x86, mrst: add platform support for MSIC MFD driver

The MSIC MFD driver creates platform devices for MSIC device drivers so we
don't need to create them in platform code anymore.

This patch adds a new runtime check which determines whether we are running
on a Medfield platform and enables the MSIC MFD driver accordingly.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

arch/x86/platform/mrst/mrst.c

@@ -25,6 +25,7 @@
 #include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/notifier.h>
+#include <linux/mfd/intel_msic.h>
 
 #include <asm/setup.h>
 #include <asm/mpspec_def.h>
@@ -481,6 +482,128 @@ static void __init *no_platform_data(void *info)
 	return NULL;
 }
 
+static struct resource msic_resources[] = {
+	{
+		.start	= INTEL_MSIC_IRQ_PHYS_BASE,
+		.end	= INTEL_MSIC_IRQ_PHYS_BASE + 64 - 1,
+		.flags	= IORESOURCE_MEM,
+	},
+};
+
+static struct intel_msic_platform_data msic_pdata;
+
+static struct platform_device msic_device = {
+	.name		= "intel_msic",
+	.id		= -1,
+	.dev		= {
+		.platform_data	= &msic_pdata,
+	},
+	.num_resources	= ARRAY_SIZE(msic_resources),
+	.resource	= msic_resources,
+};
+
+static inline bool mrst_has_msic(void)
+{
+	return mrst_identify_cpu() == MRST_CPU_CHIP_PENWELL;
+}
+
+static int msic_scu_status_change(struct notifier_block *nb,
+				  unsigned long code, void *data)
+{
+	if (code == SCU_DOWN) {
+		platform_device_unregister(&msic_device);
+		return 0;
+	}
+
+	return platform_device_register(&msic_device);
+}
+
+static int __init msic_init(void)
+{
+	static struct notifier_block msic_scu_notifier = {
+		.notifier_call	= msic_scu_status_change,
+	};
+
+	/*
+	 * We need to be sure that the SCU IPC is ready before MSIC device
+	 * can be registered.
+	 */
+	if (mrst_has_msic())
+		intel_scu_notifier_add(&msic_scu_notifier);
+
+	return 0;
+}
+arch_initcall(msic_init);
+
+/*
+ * msic_generic_platform_data - sets generic platform data for the block
+ * @info: pointer to the SFI device table entry for this block
+ * @block: MSIC block
+ *
+ * Function sets IRQ number from the SFI table entry for given device to
+ * the MSIC platform data.
+ */
+static void *msic_generic_platform_data(void *info, enum intel_msic_block block)
+{
+	struct sfi_device_table_entry *entry = info;
+
+	BUG_ON(block < 0 || block >= INTEL_MSIC_BLOCK_LAST);
+	msic_pdata.irq[block] = entry->irq;
+
+	return no_platform_data(info);
+}
+
+static void *msic_battery_platform_data(void *info)
+{
+	return msic_generic_platform_data(info, INTEL_MSIC_BLOCK_BATTERY);
+}
+
+static void *msic_gpio_platform_data(void *info)
+{
+	static struct intel_msic_gpio_pdata pdata;
+	int gpio = get_gpio_by_name("msic_gpio_base");
+
+	if (gpio < 0)
+		return NULL;
+
+	pdata.gpio_base = gpio;
+	msic_pdata.gpio = &pdata;
+
+	return msic_generic_platform_data(info, INTEL_MSIC_BLOCK_GPIO);
+}
+
+static void *msic_audio_platform_data(void *info)
+{
+	struct platform_device *pdev;
+
+	pdev = platform_device_register_simple("sst-platform", -1, NULL, 0);
+	if (IS_ERR(pdev)) {
+		pr_err("failed to create audio platform device\n");
+		return NULL;
+	}
+
+	return msic_generic_platform_data(info, INTEL_MSIC_BLOCK_AUDIO);
+}
+
+static void *msic_power_btn_platform_data(void *info)
+{
+	return msic_generic_platform_data(info, INTEL_MSIC_BLOCK_POWER_BTN);
+}
+
+static void *msic_ocd_platform_data(void *info)
+{
+	static struct intel_msic_ocd_pdata pdata;
+	int gpio = get_gpio_by_name("ocd_gpio");
+
+	if (gpio < 0)
+		return NULL;
+
+	pdata.gpio = gpio;
+	msic_pdata.ocd = &pdata;
+
+	return msic_generic_platform_data(info, INTEL_MSIC_BLOCK_OCD);
+}
+
 static const struct devs_id __initconst device_ids[] = {
 	{"pmic_gpio", SFI_DEV_TYPE_SPI, 1, &pmic_gpio_platform_data},
 	{"spi_max3111", SFI_DEV_TYPE_SPI, 0, &max3111_platform_data},
@@ -489,7 +612,14 @@ static const struct devs_id __initconst device_ids[] = {
 	{"emc1403", SFI_DEV_TYPE_I2C, 1, &emc1403_platform_data},
 	{"i2c_accel", SFI_DEV_TYPE_I2C, 0, &lis331dl_platform_data},
 	{"pmic_audio", SFI_DEV_TYPE_IPC, 1, &no_platform_data},
-	{"msic_audio", SFI_DEV_TYPE_IPC, 1, &no_platform_data},
+
+	/* MSIC subdevices */
+	{"msic_battery", SFI_DEV_TYPE_IPC, 1, &msic_battery_platform_data},
+	{"msic_gpio", SFI_DEV_TYPE_IPC, 1, &msic_gpio_platform_data},
+	{"msic_audio", SFI_DEV_TYPE_IPC, 1, &msic_audio_platform_data},
+	{"msic_power_btn", SFI_DEV_TYPE_IPC, 1, &msic_power_btn_platform_data},
+	{"msic_ocd", SFI_DEV_TYPE_IPC, 1, &msic_ocd_platform_data},
+
 	{},
 };
 
