_RTC_DRV_TWL4030
 	pdev = platform_device_alloc("twl4030_rtc", -1);
 	if (pdev) {
 		twl = &twl4030_modules[TWL4030_SLAVENUM_NUM3];
-		pdev->dev.parent = &twl->client.dev;
+		pdev->dev.parent = &twl->client->dev;
 		device_init_wakeup(&pdev->dev, 1);
 
 		/*
@@ -788,66 +697,9 @@ static int add_children(void)
 		status = -ENOMEM;
 #endif
 
-	children = true;
 	return status;
 }
 
-/* adapter callback */
-static int __init twl4030_attach_adapter(struct i2c_adapter *adapter)
-{
-	int i;
-	int ret = 0;
-	static int twl_i2c_adapter = 1;
-
-	for (i = 0; i < TWL4030_NUM_SLAVES; i++) {
-		/* Check if I need to hook on to this adapter or not */
-		if (twl4030_modules[i].adapter_index == twl_i2c_adapter) {
-			ret = twl4030_detect_client(adapter, i);
-			if (ret)
-				goto free_client;
-		}
-	}
-	twl_i2c_adapter++;
-
-	add_children();
-
-	/*
-	 * Check if the PIH module is initialized, if yes, then init
-	 * the T2 Interrupt subsystem
-	 */
-	if ((twl4030_modules[twl4030_map[TWL4030_MODULE_PIH].sid].inuse ==
-		TWL_CLIENT_USED) && (twl_irq_used != USED)) {
-		twl_init_irq();
-		twl_irq_used = USED;
-	}
-	return 0;
-
-free_client:
-	pr_err("TWL_CLIENT(Idx=%d] registration failed[0x%x]\n", i, ret);
-
-	/* ignore current slave..it never got registered */
-	i--;
-	while (i >= 0) {
-		/* now remove all those from the current adapter... */
-		if (twl4030_modules[i].adapter_index == twl_i2c_adapter)
-			(void)twl4030_detach_client(&twl4030_modules[i].client);
-		i--;
-	}
-	return ret;
-}
-
-/* adapter's callback */
-static int twl4030_detach_client(struct i2c_client *client)
-{
-	int err;
-	err = i2c_detach_client(client);
-	if (err) {
-		pr_err("Client detach failed\n");
-		return err;
-	}
-	return 0;
-}
-
 static struct task_struct * __init start_twl4030_irq_thread(int irq)
 {
 	struct task_struct *thread;
@@ -1005,12 +857,11 @@ static void __init twl4030_mask_clear_intrs(const struct twl4030_mod_iregs *t,
 }
 
 
-static void twl_init_irq(void)
+static void twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end)
 {
 	int	i;
 	int	res = 0;
 	char	*msg = "Unable to register interrupt subsystem";
-	unsigned int irq_num;
 
 	/*
 	 * Mask and clear all TWL4030 interrupts since initially we do
@@ -1019,15 +870,15 @@ static void twl_init_irq(void)
 	twl4030_mask_clear_intrs(twl4030_mod_regs,
 				 ARRAY_SIZE(twl4030_mod_regs));
 
+	twl4030_irq_base = irq_base;
+
 	/* install an irq handler for each of the PIH modules */
-	for (i = TWL4030_IRQ_BASE; i < TWL4030_IRQ_END; i++) {
+	for (i = irq_base; i < irq_end; i++) {
 		set_irq_chip(i, &twl4030_irq_chip);
 		set_irq_handler(i, do_twl4030_module_irq);
 		set_irq_flags(i, IRQF_VALID);
 	}
 
-	irq_num = (cpu_is_omap2430()) ? INT_24XX_SYS_NIRQ : INT_34XX_SYS_NIRQ;
-
 	/* install an irq handler to demultiplex the TWL4030 interrupt */
 	set_irq_data(irq_num, start_twl4030_irq_thread(irq_num));
 	set_irq_type(irq_num, IRQ_TYPE_EDGE_FALLING);
@@ -1035,24 +886,133 @@ static void twl_init_irq(void)
 
 	res = power_companion_init();
 	if (res < 0)
-		pr_err("%s[%d][%d]\n", msg, res, __LINE__);
+		pr_err("%s: %s[%d]\n", DRIVER_NAME, msg, res);
 }
 
