flashrom: add lspcon-i2c-spi programmer support

Created lspcon-i2c-spi flashrom device that uses udev to detect i2c
devices that can be updated with the lspcon-i2c-spi flashrom programmer.

This change implements the logic from crrev.com/c/2792124 adapted to the
upstream flashrom plugin.

plugins/flashrom/README.md

@@ -39,7 +39,7 @@ The coreboot DMI version string always starts with `CBET`.
 GUID Generation
 ---------------
 
-These device uses hardware ID values which are derived from SMBIOS.
+Internal device uses hardware ID values which are derived from SMBIOS.
 
  * HardwareID-3
  * HardwareID-4
@@ -47,9 +47,12 @@ These device uses hardware ID values which are derived from SMBIOS.
  * HardwareID-6
  * HardwareID-10
 
-These device uses hardware ID values which are derived from SMBIOS. They should
-match the values provided by `fwupdtool hwids` or the `ComputerHardwareIds.exe`
-Windows utility.
+They should match the values provided by `fwupdtool hwids` or the
+`ComputerHardwareIds.exe` Windows utility.
+
+lspcon-i2c-spi devices use the customized DeviceInstanceId values, e.g.
+
+ * FLASHROM-LSPCON-I2C-SPI\VEN_1AF8&DEV_0175
 
 Update Behavior
 ---------------

plugins/flashrom/flashrom.quirk

@@ -32,3 +32,14 @@ VersionFormat=number
 [0ee5867c-93f0-5fb4-adf1-9d686ea1183a]
 Branch=coreboot
 VersionFormat=number
+
+# match all devices with this udev subsystem
+[I2C]
+Plugin = flashrom
+
+# Parade PS175
+[1AF80175:00]
+Plugin=flashrom
+FlashromProgrammer=lspcon_i2c_spi
+Name=PS175
+Vendor=Parade

plugins/flashrom/fu-flashrom-lspcon-i2c-spi-device.c

@@ -0,0 +1,126 @@
+/*
+ * Copyright (C) 2021 Daniel Campello <campello@chromium.org>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ */
+
+#include "config.h"
+
+#include "fu-flashrom-device.h"
+#include "fu-flashrom-lspcon-i2c-spi-device.h"
+
+#include <libflashrom.h>
+
+#define I2C_PATH_REGEX "/i2c-([0-9]+)/"
+#define HID_LENGTH 8
+#define DEVICE_GUID_FORMAT "FLASHROM-LSPCON-I2C-SPI\\VEN_%s&DEV_%s"
+
+struct _FuFlashromLspconI2cSpiDevice {
+	FuFlashromDevice	  parent_instance;
+	gint			  bus_number;
+};
+
+G_DEFINE_TYPE (FuFlashromLspconI2cSpiDevice, fu_flashrom_lspcon_i2c_spi_device,
+	       FU_TYPE_FLASHROM_DEVICE)
+
+static void
+fu_flashrom_lspcon_i2c_spi_device_init (FuFlashromLspconI2cSpiDevice *self)
+{
+	fu_device_add_flag (FU_DEVICE (self), FWUPD_DEVICE_FLAG_UPDATABLE);
+	fu_device_set_version_format (FU_DEVICE (self), FWUPD_VERSION_FORMAT_PAIR);
+}
+
+static gboolean
+fu_flashrom_lspcon_i2c_spi_device_probe (FuDevice *device, GError **error)
+{
+	FuFlashromLspconI2cSpiDevice *self = FU_FLASHROM_LSPCON_I2C_SPI_DEVICE (device);
+	FuFlashromDevice *flashrom_device = FU_FLASHROM_DEVICE (device);
+	FuDeviceClass *klass =
+		FU_DEVICE_CLASS (fu_flashrom_lspcon_i2c_spi_device_parent_class);
+	g_autoptr(GRegex) regex = NULL;
+	g_autoptr(GMatchInfo) info = NULL;
+	const gchar *path = NULL;
+
+	/* FuFlashromDevice->probe */
+	if (!klass->probe (device, error))
+		return FALSE;
+
+	if (g_strcmp0 (fu_flashrom_device_get_programmer_name (flashrom_device),
+		       "lspcon_i2c_spi") != 0) {
+		g_set_error_literal (error,
+				     FWUPD_ERROR,
+				     FWUPD_ERROR_NOT_SUPPORTED,
+				     "invalid programmer");
+		return FALSE;
+	}
+
+	/* get bus number out of sysfs path */
+	path = fu_udev_device_get_sysfs_path (FU_UDEV_DEVICE (device));
+	regex = g_regex_new (I2C_PATH_REGEX, 0, 0, error);
+	if (regex && g_regex_match_full (regex, path, -1, 0, 0, &info, error)) {
+		self->bus_number = g_ascii_strtoll ( g_match_info_fetch (info, 1),
+					       NULL, 10);
+		return TRUE;
+	}
+	return FALSE;
+}
+
+static gboolean
+fu_flashrom_lspcon_i2c_spi_device_open (FuDevice *device,
+					GError **error)
+{
+	FuFlashromLspconI2cSpiDevice *self = FU_FLASHROM_LSPCON_I2C_SPI_DEVICE (device);
+	FuFlashromDevice *flashrom_device = FU_FLASHROM_DEVICE (device);
+	FuDeviceClass *klass =
+		FU_DEVICE_CLASS (fu_flashrom_lspcon_i2c_spi_device_parent_class);
+	g_autofree gchar *temp = NULL;
+
+	/* flashrom_programmer_init() mutates the programmer_args string. */
+	temp = g_strdup_printf ("bus=%d", self->bus_number);
+	fu_flashrom_device_set_programmer_args (flashrom_device, temp);
+
+	return klass->open (device, error);
+}
+
+static gboolean
+fu_flashrom_lspcon_i2c_spi_device_setup (FuDevice *device, GError **error)
+{
+	const gchar *hw_id = NULL;
+	g_autofree gchar *vid = NULL;
+	g_autofree gchar *pid = NULL;
+	g_autofree gchar *vendor_id = NULL;
+	g_autofree gchar *temp = NULL;
+	g_autofree gchar *guid = NULL;
+
+	hw_id = fu_udev_device_get_sysfs_attr (FU_UDEV_DEVICE (device), "name", error);
+	if (hw_id == NULL) {
+		g_set_error_literal (error,
+				     FWUPD_ERROR,
+				     FWUPD_ERROR_NOT_SUPPORTED,
+				     "HID not found");
+		return FALSE;
+	}
+	vid = g_strndup (hw_id, HID_LENGTH / 2);
+	pid = g_strndup (&hw_id[HID_LENGTH / 2], HID_LENGTH / 2);
+	vendor_id = g_strdup_printf ("I2C:%s", vid);
+	fu_device_add_vendor_id (device, vendor_id);
+
+	temp = g_strdup_printf (DEVICE_GUID_FORMAT, vid, pid);
+	fu_device_add_instance_id (device, temp);
+	guid = fwupd_guid_hash_string (temp);
+	fu_device_add_guid (device, guid);
+
+	/* TODO: Get the real version number. */
+	fu_device_set_version (device, "0.0");
+
+	return TRUE;
+}
+
+static void
+fu_flashrom_lspcon_i2c_spi_device_class_init (FuFlashromLspconI2cSpiDeviceClass *klass)
+{
+	FuDeviceClass *klass_device = FU_DEVICE_CLASS (klass);
+	klass_device->probe = fu_flashrom_lspcon_i2c_spi_device_probe;
+	klass_device->open = fu_flashrom_lspcon_i2c_spi_device_open;
+	klass_device->setup = fu_flashrom_lspcon_i2c_spi_device_setup;
+}

