linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH 0/3] spi-nor: Add support for Intel SPI serial flash controller
@ 2016-06-14 11:43 Mika Westerberg
  2016-06-14 11:43 ` [PATCH 1/3] " Mika Westerberg
                   ` (2 more replies)
  0 siblings, 3 replies; 6+ messages in thread
From: Mika Westerberg @ 2016-06-14 11:43 UTC (permalink / raw)
  To: linux-mtd
  Cc: Brian Norris, David Woodhouse, Lee Jones, Peter Tyser,
	key.seong.lim, Mika Westerberg, linux-kernel

Hi,

This series adds support for the Intel SPI serial flash controller found on
many recent Intel CPUs including Baytrail and Braswell. This driver makes
it possible to access the BIOS and other platform data which is stored on
the SPI serial flash. It is also possible to upgrade the BIOS using this
driver if it has not been protected by special hardware bits.

The patch [1/3] includes documentation how to upgrade BIOS on MinnowBoard
MAX.

Since poking the SPI serial flash can brick the machine, this driver can
only be enabled when CONFIG_EXPERT=y and even then it will remain read-only
unless instructed othwerwise by module parameter.

Mika Westerberg (3):
  spi-nor: Add support for Intel SPI serial flash controller
  mfd: lpc_ich: Add support for SPI serial flash host controller
  mfd: lpc_ich: Add support for Intel Apollo Lake SoC

 Documentation/mtd/intel-spi.txt          |  87 ++++
 drivers/mfd/lpc_ich.c                    | 134 ++++++
 drivers/mtd/spi-nor/Kconfig              |  20 +
 drivers/mtd/spi-nor/Makefile             |   2 +
 drivers/mtd/spi-nor/intel-spi-platform.c |  57 +++
 drivers/mtd/spi-nor/intel-spi.c          | 748 +++++++++++++++++++++++++++++++
 drivers/mtd/spi-nor/intel-spi.h          |  24 +
 include/linux/mfd/lpc_ich.h              |   3 +
 include/linux/platform_data/intel-spi.h  |  31 ++
 9 files changed, 1106 insertions(+)
 create mode 100644 Documentation/mtd/intel-spi.txt
 create mode 100644 drivers/mtd/spi-nor/intel-spi-platform.c
 create mode 100644 drivers/mtd/spi-nor/intel-spi.c
 create mode 100644 drivers/mtd/spi-nor/intel-spi.h
 create mode 100644 include/linux/platform_data/intel-spi.h

-- 
2.8.1

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 1/3] spi-nor: Add support for Intel SPI serial flash controller
  2016-06-14 11:43 [PATCH 0/3] spi-nor: Add support for Intel SPI serial flash controller Mika Westerberg
@ 2016-06-14 11:43 ` Mika Westerberg
  2016-06-14 11:43 ` [PATCH 2/3] mfd: lpc_ich: Add support for SPI serial flash host controller Mika Westerberg
  2016-06-14 11:43 ` [PATCH 3/3] mfd: lpc_ich: Add support for Intel Apollo Lake SoC Mika Westerberg
  2 siblings, 0 replies; 6+ messages in thread
From: Mika Westerberg @ 2016-06-14 11:43 UTC (permalink / raw)
  To: linux-mtd
  Cc: Brian Norris, David Woodhouse, Lee Jones, Peter Tyser,
	key.seong.lim, Mika Westerberg, linux-kernel

