x86/platform/intel-mid: Enable SD card detection on Merrifield

Intel Merrifield platform provides SD card interface. The interface allows user
to plug SD card to extend storage capacity.

Append the essential data to enable SD card detection on it.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160831135713.79066-2-andriy.shevchenko@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/platform/intel-mid/device_libs/Makefile

 # Family-Level Interface Shim (FLIS)
 obj-$(subst m,y,$(CONFIG_PINCTRL_MERRIFIELD)) += platform_mrfld_pinctrl.o
+# SDHCI Devices
+obj-$(subst m,y,$(CONFIG_MMC_SDHCI_PCI)) += platform_mrfld_sd.o
 # WiFi
 obj-$(subst m,y,$(CONFIG_BRCMFMAC_SDIO)) += platform_bcm43xx.o
 # IPC Devices

arch/x86/platform/intel-mid/device_libs/platform_mrfld_sd.c

+/*
+ * SDHCI platform data initilisation file
+ *
+ * (C) Copyright 2016 Intel Corporation
+ * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#include <linux/init.h>
+#include <linux/pci.h>
+
+#include <linux/mmc/sdhci-pci-data.h>
+
+#include <asm/intel-mid.h>
+
+#define INTEL_MRFLD_SD			2
+#define INTEL_MRFLD_SD_CD_GPIO		77
+
+static struct sdhci_pci_data mrfld_sdhci_pci_data = {
+	.rst_n_gpio	= -EINVAL,
+	.cd_gpio	= INTEL_MRFLD_SD_CD_GPIO,
+};
+
+static struct sdhci_pci_data *
+mrfld_sdhci_pci_get_data(struct pci_dev *pdev, int slotno)
+{
+	unsigned int func = PCI_FUNC(pdev->devfn);
+
+	if (func == INTEL_MRFLD_SD)
+		return &mrfld_sdhci_pci_data;
+
+	return NULL;
+}
+
+static int __init mrfld_sd_init(void)
+{
+	if (intel_mid_identify_cpu() != INTEL_MID_CPU_CHIP_TANGIER)
+		return -ENODEV;
+
+	sdhci_pci_get_data = mrfld_sdhci_pci_get_data;
+	return 0;
+}
+arch_initcall(mrfld_sd_init);