linux-raspberrypi: use fragments for device specific configuration

Using fragments allows to reuse configuration amongst sibling kernels.

Change-type: patch
Signed-off-by: Alex Gonzalez <alexg@balena.io>

Author: alexgg

layers/meta-balena-raspberrypi/recipes-kernel/linux/files/balena-os-drivers.cfg

@@ -0,0 +1,93 @@
+# Drivers and helpers enabled on top of the upstream raspberrypi defconfig for
+# balenaOS. Picked up by kernel-balena's do_kernel_balena_merge_fragments (via
+# FILESEXTRAPATHS), so it applies to both linux-raspberrypi (the OS kernel) and
+# linux-raspberrypi-extension without duplication.
+#
+# Machine-conditional entries (optimize-size for rpi3-64/rpi4-64, pieeprom for
+# rpi4-64) remain in BALENA_CONFIGS in the bbappend — they're easier to keep
+# behind :append:<machine> overrides than to express in a flat fragment.
+
+# fbtft framebuffers
+CONFIG_STAGING=y
+CONFIG_FB_TFT=m
+CONFIG_FB_TFT_AGM1264K_FL=m
+CONFIG_FB_TFT_BD663474=m
+CONFIG_FB_TFT_HX8340BN=m
+CONFIG_FB_TFT_HX8347D=m
+CONFIG_FB_TFT_HX8353D=m
+CONFIG_FB_TFT_ILI9163=m
+CONFIG_FB_TFT_ILI9320=m
+CONFIG_FB_TFT_ILI9325=m
+CONFIG_FB_TFT_ILI9340=m
+CONFIG_FB_TFT_ILI9341=m
+CONFIG_FB_TFT_ILI9481=m
+CONFIG_FB_TFT_ILI9486=m
+CONFIG_FB_TFT_PCD8544=m
+CONFIG_FB_TFT_RA8875=m
+CONFIG_FB_TFT_S6D02A1=m
+CONFIG_FB_TFT_S6D1121=m
+CONFIG_FB_TFT_SSD1289=m
+CONFIG_FB_TFT_SSD1306=m
+CONFIG_FB_TFT_SSD1331=m
+CONFIG_FB_TFT_SSD1351=m
+CONFIG_FB_TFT_ST7735R=m
+CONFIG_FB_TFT_TINYLCD=m
+CONFIG_FB_TFT_TLS8204=m
+CONFIG_FB_TFT_UC1701=m
+CONFIG_FB_TFT_UPD161704=m
+CONFIG_FB_TFT_WATTEROTT=m
+
+# pca955 GPIO expander
+CONFIG_GPIO_PCA953X=y
+CONFIG_GPIO_PCA953X_IRQ=y
+
+# Kontron PLD (gpio_i2c_kempld) — deps + leaf modules
+CONFIG_GPIOLIB=y
+CONFIG_I2C=y
+CONFIG_HAS_IOMEM=y
+CONFIG_MFD_KEMPLD=m
+CONFIG_GPIO_KEMPLD=m
+CONFIG_I2C_KEMPLD=m
+
+# RPi watchdog
+CONFIG_WATCHDOG=y
+CONFIG_BCM2835_WDT=y
+
+# Kvaser USB CAN driver
+CONFIG_CAN_KVASER_USB=m
+
+# MCP251x CAN driver — deps + leaf module
+CONFIG_SPI=y
+CONFIG_HAS_DMA=y
+CONFIG_CAN_MCP251X=m
+
+# CAN bit timing
+CONFIG_CAN_DEV=y
+CONFIG_CAN_CALC_BITTIMING=y
+
+# DS1307 RTC
+CONFIG_RTC_DRV_DS1307=m
+
+# SC16IS7xx serial
+CONFIG_SERIAL_SC16IS7XX=m
+
+# MCP3422 ADC
+CONFIG_MCP3422=m
+
+# SD8787 PWRSEQ — deps + leaf module
+CONFIG_OF=y
+CONFIG_PWRSEQ_SD8787=m
+
+# 8250 serial
+CONFIG_SERIAL_8250=y
+CONFIG_SERIAL_8250_CONSOLE=y
+CONFIG_SERIAL_8250_NR_UARTS=1
+CONFIG_SERIAL_8250_EXTENDED=y
+CONFIG_SERIAL_8250_SHARE_IRQ=y
+CONFIG_SERIAL_8250_BCM2835AUX=y
+
+# IIO pressure drivers
+CONFIG_BMP280=m
+
+# Realtek RTL8192CU WiFi
+CONFIG_RTL8192CU=m