Add support for the SPI serial flash host controller found on many Intel
CPUs including Baytrail and Braswell. The SPI serial flash controller is
used to access BIOS and other platform specific information. By default the
driver exposes a single read-only MTD device but with a module parameter
'intel-spi.writeable=1' the MTD device can be made read-write which makes
it possible to upgrade BIOS directly from Linux.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 Documentation/mtd/intel-spi.txt          |  87 ++++
 drivers/mtd/spi-nor/Kconfig              |  20 +
 drivers/mtd/spi-nor/Makefile             |   2 +
 drivers/mtd/spi-nor/intel-spi-platform.c |  57 +++
 drivers/mtd/spi-nor/intel-spi.c          | 748 +++++++++++++++++++++++++++++++
 drivers/mtd/spi-nor/intel-spi.h          |  24 +
 include/linux/platform_data/intel-spi.h  |  31 ++
 7 files changed, 969 insertions(+)
 create mode 100644 Documentation/mtd/intel-spi.txt
 create mode 100644 drivers/mtd/spi-nor/intel-spi-platform.c
 create mode 100644 drivers/mtd/spi-nor/intel-spi.c
 create mode 100644 drivers/mtd/spi-nor/intel-spi.h
 create mode 100644 include/linux/platform_data/intel-spi.h

diff --git a/Documentation/mtd/intel-spi.txt b/Documentation/mtd/intel-spi.txt
new file mode 100644
index 000000000000..2d30525c79a7
--- /dev/null
+++ b/Documentation/mtd/intel-spi.txt
@@ -0,0 +1,87 @@
+Upgrading BIOS using intel-spi
+------------------------------
+
+Many Intel CPUs like Baytrail and Braswell include SPI serial flash host
+controller which is used to hold BIOS and other platform specific data.
+Since contents of the SPI serial flash is crucial for machine to function,
+it is typically protected by different hardware protection mechanisms to
+avoid accidental (or on purpose) overwrite of the content.
+
+Not all manufacturers protect the SPI serial flash, mainly because it
+allows upgrading the BIOS image directly from an OS.
+
+The intel-spi driver makes it possible to read and write the SPI serial
+flash, if certain protection bits are not set and locked. If it finds
+any of them set, the whole MTD device is made read-only to prevent
+partial overwrites. By default the driver exposes SPI serial flash
+contents as read-only but it can be changed from kernel command line,
+passing "intel-spi.writeable=1".
+
+Please keep in mind that overwriting the BIOS image on SPI serial flash
+might render the machine unbootable and requires special equipment like
+Dediprog to revive. You have been warned!
+
+Below are the steps how to upgrade MinnowBoard MAX BIOS directly from
+Linux.
+
+ 1) Download and extract the latest Minnowboard MAX BIOS SPI image
+    [1]. At the time writing this the latest image is v92.
+
+ 2) Install mtd-utils package [2]. We need this in order to erase the SPI
+    serial flash. Distros like Debian and Fedora have this prepackaged with
+    name "mtd-utils".
+
+ 3) Add "intel-spi.writeable=1" to the kernel command line and reboot
+    the board.
+
+ 4) Once the board is up and running again, find the right MTD partition
+    (it is named as "BIOS"):
+
+    # cat /proc/mtd
+    dev:    size   erasesize  name
+    mtd0: 00800000 00001000 "BIOS"
+
+    So here it will be /dev/mtd0 but it may vary.
+
+ 5) Make backup of the existing image first:
+
+    # dd if=/dev/mtd0ro of=bios.bak
+    16384+0 records in
+    16384+0 records out
+    8388608 bytes (8.4 MB) copied, 10.0269 s, 837 kB/s
+
+ 6) Verify the backup
+
+    # sha1sum /dev/mtd0ro bios.bak
+    fdbb011920572ca6c991377c4b418a0502668b73  /dev/mtd0ro
+    fdbb011920572ca6c991377c4b418a0502668b73  bios.bak
+
+    The SHA1 sums must match. Otherwise do not continue any further!
+
+ 7) Erase the SPI serial flash. After this step, do not reboot the
+    board! Otherwise it will not start anymore.
+
+    # flash_erase /dev/mtd0 0 0
+    Erasing 4 Kibyte @ 7ff000 -- 100 % complete
+
+ 8) Once completed without errors you can write the new BIOS image:
+
+    # dd if=MNW2MAX1.X64.0092.R01.1605221712.bin of=/dev/mtd0
+
+ 9) Verify that the new content of the SPI serial flash matches the new
+    BIOS image:
+
+    # sha1sum /dev/mtd0ro MNW2MAX1.X64.0092.R01.1605221712.bin
+    9b4df9e4be2057fceec3a5529ec3d950836c87a2  /dev/mtd0ro
+    9b4df9e4be2057fceec3a5529ec3d950836c87a2 MNW2MAX1.X64.0092.R01.1605221712.bin
+
+    The SHA1 sums should match.
+
+ 10) Now you can reboot your board and observe the new BIOS starting up
+     properly.
+
+References
+----------
+
+[1] https://firmware.intel.com/sites/default/files/MinnowBoard.MAX_.X64.92.R01.zip
+[2] http://www.linux-mtd.infradead.org/
diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index d42c98e1f581..119712b6ae3b 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig
@@ -49,4 +49,24 @@ config SPI_NXP_SPIFI
 	  Flash. Enable this option if you have a device with a SPIFI
 	  controller and want to access the Flash as a mtd device.
 
