[RFC PATCH v1 1/2] dm: i2c: allow disabling driver model in SPL

[Igor Opaniuk]

From: Igor Opaniuk <igor.opaniuk at foundries.io>

At present if U-Boot proper uses driver model for I2C, then SPL has to
also. While this is desirable, it places a significant barrier to moving
to driver model in some cases. For example, with a space-constrained SPL
it may be necessary to enable CONFIG_SPL_OF_PLATDATA which involves
adjusting some drivers.

This patch introduces a separate Kconfig symbols for enabling DM_I2C and
DM_I2C_GPIO support in SPL.

This will also help to get away from dirty workarounds to
achieve non-DM I2C support for SPL, which is currently used in some
board header files like:

ifdef CONFIG_SPL_BUILD
undef CONFIG_DM_I2C
endif

Signed-off-by: Igor Opaniuk <igor.opaniuk at foundries.io>
---

 drivers/i2c/Kconfig   | 21 +++++++++++++++++++++
 drivers/i2c/Makefile  |  4 ++--
 drivers/misc/Makefile |  2 +-
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index 403602fddf..5fce14122d 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -14,6 +14,17 @@ config DM_I2C
 	  device (bus child) info is kept as parent plat. The interface
 	  is defined in include/i2c.h.
 
+config SPL_DM_I2C
+	bool "Enable Driver Model for I2C drivers in SPL"
+	depends on SPL_DM && DM_I2C
+	default y
+	help
+	  Enable driver model for I2C. The I2C uclass interface: probe, read,
+	  write and speed, is implemented with the bus drivers operations,
+	  which provide methods for bus setting and data transfer. Each chip
+	  device (bus child) info is kept as parent platdata. The interface
+	  is defined in include/i2c.h.
+
 config I2C_CROS_EC_TUNNEL
 	tristate "Chrome OS EC tunnel I2C bus"
 	depends on CROS_EC
@@ -61,6 +72,16 @@ config DM_I2C_GPIO
 	  bindings are supported.
 	  Binding info: doc/device-tree-bindings/i2c/i2c-gpio.txt
 
+config SPL_DM_I2C_GPIO
+	bool "Enable Driver Model for software emulated I2C bus driver in SPL"
+	depends on SPL_DM && DM_I2C_GPIO && SPL_DM_GPIO && SPL_GPIO_SUPPORT
+	default y
+	help
+	  Enable the i2c bus driver emulation by using the GPIOs. The bus GPIO
+	  configuration is given by the device tree. Kernel-style device tree
+	  bindings are supported.
+	  Binding info: doc/device-tree-bindings/i2c/i2c-gpio.txt
+
 config SYS_I2C_AT91
 	bool "Atmel I2C driver"
 	depends on DM_I2C && ARCH_AT91
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index 29aab0f9e3..acd27ac29d 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -2,9 +2,9 @@
 #
 # (C) Copyright 2000-2007
 # Wolfgang Denk, DENX Software Engineering, wd at denx.de.
-obj-$(CONFIG_DM_I2C) += i2c-uclass.o
+obj-$(CONFIG_$(SPL_)DM_I2C) += i2c-uclass.o
 ifdef CONFIG_ACPIGEN
-obj-$(CONFIG_DM_I2C) += acpi_i2c.o
+obj-$(CONFIG_$(SPL_)DM_I2C) += acpi_i2c.o
 endif
 obj-$(CONFIG_$(SPL_)DM_I2C_GPIO) += i2c-gpio.o
 obj-$(CONFIG_$(SPL_)I2C_CROS_EC_TUNNEL) += cros_ec_tunnel.o
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index d737203704..1a49396007 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -17,7 +17,7 @@ obj-$(CONFIG_SANDBOX) += p2sb_sandbox.o p2sb_emul.o
 obj-$(CONFIG_SANDBOX) += swap_case.o
 endif
 
-ifdef CONFIG_DM_I2C
+ifdef CONFIG_$(SPL_)DM_I2C
 ifndef CONFIG_SPL_BUILD
 obj-$(CONFIG_SANDBOX) += i2c_eeprom_emul.o
 endif
-- 
2.25.1