i2c: designware-pci: Make bus number allocation robust

On some platforms, such as Intel Medfield, the I2C slave devices are enumerated
through SFI tables where bus numbering is expected to be defined in the OS.
Make the bus number allocation robust for such platforms.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-designware-core.h

@@ -26,6 +26,7 @@
 #define DW_IC_CON_MASTER		0x1
 #define DW_IC_CON_SPEED_STD		0x2
 #define DW_IC_CON_SPEED_FAST		0x4
+#define DW_IC_CON_SPEED_MASK		0x6
 #define DW_IC_CON_10BITADDR_MASTER	0x10
 #define DW_IC_CON_RESTART_EN		0x20
 #define DW_IC_CON_SLAVE_DISABLE		0x40

drivers/i2c/busses/i2c-designware-pcidrv.c

@@ -41,13 +41,7 @@
 #define DRIVER_NAME "i2c-designware-pci"
 
 enum dw_pci_ctl_id_t {
-	medfield_0,
-	medfield_1,
-	medfield_2,
-	medfield_3,
-	medfield_4,
-	medfield_5,
-
+	medfield,
 	baytrail,
 	haswell,
 };
@@ -68,6 +62,7 @@ struct dw_pci_controller {
 	u32 clk_khz;
 	u32 functionality;
 	struct dw_scl_sda_cfg *scl_sda_cfg;
+	int (*setup)(struct pci_dev *pdev, struct dw_pci_controller *c);
 };
 
 #define INTEL_MID_STD_CFG  (DW_IC_CON_MASTER |			\
@@ -98,48 +93,33 @@ static struct dw_scl_sda_cfg hsw_config = {
 	.sda_hold = 0x9,
 };
 
+static int mfld_setup(struct pci_dev *pdev, struct dw_pci_controller *c)
+{
+	switch (pdev->device) {
+	case 0x0817:
+		c->bus_cfg &= ~DW_IC_CON_SPEED_MASK;
+		c->bus_cfg |= DW_IC_CON_SPEED_STD;
+	case 0x0818:
+	case 0x0819:
+		c->bus_num = pdev->device - 0x817 + 3;
+		return 0;
+	case 0x082C:
+	case 0x082D:
+	case 0x082E:
+		c->bus_num = pdev->device - 0x82C + 0;
+		return 0;
+	}
+	return -ENODEV;
+}
+
 static struct dw_pci_controller dw_pci_controllers[] = {
-	[medfield_0] = {
-		.bus_num     = 0,
-		.bus_cfg   = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
-		.tx_fifo_depth = 32,
-		.rx_fifo_depth = 32,
-		.clk_khz      = 25000,
-	},
-	[medfield_1] = {
-		.bus_num     = 1,
-		.bus_cfg   = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
-		.tx_fifo_depth = 32,
-		.rx_fifo_depth = 32,
-		.clk_khz      = 25000,
-	},
-	[medfield_2] = {
-		.bus_num     = 2,
-		.bus_cfg   = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
-		.tx_fifo_depth = 32,
-		.rx_fifo_depth = 32,
-		.clk_khz      = 25000,
-	},
-	[medfield_3] = {
-		.bus_num     = 3,
-		.bus_cfg   = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_STD,
-		.tx_fifo_depth = 32,
-		.rx_fifo_depth = 32,
-		.clk_khz      = 25000,
-	},
-	[medfield_4] = {
-		.bus_num     = 4,
-		.bus_cfg   = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
-		.tx_fifo_depth = 32,
-		.rx_fifo_depth = 32,
-		.clk_khz      = 25000,
-	},
-	[medfield_5] = {
-		.bus_num     = 5,
+	[medfield] = {
+		.bus_num = -1,
 		.bus_cfg   = INTEL_MID_STD_CFG | DW_IC_CON_SPEED_FAST,
 		.tx_fifo_depth = 32,
 		.rx_fifo_depth = 32,
 		.clk_khz      = 25000,
+		.setup = mfld_setup,
 	},
 	[baytrail] = {
 		.bus_num = -1,
@@ -224,6 +204,13 @@ static int i2c_dw_pci_probe(struct pci_dev *pdev,
 	dev->base = pcim_iomap_table(pdev)[0];
 	dev->dev = &pdev->dev;
 	dev->irq = pdev->irq;
+
+	if (controller->setup) {
+		r = controller->setup(pdev, controller);
+		if (r)
+			return r;
+	}
+
 	dev->functionality = controller->functionality |
 				DW_DEFAULT_FUNCTIONALITY;
 
@@ -276,12 +263,12 @@ MODULE_ALIAS("i2c_designware-pci");
 
 static const struct pci_device_id i2_designware_pci_ids[] = {
 	/* Medfield */
-	{ PCI_VDEVICE(INTEL, 0x0817), medfield_3 },
-	{ PCI_VDEVICE(INTEL, 0x0818), medfield_4 },
-	{ PCI_VDEVICE(INTEL, 0x0819), medfield_5 },
-	{ PCI_VDEVICE(INTEL, 0x082C), medfield_0 },
-	{ PCI_VDEVICE(INTEL, 0x082D), medfield_1 },
-	{ PCI_VDEVICE(INTEL, 0x082E), medfield_2 },
+	{ PCI_VDEVICE(INTEL, 0x0817), medfield },
+	{ PCI_VDEVICE(INTEL, 0x0818), medfield },
+	{ PCI_VDEVICE(INTEL, 0x0819), medfield },
+	{ PCI_VDEVICE(INTEL, 0x082C), medfield },
+	{ PCI_VDEVICE(INTEL, 0x082D), medfield },
+	{ PCI_VDEVICE(INTEL, 0x082E), medfield },
 	/* Baytrail */
 	{ PCI_VDEVICE(INTEL, 0x0F41), baytrail },
 	{ PCI_VDEVICE(INTEL, 0x0F42), baytrail },