+config SPI_INTEL_SPI
+	tristate
+
+config SPI_INTEL_SPI_PLATFORM
+	tristate "Intel PCH/PCU SPI flash platform driver" if EXPERT
+	depends on X86
+	select SPI_INTEL_SPI
+	help
+	  This enables platform support for the Intel PCH/PCU SPI
+	  controller in master mode. This controller is present in modern
+	  Intel hardware and is used to hold BIOS and other persistent
+	  settings. Using this driver it is possible to upgrade BIOS
+	  directly from Linux.
+
+	  Say N here unless you know what you are doing. Overwriting the
+	  SPI flash may render the system unbootable.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called intel-spi-platform.
+
 endif # MTD_SPI_NOR
diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
index 0bf3a7f81675..60c0b1bb8264 100644
--- a/drivers/mtd/spi-nor/Makefile
+++ b/drivers/mtd/spi-nor/Makefile
@@ -2,3 +2,5 @@ obj-$(CONFIG_MTD_SPI_NOR)	+= spi-nor.o
 obj-$(CONFIG_SPI_FSL_QUADSPI)	+= fsl-quadspi.o
 obj-$(CONFIG_MTD_MT81xx_NOR)    += mtk-quadspi.o
 obj-$(CONFIG_SPI_NXP_SPIFI)	+= nxp-spifi.o
+obj-$(CONFIG_SPI_INTEL_SPI)	+= intel-spi.o
+obj-$(CONFIG_SPI_INTEL_SPI_PLATFORM)	+= intel-spi-platform.o
diff --git a/drivers/mtd/spi-nor/intel-spi-platform.c b/drivers/mtd/spi-nor/intel-spi-platform.c
new file mode 100644
index 000000000000..5c943df9398f
--- /dev/null
+++ b/drivers/mtd/spi-nor/intel-spi-platform.c
@@ -0,0 +1,57 @@
+/*
+ * Intel PCH/PCU SPI flash platform driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@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 version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "intel-spi.h"
+
+static int intel_spi_platform_probe(struct platform_device *pdev)
+{
+	struct intel_spi_boardinfo *info;
+	struct intel_spi *ispi;
+	struct resource *mem;
+
+	info = dev_get_platdata(&pdev->dev);
+	if (!info)
+		return -EINVAL;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	ispi = intel_spi_probe(&pdev->dev, mem, info);
+	if (IS_ERR(ispi))
+		return PTR_ERR(ispi);
+
+	platform_set_drvdata(pdev, ispi);
+	return 0;
+}
+
+static int intel_spi_platform_remove(struct platform_device *pdev)
+{
+	struct intel_spi *ispi = platform_get_drvdata(pdev);
+
+	return intel_spi_remove(ispi);
+}
+
+static struct platform_driver intel_spi_platform_driver = {
+	.probe = intel_spi_platform_probe,
+	.remove = intel_spi_platform_remove,
+	.driver = {
+		.name = "intel-spi",
+	},
+};
+
+module_platform_driver(intel_spi_platform_driver);
+
+MODULE_DESCRIPTION("Intel PCH/PCU SPI flash platform driver");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:intel-spi");