@@ -610,19 +740,37 @@ static void __init install_irq_resource(struct platform_device *pdev, int irq)
 	platform_device_add_resources(pdev, &res, 1);
 }
 
-static void __init sfi_handle_ipc_dev(struct platform_device *pdev)
+static void __init sfi_handle_ipc_dev(struct sfi_device_table_entry *entry)
 {
 	const struct devs_id *dev = device_ids;
+	struct platform_device *pdev;
 	void *pdata = NULL;
 
 	while (dev->name[0]) {
 		if (dev->type == SFI_DEV_TYPE_IPC &&
-			!strncmp(dev->name, pdev->name, SFI_NAME_LEN)) {
-			pdata = dev->get_platform_data(pdev);
+			!strncmp(dev->name, entry->name, SFI_NAME_LEN)) {
+			pdata = dev->get_platform_data(entry);
 			break;
 		}
 		dev++;
 	}
+
+	/*
+	 * On Medfield the platform device creation is handled by the MSIC
+	 * MFD driver so we don't need to do it here.
+	 */
+	if (mrst_has_msic())
+		return;
+
+	/* ID as IRQ is a hack that will go away */
+	pdev = platform_device_alloc(entry->name, entry->irq);
+	if (pdev == NULL) {
+		pr_err("out of memory for SFI platform device '%s'.\n",
+			entry->name);
+		return;
+	}
+	install_irq_resource(pdev, entry->irq);
+
 	pdev->dev.platform_data = pdata;
 	intel_scu_device_register(pdev);
 }
@@ -675,7 +823,6 @@ static int __init sfi_parse_devs(struct sfi_table_header *table)
 	struct sfi_device_table_entry *pentry;
 	struct spi_board_info spi_info;
 	struct i2c_board_info i2c_info;
-	struct platform_device *pdev;
 	int num, i, bus;
 	int ioapic;
 	struct io_apic_irq_attr irq_attr;
@@ -703,17 +850,9 @@ static int __init sfi_parse_devs(struct sfi_table_header *table)
 
 		switch (pentry->type) {
 		case SFI_DEV_TYPE_IPC:
-			/* ID as IRQ is a hack that will go away */
-			pdev = platform_device_alloc(pentry->name, irq);
-			if (pdev == NULL) {
-				pr_err("out of memory for SFI platform device '%s'.\n",
-							pentry->name);
-				continue;
-			}
-			install_irq_resource(pdev, irq);
 			pr_debug("info[%2d]: IPC bus, name = %16.16s, "
-				"irq = 0x%2x\n", i, pentry->name, irq);
-			sfi_handle_ipc_dev(pdev);
+				"irq = 0x%2x\n", i, pentry->name, pentry->irq);
+			sfi_handle_ipc_dev(pentry);
 			break;
 		case SFI_DEV_TYPE_SPI:
 			memset(&spi_info, 0, sizeof(spi_info));