Merge tag 'arm-soc/for-3.19/brcmstb-drivers' of https://github.com/brcm/linux into next/drivers

This pull request contains the following changes to the Broadcom GISB bus
arbiter from Kevin Cernekee:

- Extend brcmstb GISB bus driver to work on MIPS (currently ARM-only) and support
  65nm and 40nm MIPS-based chips such as: BCM7038, BCM7400 and BCM7435

* tag 'arm-soc/for-3.19/brcmstb-drivers' of https://github.com/brcm/linux:
  bus: brcmstb_gisb: Add register offset tables for older chips
  bus: brcmstb_gisb: Look up register offsets in a table
  bus: brcmstb_gisb: Introduce wrapper functions for MMIO accesses
  bus: brcmstb_gisb: Make the driver buildable on MIPS

Conflicts:
	drivers/bus/brcmstb_gisb.c

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

2 files changed, 100 insertions, 20 deletions

diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 603eb1be4f6..b99729e3686 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -6,7 +6,7 @@ menu "Bus devices"
 
 config BRCMSTB_GISB_ARB
 	bool "Broadcom STB GISB bus arbiter"
-	depends on ARM
+	depends on ARM || MIPS
 	help
 	  Driver for the Broadcom Set Top Box System-on-a-chip internal bus
 	  arbiter. This driver provides timeout and target abort error handling
diff --git a/drivers/bus/brcmstb_gisb.c b/drivers/bus/brcmstb_gisb.c
index b801234dfc0..bfd40f11e92 100644
--- a/drivers/bus/brcmstb_gisb.c
+++ b/drivers/bus/brcmstb_gisb.c
@@ -24,26 +24,72 @@
 #include <linux/of.h>
 #include <linux/bitops.h>
 
+#ifdef CONFIG_ARM
 #include <asm/bug.h>
 #include <asm/signal.h>
+#endif
 
-#define ARB_TIMER			0x008
-#define ARB_ERR_CAP_CLR			0x7e4
 #define  ARB_ERR_CAP_CLEAR		(1 << 0)
-#define ARB_ERR_CAP_HI_ADDR		0x7e8
-#define ARB_ERR_CAP_ADDR		0x7ec
-#define ARB_ERR_CAP_DATA		0x7f0
-#define ARB_ERR_CAP_STATUS		0x7f4
 #define  ARB_ERR_CAP_STATUS_TIMEOUT	(1 << 12)
 #define  ARB_ERR_CAP_STATUS_TEA		(1 << 11)
 #define  ARB_ERR_CAP_STATUS_BS_SHIFT	(1 << 2)
 #define  ARB_ERR_CAP_STATUS_BS_MASK	0x3c
 #define  ARB_ERR_CAP_STATUS_WRITE	(1 << 1)
 #define  ARB_ERR_CAP_STATUS_VALID	(1 << 0)
-#define ARB_ERR_CAP_MASTER		0x7f8
+
+enum {
+	ARB_TIMER,
+	ARB_ERR_CAP_CLR,
+	ARB_ERR_CAP_HI_ADDR,
+	ARB_ERR_CAP_ADDR,
+	ARB_ERR_CAP_DATA,
+	ARB_ERR_CAP_STATUS,
+	ARB_ERR_CAP_MASTER,
+};
+
+static const int gisb_offsets_bcm7038[] = {
+	[ARB_TIMER]		= 0x00c,
+	[ARB_ERR_CAP_CLR]	= 0x0c4,
+	[ARB_ERR_CAP_HI_ADDR]	= -1,
+	[ARB_ERR_CAP_ADDR]	= 0x0c8,
+	[ARB_ERR_CAP_DATA]	= 0x0cc,
+	[ARB_ERR_CAP_STATUS]	= 0x0d0,
+	[ARB_ERR_CAP_MASTER]	= -1,
+};
+
+static const int gisb_offsets_bcm7400[] = {
+	[ARB_TIMER]		= 0x00c,
+	[ARB_ERR_CAP_CLR]	= 0x0c8,
+	[ARB_ERR_CAP_HI_ADDR]	= -1,
+	[ARB_ERR_CAP_ADDR]	= 0x0cc,
+	[ARB_ERR_CAP_DATA]	= 0x0d0,
+	[ARB_ERR_CAP_STATUS]	= 0x0d4,
+	[ARB_ERR_CAP_MASTER]	= 0x0d8,
+};
+
+static const int gisb_offsets_bcm7435[] = {
+	[ARB_TIMER]		= 0x00c,
+	[ARB_ERR_CAP_CLR]	= 0x168,
+	[ARB_ERR_CAP_HI_ADDR]	= -1,
+	[ARB_ERR_CAP_ADDR]	= 0x16c,
+	[ARB_ERR_CAP_DATA]	= 0x170,
+	[ARB_ERR_CAP_STATUS]	= 0x174,
+	[ARB_ERR_CAP_MASTER]	= 0x178,
+};
+
+static const int gisb_offsets_bcm7445[] = {
+	[ARB_TIMER]		= 0x008,
+	[ARB_ERR_CAP_CLR]	= 0x7e4,
+	[ARB_ERR_CAP_HI_ADDR]	= 0x7e8,
+	[ARB_ERR_CAP_ADDR]	= 0x7ec,
+	[ARB_ERR_CAP_DATA]	= 0x7f0,
+	[ARB_ERR_CAP_STATUS]	= 0x7f4,
+	[ARB_ERR_CAP_MASTER]	= 0x7f8,
+};
 