diff --git a/drivers/mtd/spi-nor/intel-spi.c b/drivers/mtd/spi-nor/intel-spi.c
new file mode 100644
index 000000000000..1adb3d7f640d
--- /dev/null
+++ b/drivers/mtd/spi-nor/intel-spi.c
@@ -0,0 +1,748 @@
+/*
+ * Intel PCH/PCU SPI flash driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@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 version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/spi-nor.h>
+#include <linux/platform_data/intel-spi.h>
+
+#include "intel-spi.h"
+
+/* Offsets are from @ispi->base */
+#define BFPREG				0x00
+
+#define HSFSTS_CTL			0x04
+#define HSFSTS_CTL_FSMIE		BIT(31)
+#define HSFSTS_CTL_FDBC_SHIFT		24
+#define HSFSTS_CTL_FDBC_MASK		(0x3f << HSFSTS_CTL_FDBC_SHIFT)
+
+#define HSFSTS_CTL_FCYCLE_SHIFT		17
+#define HSFSTS_CTL_FCYCLE_MASK		(0x0f << HSFSTS_CTL_FCYCLE_SHIFT)
+/* HW sequencer opcodes */
+#define HSFSTS_CTL_FCYCLE_READ		(0x00 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_WRITE		(0x02 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_ERASE_4K	(0x03 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_ERASE_64K	(0x04 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_RDID		(0x06 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_WRSR		(0x07 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_RDSR		(0x08 << HSFSTS_CTL_FCYCLE_SHIFT)
+
+#define HSFSTS_CTL_FGO			BIT(16)
+#define HSFSTS_CTL_FLOCKDN		BIT(15)
+#define HSFSTS_CTL_FDV			BIT(14)
+#define HSFSTS_CTL_SCIP			BIT(5)
+#define HSFSTS_CTL_AEL			BIT(2)
+#define HSFSTS_CTL_FCERR		BIT(1)
+#define HSFSTS_CTL_FDONE		BIT(0)
+
+#define FADDR				0x08
+#define DLOCK				0x0c
+#define FDATA(n)			(0x10 + ((n) * 4))
+
+#define FRACC				0x50
+
+#define FREG(n)				(0x54 + ((n) * 4))
+#define FREG_BASE_MASK			0x3fff
+#define FREG_LIMIT_SHIFT		16
+#define FREG_LIMIT_MASK			(0x03fff << FREG_LIMIT_SHIFT)
+
+#define PR(n)				(0x74 + ((n) * 4))
+#define PR_WPE				BIT(31)
+#define PR_LIMIT_SHIFT			16
+#define PR_LIMIT_MASK			(0x3fff << PR_LIMIT_SHIFT)
+#define PR_RPE				BIT(15)
+#define PR_BASE_MASK			0x3fff
+/* Last PR is GPR0 */
+#define PR_NUM				(5 + 1)
+
+/* Offsets are from @ispi->sregs */
+#define SSFSTS_CTL			0x00
+#define SSFSTS_CTL_FSMIE		BIT(23)
+#define SSFSTS_CTL_DS			BIT(22)
+#define SSFSTS_CTL_DBC_SHIFT		16
+#define SSFSTS_CTL_SPOP			BIT(11)
+#define SSFSTS_CTL_ACS			BIT(10)
+#define SSFSTS_CTL_SCGO			BIT(9)
+#define SSFSTS_CTL_COP_SHIFT		12
+#define SSFSTS_CTL_FRS			BIT(7)
+#define SSFSTS_CTL_DOFRS		BIT(6)
+#define SSFSTS_CTL_AEL			BIT(4)
+#define SSFSTS_CTL_FCERR		BIT(3)
+#define SSFSTS_CTL_FDONE		BIT(2)
