[PATCH v6 2/4] i2c: pxa: Add support for the I2C units found in Armada 3700

[Romain Perier]

The Armada 3700 has two I2C controllers that is compliant with the I2C
Bus Specificiation 2.1, supports multi-master and different bus speed:
Standard mode (up to 100 KHz), Fast mode (up to 400 KHz),
High speed mode (up to 3.4 Mhz).

This IP block has a lot of similarity with the PXA, except some register
offsets and bitfield. This commits adds a basic support for this I2C
unit.

Signed-off-by: Romain Perier <romain.perier at free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
---

Changes in v6:
 - Revert back A3700_REGS, as asked by Wolfram and define fm_mask
   and hs_mask in the register layout. I moved the generic code
   for fm_mask and hs_mask to a seperated commit (1/4)

Changes in v5:
 - Don't define registers for armada-3700, we can re-use the ones
   for PXA3XX.
 - Define registers mask when OF is not used, in probe_pdata. 

Changes in v4:
 - Replaced the type of hs_mask and fm_mask by u32, instead of
   unsigned int, As writel() take an u32 as first argument...

Changes in v3:
 - Replaced the type of hs_mask and fm_mask by unsigned int,
   instead of unsigned long.

 drivers/i2c/busses/Kconfig   |  2 +-
 drivers/i2c/busses/i2c-pxa.c | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index d252276..2f56a26 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -763,7 +763,7 @@ config I2C_PUV3
 
 config I2C_PXA
 	tristate "Intel PXA2XX I2C adapter"
-	depends on ARCH_PXA || ARCH_MMP || (X86_32 && PCI && OF)
+	depends on ARCH_PXA || ARCH_MMP || ARCH_MVEBU || (X86_32 && PCI && OF)
 	help
 	  If you have devices in the PXA I2C bus, say yes to this option.
 	  This driver can also be built as a module.  If so, the module
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index dc9d0a6..0ded4bc 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -57,8 +57,12 @@ enum pxa_i2c_types {
 	REGS_PXA3XX,
 	REGS_CE4100,
 	REGS_PXA910,
+	REGS_A3700,
 };
 
+#define ICR_BUSMODE_FM	(1 << 16)	   /* shifted fast mode for armada-3700 */
+#define ICR_BUSMODE_HS	(1 << 17)	   /* shifted high speed mode for armada-3700 */
+
 /*
  * I2C registers definitions
  */
@@ -93,6 +97,15 @@ static struct pxa_reg_layout pxa_reg_layout[] = {
 		.ilcr = 0x28,
 		.iwcr = 0x30,
 	},
+	[REGS_A3700] = {
+		.ibmr =	0x00,
+		.idbr =	0x04,
+		.icr =	0x08,
+		.isr =	0x0c,
+		.isar =	0x10,
+		.fm = ICR_BUSMODE_FM,
+		.hs = ICR_BUSMODE_HS,
+	},
 };
 
 static const struct platform_device_id i2c_pxa_id_table[] = {
@@ -100,6 +113,7 @@ static const struct platform_device_id i2c_pxa_id_table[] = {
 	{ "pxa3xx-pwri2c",	REGS_PXA3XX },
 	{ "ce4100-i2c",		REGS_CE4100 },
 	{ "pxa910-i2c",		REGS_PXA910 },
+	{ "armada-3700-i2c",	REGS_A3700  },
 	{ },
 };
 MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
@@ -1141,6 +1155,7 @@ static const struct of_device_id i2c_pxa_dt_ids[] = {
 	{ .compatible = "mrvl,pxa-i2c", .data = (void *)REGS_PXA2XX },
 	{ .compatible = "mrvl,pwri2c", .data = (void *)REGS_PXA3XX },
 	{ .compatible = "mrvl,mmp-twsi", .data = (void *)REGS_PXA910 },
+	{ .compatible = "marvell,armada-3700-i2c", .data = (void *)REGS_A3700 },
 	{}
 };
 MODULE_DEVICE_TABLE(of, i2c_pxa_dt_ids);
-- 
2.9.3