i2c: aspeed: add buffer mode transfer support

Byte mode currently this driver uses makes lots of interrupt call
which isn't good for performance and it makes the driver very
timing sensitive. To improve performance of the driver, this commit
adds buffer mode transfer support which uses I2C SRAM buffer
instead of using a single byte buffer.

AST2400:
It has 2 KBytes (256 Bytes x 8 pages) of I2C SRAM buffer pool from
0x1e78a800 to 0x1e78afff that can be used for all busses with
buffer pool manipulation. To simplify implementation for supporting
both AST2400 and AST2500, it assigns each 128 Bytes per bus without
using buffer pool manipulation so total 1792 Bytes of I2C SRAM
buffer will be used.

AST2500:
It has 16 Bytes of individual I2C SRAM buffer per each bus and its
range is from 0x1e78a200 to 0x1e78a2df, so it doesn't have 'buffer
page selection' bit field in the Function control register, and
neither 'base address pointer' bit field in the Pool buffer control
register it has. To simplify implementation for supporting both
AST2400 and AST2500, it writes zeros on those register bit fields
but it's okay because it does nothing in AST2500.

It provides buffer based master and slave data transfer.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@intel.com>

1 files changed, 28 insertions, 19 deletions

diff --git a/arch/arm/boot/dts/aspeed-g5.dtsi b/arch/arm/boot/dts/aspeed-g5.dtsi
index 73922784eee5..08e97c0d3f78 100644
--- a/arch/arm/boot/dts/aspeed-g5.dtsi
+++ b/arch/arm/boot/dts/aspeed-g5.dtsi
@@ -617,12 +617,21 @@
 };
 
 &i2c {
-	i2c_ic: interrupt-controller@0 {
-		#interrupt-cells = <1>;
-		compatible = "aspeed,ast2500-i2c-ic";
+	i2c_gr: i2c-global-regs@0 {
+		compatible = "aspeed,ast2500-i2c-gr", "syscon";
 		reg = <0x0 0x40>;
-		interrupts = <12>;
-		interrupt-controller;
+
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges = <0x0 0x0 0x40>;
+
+		i2c_ic: interrupt-controller@0 {
+			#interrupt-cells = <1>;
+			compatible = "aspeed,ast2500-i2c-ic";
+			reg = <0x0 0x4>;
+			interrupts = <12>;
+			interrupt-controller;
+		};
 	};
 
 	i2c0: i2c-bus@40 {
@@ -630,7 +639,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x40 0x40>;
+		reg = <0x40 0x40>, <0x200 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -646,7 +655,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x80 0x40>;
+		reg = <0x80 0x40>, <0x210 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -662,7 +671,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0xc0 0x40>;
+		reg = <0xc0 0x40>, <0x220 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -679,7 +688,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x100 0x40>;
+		reg = <0x100 0x40>, <0x230 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -696,7 +705,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x140 0x40>;
+		reg = <0x140 0x40>, <0x240 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -713,7 +722,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x180 0x40>;
+		reg = <0x180 0x40>, <0x250 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -730,7 +739,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x1c0 0x40>;
+		reg = <0x1c0 0x40>, <0x260 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -747,7 +756,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x300 0x40>;
+		reg = <0x300 0x40>, <0x270 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -764,7 +773,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x340 0x40>;
+		reg = <0x340 0x40>, <0x280 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -781,7 +790,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x380 0x40>;
+		reg = <0x380 0x40>, <0x290 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -798,7 +807,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x3c0 0x40>;
+		reg = <0x3c0 0x40>, <0x2a0 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -815,7 +824,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x400 0x40>;
+		reg = <0x400 0x40>, <0x2b0 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -832,7 +841,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x440 0x40>;
+		reg = <0x440 0x40>, <0x2c0 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;
@@ -849,7 +858,7 @@
 		#size-cells = <0>;
 		#interrupt-cells = <1>;
 
-		reg = <0x480 0x40>;
+		reg = <0x480 0x40>, <0x2d0 0x10>;
 		compatible = "aspeed,ast2500-i2c-bus";
 		clocks = <&syscon ASPEED_CLK_APB>;
 		resets = <&syscon ASPEED_RESET_I2C>;