plugins/flashrom/fu-flashrom-lspcon-i2c-spi-device.h

@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) 2021 Daniel Campello <campello@chromium.org>
+ *
+ * SPDX-License-Identifier: LGPL-2.1+
+ */
+
+#pragma once
+
+#include "fu-flashrom-device.h"
+
+#define FU_TYPE_FLASHROM_LSPCON_I2C_SPI_DEVICE \
+	(fu_flashrom_lspcon_i2c_spi_device_get_type ())
+G_DECLARE_FINAL_TYPE (FuFlashromLspconI2cSpiDevice,
+		      fu_flashrom_lspcon_i2c_spi_device, FU,
+		      FLASHROM_LSPCON_I2C_SPI_DEVICE, FuFlashromDevice)

plugins/flashrom/fu-plugin-flashrom.c

@@ -26,6 +26,7 @@
 
 #include "fu-plugin-vfuncs.h"
 #include "fu-flashrom-internal-device.h"
+#include "fu-flashrom-lspcon-i2c-spi-device.h"
 
 #include <libflashrom.h>
 
@@ -40,6 +41,8 @@ fu_plugin_init (FuPlugin *plugin)
 	fu_plugin_add_rule (plugin, FU_PLUGIN_RULE_METADATA_SOURCE, "linux_lockdown");
 	fu_plugin_add_rule (plugin, FU_PLUGIN_RULE_CONFLICTS, "coreboot"); /* obsoleted */
 	fu_plugin_add_flag (plugin, FWUPD_PLUGIN_FLAG_REQUIRE_HWID);
+	fu_plugin_set_device_gtype (plugin, FU_TYPE_FLASHROM_LSPCON_I2C_SPI_DEVICE);
+	fu_context_add_udev_subsystem (ctx, "i2c");
 	fu_context_add_quirk_key (ctx, "FlashromProgrammer");
 }
 

plugins/flashrom/meson.build

@@ -10,6 +10,7 @@ shared_module('fu_plugin_flashrom',
   sources : [
     'fu-flashrom-device.c',
     'fu-flashrom-internal-device.c',
+    'fu-flashrom-lspcon-i2c-spi-device.c',
     'fu-plugin-flashrom.c',
   ],
   include_directories : [