sunxi: i2c: Add support for DM I2C

This commit adds support for DM I2C on sunxi platform. It can coexist
with old style sunxi I2C driver, because it is still used in SPL and
by some SoCs.

Because sunxi platform doesn't yet support DM clk, reset and pinctrl
driver, workaround is needed to enable clocks and set resets and
pinctrls. This is done by calling i2c_init_board() in board_init().
This means that CONFIG_I2Cx_ENABLE options needs to be correctly set
in order to use needed I2C controller.

Commit is based on the previous patch made by Philipp Tomsich

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/mach-sunxi/board.c

@@ -204,7 +204,9 @@ void s_init(void)
 	clock_init();
 	timer_init();
 	gpio_init();
+#ifndef CONFIG_DM_I2C
 	i2c_init_board();
+#endif
 	eth_init_board();
 }
 

board/sunxi/board.c

@@ -222,6 +222,14 @@ int board_init(void)
 	gpio_direction_output(macpwr_pin, 1);
 #endif
 
+#ifdef CONFIG_DM_I2C
+	/*
+	 * Temporary workaround for enabling I2C clocks until proper sunxi DM
+	 * clk, reset and pinctrl drivers land.
+	 */
+	i2c_init_board();
+#endif
+
 	/* Uses dm gpio code so do this here and not in i2c_init_board() */
 	return soft_i2c_board_init();
 }

drivers/i2c/mvtwsi.c

@@ -36,6 +36,14 @@ DECLARE_GLOBAL_DATA_PTR;
 #endif
 #endif /* CONFIG_DM_I2C */
 
+/*
+ * On SUNXI, we get CONFIG_SYS_TCLK from this include, so we want to
+ * always have it.
+ */
+#if defined(CONFIG_DM_I2C) && defined(CONFIG_ARCH_SUNXI)
+#include <asm/arch/i2c.h>
+#endif
+
 /*
  * TWSI register structure
  */
@@ -831,6 +839,7 @@ static const struct dm_i2c_ops mvtwsi_i2c_ops = {
 static const struct udevice_id mvtwsi_i2c_ids[] = {
 	{ .compatible = "marvell,mv64xxx-i2c", },
 	{ .compatible = "marvell,mv78230-i2c", },
+	{ .compatible = "allwinner,sun6i-a31-i2c", },
 	{ /* sentinel */ }
 };
 

include/configs/sunxi-common.h

@@ -211,11 +211,13 @@
 #if defined CONFIG_I2C0_ENABLE || defined CONFIG_I2C1_ENABLE || \
     defined CONFIG_I2C2_ENABLE || defined CONFIG_I2C3_ENABLE || \
     defined CONFIG_I2C4_ENABLE || defined CONFIG_R_I2C_ENABLE
-#define CONFIG_SYS_I2C
 #define CONFIG_SYS_I2C_MVTWSI
+#ifndef CONFIG_DM_I2C
+#define CONFIG_SYS_I2C
 #define CONFIG_SYS_I2C_SPEED		400000
 #define CONFIG_SYS_I2C_SLAVE		0x7f
 #endif
+#endif
 
 #if defined CONFIG_VIDEO_LCD_PANEL_I2C && !(defined CONFIG_SPL_BUILD)
 #define CONFIG_SYS_I2C_SOFT