+/*----------------------------------------------------------------------*/
+
+static int twl4030_remove(struct i2c_client *client)
+{
+	unsigned i;
+
+	/* FIXME undo twl_init_irq() */
+	if (twl4030_irq_base) {
+		dev_err(&client->dev, "can't yet clean up IRQs?\n");
+		return -ENOSYS;
+	}
+
+	for (i = 0; i < TWL4030_NUM_SLAVES; i++) {
+		struct twl4030_client	*twl = &twl4030_modules[i];
+
+		if (twl->client && twl->client != client)
+			i2c_unregister_device(twl->client);
+		twl4030_modules[i].client = NULL;
+		twl4030_modules[i].inuse = false;
+	}
+	return 0;
+}
+
+/* NOTE:  this driver only handles a single twl4030/tps659x0 chip */
+static int
+twl4030_probe(struct i2c_client *client, const struct i2c_device_id *id)
+{
+	int				status;
+	unsigned			i;
+	struct twl4030_platform_data	*pdata = client->dev.platform_data;
+
+	if (!pdata) {
+		dev_dbg(&client->dev, "no platform data?\n");
+		return -EINVAL;
+	}
+
+	if (i2c_check_functionality(client->adapter, I2C_FUNC_I2C) == 0) {
+		dev_dbg(&client->dev, "can't talk I2C?\n");
+		return -EIO;
+	}
+
+	for (i = 0; i < TWL4030_NUM_SLAVES; i++) {
+		if (twl4030_modules[i].inuse || twl4030_irq_base) {
+			dev_dbg(&client->dev, "driver is already in use\n");
+			return -EBUSY;
+		}
+	}
+
+	for (i = 0; i < TWL4030_NUM_SLAVES; i++) {
+		struct twl4030_client	*twl = &twl4030_modules[i];
+
+		if (i == 0)
+			twl->client = client;
+		else {
+			twl->client = i2c_new_dummy(client->adapter,
+					twl->address);
+			if (!twl->client) {
+				dev_err(&twl->client->dev,
+					"can't attach client %d\n", i);
+				status = -ENOMEM;
+				goto fail;
+			}
+			strlcpy(twl->client->name, id->name,
+					sizeof(twl->client->name));
+		}
+		twl->inuse = true;
+		mutex_init(&twl->xfer_lock);
+	}
+
+	status = add_children(pdata);
+	if (status < 0)
+		goto fail;
+
+	/*
+	 * Check if the PIH module is initialized, if yes, then init
+	 * the T2 Interrupt subsystem
+	 */
+	if (twl4030_modules[twl4030_map[TWL4030_MODULE_PIH].sid].inuse
+			&& twl4030_irq_base == 0
+			&& client->irq
+			&& pdata->irq_base
+			&& pdata->irq_end > pdata->irq_base)
+		twl_init_irq(client->irq, pdata->irq_base, pdata->irq_end);
+
+	dev_info(&client->dev, "chaining %d irqs\n",
+			twl4030_irq_base
+				? (pdata->irq_end - pdata->irq_base)
+				: 0);
+	return 0;
+
+fail:
+	twl4030_remove(client);
+	return status;
+}
+
+static const struct i2c_device_id twl4030_ids[] = {
+	{ "twl4030", 0 },	/* "Triton 2" */
+	{ "tps65950", 0 },	/* catalog version of twl4030 */
+	{ "tps65930", 0 },	/* fewer LDOs and DACs; no charger */
+	{ "tps65920", 0 },	/* fewer LDOs; no codec or charger */
+	{ /* end of list */ },
+};
+MODULE_DEVICE_TABLE(i2c, twl4030_ids);
+
+/* One Client Driver , 4 Clients */
+static struct i2c_driver twl4030_driver = {
+	.driver.name	= DRIVER_NAME,
+	.id_table	= twl4030_ids,
+	.probe		= twl4030_probe,
+	.remove		= twl4030_remove,
+};
+
 static int __init twl4030_init(void)
 {
 	return i2c_add_driver(&twl4030_driver);
 }
+subsys_initcall(twl4030_init);
 
 static void __exit twl4030_exit(void)
 {
 	i2c_del_driver(&twl4030_driver);
-	twl_irq_used = FREE;
 }
-
-subsys_initcall(twl4030_init);
 module_exit(twl4030_exit);
 
-MODULE_ALIAS("i2c:" DRIVER_NAME);
 MODULE_AUTHOR("Texas Instruments, Inc.");
 MODULE_DESCRIPTION("I2C Core interface for TWL4030");
 MODULE_LICENSE("GPL");

include/linux/i2c/twl4030.h

@@ -52,6 +52,17 @@
 #define TWL4030_MODULE_RTC		0x14
 #define TWL4030_MODULE_SECURED_REG	0x15
 
+struct twl4030_platform_data {
+	unsigned	irq_base, irq_end;
+
+	/* REVISIT more to come ... _nothing_ should be hard-wired */
+};
+
+/*
+ * FIXME completely stop using TWL4030_IRQ_BASE ... instead, pass the
+ * IRQ data to subsidiary devices using platform device resources.
+ */
+
 /* IRQ information-need base */
 #include <mach/irqs.h>
 /* TWL4030 interrupts */