 struct brcmstb_gisb_arb_device {
 	void __iomem	*base;
+	const int	*gisb_offsets;
 	struct mutex	lock;
 	struct list_head next;
 	u32 valid_mask;
@@ -52,6 +98,26 @@ struct brcmstb_gisb_arb_device {
 
 static LIST_HEAD(brcmstb_gisb_arb_device_list);
 
+static u32 gisb_read(struct brcmstb_gisb_arb_device *gdev, int reg)
+{
+	int offset = gdev->gisb_offsets[reg];
+
+	/* return 1 if the hardware doesn't have ARB_ERR_CAP_MASTER */
+	if (offset == -1)
+		return 1;
+
+	return ioread32(gdev->base + offset);
+}
+
+static void gisb_write(struct brcmstb_gisb_arb_device *gdev, u32 val, int reg)
+{
+	int offset = gdev->gisb_offsets[reg];
+
+	if (offset == -1)
+		return;
+	iowrite32(val, gdev->base + reg);
+}
+
 static ssize_t gisb_arb_get_timeout(struct device *dev,
 				    struct device_attribute *attr,
 				    char *buf)
@@ -61,7 +127,7 @@ static ssize_t gisb_arb_get_timeout(struct device *dev,
 	u32 timeout;
 
 	mutex_lock(&gdev->lock);
-	timeout = ioread32(gdev->base + ARB_TIMER);
+	timeout = gisb_read(gdev, ARB_TIMER);
 	mutex_unlock(&gdev->lock);
 
 	return sprintf(buf, "%d", timeout);
@@ -83,7 +149,7 @@ static ssize_t gisb_arb_set_timeout(struct device *dev,
 		return -EINVAL;
 
 	mutex_lock(&gdev->lock);
-	iowrite32(val, gdev->base + ARB_TIMER);
+	gisb_write(gdev, val, ARB_TIMER);
 	mutex_unlock(&gdev->lock);
 
 	return count;
@@ -110,18 +176,18 @@ static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
 	const char *m_name;
 	char m_fmt[11];
 
-	cap_status = ioread32(gdev->base + ARB_ERR_CAP_STATUS);
+	cap_status = gisb_read(gdev, ARB_ERR_CAP_STATUS);
 