layers/meta-balena-raspberrypi/recipes-kernel/linux/linux-raspberrypi_%.bbappend

@@ -46,8 +46,3 @@ BALENA_CONFIGS[pieeprom] = " \
     CONFIG_SPI_BCM2835=y \
     CONFIG_SPI_SPIDEV=y \
 "
-
-BALENA_CONFIGS:append = " rtl8192"
-BALENA_CONFIGS[rtl8192] = " \
-    CONFIG_RTL8192CU=m \
-"

layers/meta-balena-raspberrypi/recipes-kernel/linux/linux-raspberrypi_6.12.bbappend

@@ -1,4 +1,4 @@
-FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:${THISDIR}/${MACHINE}:"
+FILESEXTRAPATHS:prepend := "${THISDIR}/${PN}:${THISDIR}/${MACHINE}:${THISDIR}/files:"
 
 SRC_URI:append:raspberrypi4-superhub = " \
 	file://0001-Add-gpio-wdt-DT-overlay-for-Phoenix-Board.patch \
@@ -23,146 +23,6 @@ SRC_URI:append = " \
 	file://0001-overlays-Add-overlay-for-RPI-PLC-SC16IS752.patch \
 "
 
-BALENA_CONFIGS:append = " fbtft"
-BALENA_CONFIGS[fbtft] = " \
-    CONFIG_STAGING=y \
-    CONFIG_FB_TFT=m \
-    CONFIG_FB_TFT_AGM1264K_FL=m \
-    CONFIG_FB_TFT_BD663474=m \
-    CONFIG_FB_TFT_HX8340BN=m \
-    CONFIG_FB_TFT_HX8347D=m \
-    CONFIG_FB_TFT_HX8353D=m \
-    CONFIG_FB_TFT_ILI9163=m \
-    CONFIG_FB_TFT_ILI9320=m \
-    CONFIG_FB_TFT_ILI9325=m \
-    CONFIG_FB_TFT_ILI9340=m \
-    CONFIG_FB_TFT_ILI9341=m \
-    CONFIG_FB_TFT_ILI9481=m \
-    CONFIG_FB_TFT_ILI9486=m \
-    CONFIG_FB_TFT_PCD8544=m \
-    CONFIG_FB_TFT_RA8875=m \
-    CONFIG_FB_TFT_S6D02A1=m \
-    CONFIG_FB_TFT_S6D1121=m \
-    CONFIG_FB_TFT_SSD1289=m \
-    CONFIG_FB_TFT_SSD1306=m \
-    CONFIG_FB_TFT_SSD1331=m \
-    CONFIG_FB_TFT_SSD1351=m \
-    CONFIG_FB_TFT_ST7735R=m \
-    CONFIG_FB_TFT_TINYLCD=m \
-    CONFIG_FB_TFT_TLS8204=m \
-    CONFIG_FB_TFT_UC1701=m \
-    CONFIG_FB_TFT_UPD161704=m \
-    "
-
-
-BALENA_CONFIGS:append = " ${@configure_from_version("5.17", "", " fb_tft_watterott", d)}"
-BALENA_CONFIGS[fb_tft_watterott] = "CONFIG_FB_TFT_WATTEROTT=m"
-
-BALENA_CONFIGS:append = " pca955_gpio_expander"
-BALENA_CONFIGS[pca955_gpio_expander] = " \
-    CONFIG_GPIO_PCA953X=y \
-    CONFIG_GPIO_PCA953X_IRQ=y \
-    "
-
-# requested by customer (support for Kontron PLD devices)
-BALENA_CONFIGS:append = " gpio_i2c_kempld"
-BALENA_CONFIGS_DEPS[gpio_i2c_kempld] = " \
-    CONFIG_GPIOLIB=y \
-    CONFIG_I2C=y \
-    CONFIG_HAS_IOMEM=y \
-    CONFIG_MFD_KEMPLD=m \
-"
-BALENA_CONFIGS[gpio_i2c_kempld] = " \
-    CONFIG_GPIO_KEMPLD=m \
-    CONFIG_I2C_KEMPLD=m \
-"
-
-# make sure watchdog gets enabled no matter of the BSP changes
