Add hotplug support to mcp251x driver

Chip model can now be selected directly by matching the modalias name
(instead of filling the .model field in platform_data), and allows the
module to be auto-loaded. Previous behaviour is of course still supported.

Convert the two in-tree users to this feature (icontrol & zeus).
Tested on an Zeus platform (mcp2515).

Signed-off-by: Marc Zyngier <maz@misterjones.org>
Acked-by: Christian Pellegrin <chripell@fsfe.org>
Cc: Edwin Peer <epeer@tmtservices.co.za>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/arm/mach-pxa/icontrol.c

@@ -73,7 +73,6 @@ static struct pxa2xx_spi_chip mcp251x_chip_info4 = {
 
 static struct mcp251x_platform_data mcp251x_info = {
 	.oscillator_frequency = 16E6,
-	.model                = CAN_MCP251X_MCP2515,
 	.board_specific_setup = NULL,
 	.power_enable         = NULL,
 	.transceiver_enable   = NULL
@@ -81,7 +80,7 @@ static struct mcp251x_platform_data mcp251x_info = {
 
 static struct spi_board_info mcp251x_board_info[] = {
 	{
-		.modalias        = "mcp251x",
+		.modalias        = "mcp2515",
 		.max_speed_hz    = 6500000,
 		.bus_num         = 3,
 		.chip_select     = 0,
@@ -90,7 +89,7 @@ static struct spi_board_info mcp251x_board_info[] = {
 		.irq             = gpio_to_irq(ICONTROL_MCP251x_nIRQ1)
 	},
 	{
-		.modalias        = "mcp251x",
+		.modalias        = "mcp2515",
 		.max_speed_hz    = 6500000,
 		.bus_num         = 3,
 		.chip_select     = 1,
@@ -99,7 +98,7 @@ static struct spi_board_info mcp251x_board_info[] = {
 		.irq             = gpio_to_irq(ICONTROL_MCP251x_nIRQ2)
 	},
 	{
-		.modalias        = "mcp251x",
+		.modalias        = "mcp2515",
 		.max_speed_hz    = 6500000,
 		.bus_num         = 4,
 		.chip_select     = 0,
@@ -108,7 +107,7 @@ static struct spi_board_info mcp251x_board_info[] = {
 		.irq             = gpio_to_irq(ICONTROL_MCP251x_nIRQ3)
 	},
 	{
-		.modalias        = "mcp251x",
+		.modalias        = "mcp2515",
 		.max_speed_hz    = 6500000,
 		.bus_num         = 4,
 		.chip_select     = 1,

arch/arm/mach-pxa/zeus.c

@@ -414,15 +414,13 @@ static int zeus_mcp2515_transceiver_enable(int enable)
 
 static struct mcp251x_platform_data zeus_mcp2515_pdata = {
 	.oscillator_frequency	= 16*1000*1000,
-	.model			= CAN_MCP251X_MCP2515,
 	.board_specific_setup	= zeus_mcp2515_setup,
-	.transceiver_enable	= zeus_mcp2515_transceiver_enable,
 	.power_enable		= zeus_mcp2515_transceiver_enable,
 };
 
 static struct spi_board_info zeus_spi_board_info[] = {
 	[0] = {
-		.modalias	= "mcp251x",
+		.modalias	= "mcp2515",
 		.platform_data	= &zeus_mcp2515_pdata,
 		.irq		= gpio_to_irq(ZEUS_CAN_GPIO),
 		.max_speed_hz	= 1*1000*1000,

drivers/net/can/mcp251x.c

@@ -922,12 +922,16 @@ static int __devinit mcp251x_can_probe(struct spi_device *spi)
 	struct net_device *net;
 	struct mcp251x_priv *priv;
 	struct mcp251x_platform_data *pdata = spi->dev.platform_data;
+	int model = spi_get_device_id(spi)->driver_data;
 	int ret = -ENODEV;
 
 	if (!pdata)
 		/* Platform data is required for osc freq */
 		goto error_out;
 
+	if (model)
+		pdata->model = model;
+
 	/* Allocate can/net device */
 	net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX);
 	if (!net) {
@@ -1117,6 +1121,15 @@ static int mcp251x_can_resume(struct spi_device *spi)
 #define mcp251x_can_resume NULL
 #endif
 
+static struct spi_device_id mcp251x_id_table[] = {
+	{ "mcp251x", 	0 /* Use pdata.model */ },
+	{ "mcp2510",	CAN_MCP251X_MCP2510 },
+	{ "mcp2515",	CAN_MCP251X_MCP2515 },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
+
 static struct spi_driver mcp251x_can_driver = {
 	.driver = {
 		.name = DEVICE_NAME,
@@ -1124,6 +1137,7 @@ static struct spi_driver mcp251x_can_driver = {
 		.owner = THIS_MODULE,
 	},
 
+	.id_table = mcp251x_id_table,
 	.probe = mcp251x_can_probe,
 	.remove = __devexit_p(mcp251x_can_remove),
 	.suspend = mcp251x_can_suspend,

include/linux/can/platform/mcp251x.h

@@ -26,8 +26,8 @@
 struct mcp251x_platform_data {
 	unsigned long oscillator_frequency;
 	int model;
-#define CAN_MCP251X_MCP2510 0
-#define CAN_MCP251X_MCP2515 1
+#define CAN_MCP251X_MCP2510 0x2510
+#define CAN_MCP251X_MCP2515 0x2515
 	int (*board_specific_setup)(struct spi_device *spi);
 	int (*transceiver_enable)(int enable);
 	int (*power_enable) (int enable);