firmware: arm_scmi: Fix i.MX build dependency

The newly added SCMI vendor driver references functions in the
protocol driver but needs a Kconfig dependency to ensure it can link,
essentially the Kconfig dependency needs to be reversed to match the
link time dependency:

  |  arm-linux-gnueabi-ld: sound/soc/fsl/fsl_mqs.o: in function `fsl_mqs_sm_write':
  |  	fsl_mqs.c:(.text+0x1aa): undefined reference to `scmi_imx_misc_ctrl_set'
  |  arm-linux-gnueabi-ld: sound/soc/fsl/fsl_mqs.o: in function `fsl_mqs_sm_read':
  |  	fsl_mqs.c:(.text+0x1ee): undefined reference to `scmi_imx_misc_ctrl_get'

This however only works after changing the dependency in the SND_SOC_FSL_MQS
driver as well, which uses 'select IMX_SCMI_MISC_DRV' to turn on a
driver it depends on. This is generally a bad idea, so the best solution
is to change that into a dependency.

To allow the ASoC driver to keep building with the SCMI support, this
needs to be an optional dependency that enforces the link-time
dependency if IMX_SCMI_MISC_DRV is a loadable module but not
depend on it if that is disabled.

Fixes: 61c9f03 ("firmware: arm_scmi: Add initial support for i.MX MISC protocol")
Fixes: 101c902 ("ASoC: fsl_mqs: Support accessing registers by scmi interface")
Signed-off-by: Arnd Bergmann <[email protected]>
Acked-by: Mark Brown <[email protected]>
Acked-by: Shengjiu Wang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Sudeep Holla <[email protected]>

Author: arndb

drivers/firmware/arm_scmi/vendors/imx/Kconfig

@@ -15,6 +15,7 @@ config IMX_SCMI_BBM_EXT
 config IMX_SCMI_MISC_EXT
 	tristate "i.MX SCMI MISC EXTENSION"
 	depends on ARM_SCMI_PROTOCOL || (COMPILE_TEST && OF)
+	depends on IMX_SCMI_MISC_DRV
 	default y if ARCH_MXC
 	help
 	  This enables i.MX System MISC control logic such as gpio expander

drivers/firmware/imx/Kconfig

@@ -25,7 +25,6 @@ config IMX_SCU
 
 config IMX_SCMI_MISC_DRV
 	tristate "IMX SCMI MISC Protocol driver"
-	depends on IMX_SCMI_MISC_EXT || COMPILE_TEST
 	default y if ARCH_MXC
 	help
 	  The System Controller Management Interface firmware (SCMI FW) is

sound/soc/fsl/Kconfig

@@ -29,8 +29,8 @@ config SND_SOC_FSL_SAI
 config SND_SOC_FSL_MQS
 	tristate "Medium Quality Sound (MQS) module support"
 	depends on SND_SOC_FSL_SAI
+	depends on IMX_SCMI_MISC_DRV || !IMX_SCMI_MISC_DRV
 	select REGMAP_MMIO
-	select IMX_SCMI_MISC_DRV if IMX_SCMI_MISC_EXT !=n
 	help
 	  Say Y if you want to add Medium Quality Sound (MQS)
 	  support for the Freescale CPUs.