-BALENA_CONFIGS:append = " rpi_watchdog"
-BALENA_CONFIGS_DEPS[rpi_watchdog] = " \
-    CONFIG_WATCHDOG=y \
-"
-BALENA_CONFIGS[rpi_watchdog] = " \
-    CONFIG_BCM2835_WDT=y \
-"
-
-BALENA_CONFIGS:append = " kvaser_usb_can_driver"
-
-BALENA_CONFIGS[kvaser_usb_can_driver] = " \
-    CONFIG_CAN_KVASER_USB=m \
-"
-
-BALENA_CONFIGS:append = " mcp251x_can_driver"
-
-BALENA_CONFIGS[mcp251x_can_driver] = " \
-    CONFIG_CAN_MCP251X=m \
-"
-
-BALENA_CONFIGS_DEPS[mcp251x_can_driver] = " \
-    CONFIG_SPI=y \
-    CONFIG_HAS_DMA=y \
-"
-
-BALENA_CONFIGS:append = " can_calc_bittiming"
-
-BALENA_CONFIGS[can_calc_bittiming] = " \
-		CONFIG_CAN_CALC_BITTIMING=y \
-"
-
-BALENA_CONFIGS_DEPS[can_calc_bittiming] = " \
-		CONFIG_CAN_DEV=y \
-"
-
-BALENA_CONFIGS:append = " ds1307_rtc_driver"
-
-BALENA_CONFIGS[ds1307_rtc_driver] = " \
-    CONFIG_RTC_DRV_DS1307=m \
-"
-
-BALENA_CONFIGS_DEPS[ds1307_rtc_driver] = " \
-    CONFIG_I2C=y \
-"
-
-BALENA_CONFIGS:append = " sc16is7xx_serial_driver"
-
-BALENA_CONFIGS[sc16is7xx_serial_driver] = " \
-    CONFIG_SERIAL_SC16IS7XX=m \
-"
-
-BALENA_CONFIGS_DEPS[sc16is7xx_serial_driver] = " \
-    CONFIG_I2C=y \
-"
-
-BALENA_CONFIGS:append = " mcp3422_adc_driver"
-
-BALENA_CONFIGS[mcp3422_adc_driver] = " \
-    CONFIG_MCP3422=m \
-"
-
-BALENA_CONFIGS_DEPS[mcp3422_adc_driver] = " \
-    CONFIG_I2C=y \
-"
-
-BALENA_CONFIGS:append = " sd8787_pwrseq_driver"
-
-BALENA_CONFIGS[sd8787_pwrseq_driver] = " \
-    CONFIG_PWRSEQ_SD8787=m \
-"
-
-BALENA_CONFIGS_DEPS[sd8787_pwrseq_driver] = " \
-    CONFIG_OF=y \
-"
-
-BALENA_CONFIGS:append = " serial_8250"
-BALENA_CONFIGS[serial_8250] = " \
-    CONFIG_SERIAL_8250=y \
-    CONFIG_SERIAL_8250_CONSOLE=y \
-    CONFIG_SERIAL_8250_NR_UARTS=1 \
-    CONFIG_SERIAL_8250_EXTENDED=y \
-    CONFIG_SERIAL_8250_SHARE_IRQ=y \
-    CONFIG_SERIAL_8250_BCM2835AUX=y \
-"
-
 # The Pi3-64 and Pi4-64 are the only boards very low on rootfs space for now
 # so we add this as per https://github.com/balena-os/meta-balena/pull/2411
 BALENA_CONFIGS:append:raspberrypi4-64 = " optimize-size"
@@ -171,11 +31,6 @@ BALENA_CONFIGS[optimize-size] = " \
     CONFIG_CC_OPTIMIZE_FOR_SIZE=y \
 "
 
-BALENA_CONFIGS:append = " iio_pressure_drivers"
-BALENA_CONFIGS[iio_pressure_drivers] = " \
-    CONFIG_BMP280=m \
-"
-
 # Fix dtbo loading on 64bits,
 # see commit 949b88bb for details
 get_cc_option () {