 	/* Invalid captured address, bail out */
 	if (!(cap_status & ARB_ERR_CAP_STATUS_VALID))
 		return 1;
 
 	/* Read the address and master */
-	arb_addr = ioread32(gdev->base + ARB_ERR_CAP_ADDR) & 0xffffffff;
+	arb_addr = gisb_read(gdev, ARB_ERR_CAP_ADDR) & 0xffffffff;
 #if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT))
-	arb_addr |= (u64)ioread32(gdev->base + ARB_ERR_CAP_HI_ADDR) << 32;
+	arb_addr |= (u64)gisb_read(gdev, ARB_ERR_CAP_HI_ADDR) << 32;
 #endif
-	master = ioread32(gdev->base + ARB_ERR_CAP_MASTER);
+	master = gisb_read(gdev, ARB_ERR_CAP_MASTER);
 
 	m_name = brcmstb_gisb_master_to_str(gdev, master);
 	if (!m_name) {
@@ -136,11 +202,12 @@ static int brcmstb_gisb_arb_decode_addr(struct brcmstb_gisb_arb_device *gdev,
 		m_name);
 
 	/* clear the GISB error */
-	iowrite32(ARB_ERR_CAP_CLEAR, gdev->base + ARB_ERR_CAP_CLR);
+	gisb_write(gdev, ARB_ERR_CAP_CLEAR, ARB_ERR_CAP_CLR);
 
 	return 0;
 }
 
+#ifdef CONFIG_ARM
 static int brcmstb_bus_error_handler(unsigned long addr, unsigned int fsr,
 				     struct pt_regs *regs)
 {
@@ -165,6 +232,7 @@ void __init brcmstb_hook_fault_code(void)
 	hook_fault_code(22, brcmstb_bus_error_handler, SIGBUS, 0,
 			"imprecise external abort");
 }
+#endif
 
 static irqreturn_t brcmstb_gisb_timeout_handler(int irq, void *dev_id)
 {
@@ -192,10 +260,20 @@ static struct attribute_group gisb_arb_sysfs_attr_group = {
 	.attrs = gisb_arb_sysfs_attrs,
 };
 
+static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
+	{ .compatible = "brcm,gisb-arb",         .data = gisb_offsets_bcm7445 },
+	{ .compatible = "brcm,bcm7445-gisb-arb", .data = gisb_offsets_bcm7445 },
+	{ .compatible = "brcm,bcm7435-gisb-arb", .data = gisb_offsets_bcm7435 },
+	{ .compatible = "brcm,bcm7400-gisb-arb", .data = gisb_offsets_bcm7400 },
+	{ .compatible = "brcm,bcm7038-gisb-arb", .data = gisb_offsets_bcm7038 },
+	{ },
+};
+
 static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
 {
 	struct device_node *dn = pdev->dev.of_node;
 	struct brcmstb_gisb_arb_device *gdev;
+	const struct of_device_id *of_id;
 	struct resource *r;
 	int err, timeout_irq, tea_irq;
 	unsigned int num_masters, j = 0;
@@ -216,6 +294,13 @@ static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
 	if (IS_ERR(gdev->base))
 		return PTR_ERR(gdev->base);
 
+	of_id = of_match_node(brcmstb_gisb_arb_of_match, dn);
+	if (!of_id) {
+		pr_err("failed to look up compatible string\n");
+		return -EINVAL;
+	}
+	gdev->gisb_offsets = of_id->data;
+
 	err = devm_request_irq(&pdev->dev, timeout_irq,
 				brcmstb_gisb_timeout_handler, 0, pdev->name,
 				gdev);
@@ -267,11 +352,6 @@ static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id brcmstb_gisb_arb_of_match[] = {
-	{ .compatible = "brcm,gisb-arb" },
-	{ },
-};
-
 static struct platform_driver brcmstb_gisb_arb_driver = {
 	.driver = {
 		.name	= "brcm-gisb-arb",