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Subject[PATCH v2 2/3] mfd: lpc_ich: Add support for SPI serial flash host controller
Date
Many Intel CPUs including Haswell, Broadwell and Baytrail have SPI serial
flash host controller as part of the LPC device. This will populate an MFD
cell suitable for the SPI host controller driver if we know that the LPC
device has one.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
drivers/mfd/lpc_ich.c | 92 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/lpc_ich.h | 3 ++
2 files changed, 95 insertions(+)

diff --git a/drivers/mfd/lpc_ich.c b/drivers/mfd/lpc_ich.c
index bd3aa4578346..56a0e98a5f89 100644
--- a/drivers/mfd/lpc_ich.c
+++ b/drivers/mfd/lpc_ich.c
@@ -83,6 +83,15 @@
#define ACPIBASE_GCS_OFF 0x3410
#define ACPIBASE_GCS_END 0x3414

+#define SPIBASE_BYT 0x54
+#define SPIBASE_BYT_SZ 512
+#define SPIBASE_BYT_EN BIT(1)
+
+#define SPIBASE_LPT 0x3800
+#define SPIBASE_LPT_SZ 512
+#define BCR 0xdc
+#define BCR_WPD BIT(0)
+
#define GPIOBASE_ICH0 0x58
#define GPIOCTRL_ICH0 0x5C
#define GPIOBASE_ICH6 0x48
@@ -133,6 +142,12 @@ static struct resource gpio_ich_res[] = {
},
};

+static struct resource intel_spi_res[] = {
+ {
+ .flags = IORESOURCE_MEM,
+ }
+};
+
static struct mfd_cell lpc_ich_wdt_cell = {
.name = "iTCO_wdt",
.num_resources = ARRAY_SIZE(wdt_ich_res),
@@ -147,6 +162,14 @@ static struct mfd_cell lpc_ich_gpio_cell = {
.ignore_resource_conflicts = true,
};

+
+static struct mfd_cell lpc_ich_spi_cell = {
+ .name = "intel-spi",
+ .num_resources = ARRAY_SIZE(intel_spi_res),
+ .resources = intel_spi_res,
+ .ignore_resource_conflicts = true,
+};
+
/* chipset related info */
enum lpc_chipsets {
LPC_ICH = 0, /* ICH */
@@ -493,10 +516,12 @@ static struct lpc_ich_info lpc_chipset_info[] = {
[LPC_LPT] = {
.name = "Lynx Point",
.iTCO_version = 2,
+ .spi_type = INTEL_SPI_LPT,
},
[LPC_LPT_LP] = {
.name = "Lynx Point_LP",
.iTCO_version = 2,
+ .spi_type = INTEL_SPI_LPT,
},
[LPC_WBG] = {
.name = "Wellsburg",
@@ -510,6 +535,7 @@ static struct lpc_ich_info lpc_chipset_info[] = {
[LPC_BAYTRAIL] = {
.name = "Bay Trail SoC",
.iTCO_version = 3,
+ .spi_type = INTEL_SPI_BYT,
},
[LPC_COLETO] = {
.name = "Coleto Creek",
@@ -518,10 +544,12 @@ static struct lpc_ich_info lpc_chipset_info[] = {
[LPC_WPT_LP] = {
.name = "Wildcat Point_LP",
.iTCO_version = 2,
+ .spi_type = INTEL_SPI_LPT,
},
[LPC_BRASWELL] = {
.name = "Braswell SoC",
.iTCO_version = 3,
+ .spi_type = INTEL_SPI_BYT,
},
[LPC_LEWISBURG] = {
.name = "Lewisburg",
@@ -1050,6 +1078,64 @@ wdt_done:
return ret;
}

+static int lpc_ich_init_spi(struct pci_dev *dev)
+{
+ struct lpc_ich_priv *priv = pci_get_drvdata(dev);
+ struct resource *res = &intel_spi_res[0];
+ struct intel_spi_boardinfo *info;
+ u32 spi_base, rcba, bcr;
+
+ info = devm_kzalloc(&dev->dev, sizeof(*info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ info->type = lpc_chipset_info[priv->chipset].spi_type;
+
+ switch (info->type) {
+ case INTEL_SPI_BYT:
+ pci_read_config_dword(dev, SPIBASE_BYT, &spi_base);
+ if (spi_base & SPIBASE_BYT_EN) {
+ res->start = spi_base & ~(SPIBASE_BYT_SZ - 1);
+ res->end = res->start + SPIBASE_BYT_SZ - 1;
+ }
+ break;
+
+ case INTEL_SPI_LPT:
+ pci_read_config_dword(dev, RCBABASE, &rcba);
+ if (rcba & 1) {
+ spi_base = rcba & ~(SPIBASE_LPT_SZ - 1);
+ res->start = spi_base + SPIBASE_LPT;
+ res->end = res->start + SPIBASE_LPT_SZ - 1;
+
+ /*
+ * Try to make the flash chip writeable now by
+ * setting BCR_WPD. It it fails we tell the driver
+ * that it can only read the chip.
+ */
+ pci_read_config_dword(dev, BCR, &bcr);
+ if (!(bcr & BCR_WPD)) {
+ bcr |= BCR_WPD;
+ pci_write_config_dword(dev, BCR, bcr);
+ pci_read_config_dword(dev, BCR, &bcr);
+ }
+ info->writeable = !!(bcr & BCR_WPD);
+ }
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (!res->start)
+ return -ENODEV;
+
+ lpc_ich_spi_cell.platform_data = info;
+ lpc_ich_spi_cell.pdata_size = sizeof(*info);
+
+ return mfd_add_devices(&dev->dev, PLATFORM_DEVID_NONE,
+ &lpc_ich_spi_cell, 1, NULL, 0, NULL);
+}
+
static int lpc_ich_probe(struct pci_dev *dev,
const struct pci_device_id *id)
{
@@ -1093,6 +1179,12 @@ static int lpc_ich_probe(struct pci_dev *dev,
cell_added = true;
}

+ if (lpc_chipset_info[priv->chipset].spi_type) {
+ ret = lpc_ich_init_spi(dev);
+ if (!ret)
+ cell_added = true;
+ }
+
/*
* We only care if at least one or none of the cells registered
* successfully.
diff --git a/include/linux/mfd/lpc_ich.h b/include/linux/mfd/lpc_ich.h
index 2b300b44f994..fba8fcb54f8c 100644
--- a/include/linux/mfd/lpc_ich.h
+++ b/include/linux/mfd/lpc_ich.h
@@ -20,6 +20,8 @@
#ifndef LPC_ICH_H
#define LPC_ICH_H

+#include <linux/platform_data/intel-spi.h>
+
/* GPIO resources */
#define ICH_RES_GPIO 0
#define ICH_RES_GPE0 1
@@ -40,6 +42,7 @@ struct lpc_ich_info {
char name[32];
unsigned int iTCO_version;
unsigned int gpio_version;
+ enum intel_spi_type spi_type;
u8 use_gpio;
};

--
2.8.1
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