+#define SSFSTS_CTL_SCIP			BIT(0)
+
+#define PREOP_OPTYPE			0x04
+#define OPMENU0				0x08
+#define OPMENU1				0x0c
+
+/* CPU specifics */
+#define SSFSTS_CTL_BYT			0x90
+#define BCR_BYT				0xfc
+#define BCR_BYT_WPD			BIT(0)
+#define FREG_NUM_BYT			5
+
+#define SSFSTS_CTL_LPT			0x90
+#define FREG_NUM_LPT			5
+
+#define SSFSTS_CTL_BXT			0xa0
+#define FREG_NUM_BXT			12
+
+#define INTEL_SPI_TIMEOUT		5000 /* ms */
+
+/**
+ * struct intel_spi - Driver private data
+ * @dev: Device pointer
+ * @info: Pointer to board specific info
+ * @nor: SPI NOR layer structure
+ * @base: Beginning of MMIO space
+ * @sregs: Start of software sequencer registers
+ * @nregions: Maximum number of regions
+ * @writeable: Is the chip writeable
+ * @swseq: Use SW sequencer in register reads/writes
+ * @opcodes: Opcodes which are supported. This are programmed by BIOS
+ *           before it locks down the controller.
+ * @preopcodes: Preopcodes which are supported.
+ */
+struct intel_spi {
+	struct device *dev;
+	const struct intel_spi_boardinfo *info;
+	struct spi_nor nor;
+	void __iomem *base;
+	void __iomem *sregs;
+	size_t nregions;
+	bool writeable;
+	bool swseq;
+	u8 opcodes[8];
+	u8 preopcodes[2];
+};
+
+static bool writeable;
+module_param(writeable, bool, 0);
+MODULE_PARM_DESC(writeable, "Enable write access to SPI flash chip (default=0)");
+
+static void intel_spi_dump_regs(struct intel_spi *ispi)
+{
+	u32 value;
+	int i;
+
+	dev_dbg(ispi->dev, "BFPREG=0x%08x\n", readl(ispi->base + BFPREG));
+
+	value = readl(ispi->base + HSFSTS_CTL);
+	dev_dbg(ispi->dev, "HSFSTS_CTL=0x%08x\n", value);
+	if (value & HSFSTS_CTL_FLOCKDN)
+		dev_dbg(ispi->dev, "-> Locked\n");
+
+	dev_dbg(ispi->dev, "FADDR=0x%08x\n", readl(ispi->base + FADDR));
+	dev_dbg(ispi->dev, "DLOCK=0x%08x\n", readl(ispi->base + DLOCK));
+
+	for (i = 0; i < 16; i++)
+		dev_dbg(ispi->dev, "FDATA(%d)=0x%08x\n",
+			i, readl(ispi->base + FDATA(i)));
+
+	dev_dbg(ispi->dev, "FRACC=0x%08x\n", readl(ispi->base + FRACC));
+
+	for (i = 0; i < ispi->nregions; i++)
+		dev_dbg(ispi->dev, "FREG(%d)=0x%08x\n", i,
+			readl(ispi->base + FREG(i)));
+	for (i = 0; i < PR_NUM; i++)
+		dev_dbg(ispi->dev, "PR(%d)=0x%08x\n", i,
+			readl(ispi->base + PR(i)));
+
+	value = readl(ispi->sregs + SSFSTS_CTL);
+	dev_dbg(ispi->dev, "SSFSTS_CTL=0x%08x\n", value);
+	dev_dbg(ispi->dev, "PREOP_OPTYPE=0x%08x\n",
+		readl(ispi->sregs + PREOP_OPTYPE));
+	dev_dbg(ispi->dev, "OPMENU0=0x%08x\n", readl(ispi->sregs + OPMENU0));
+	dev_dbg(ispi->dev, "OPMENU1=0x%08x\n", readl(ispi->sregs + OPMENU1));
+
+	if (ispi->info->type == INTEL_SPI_BYT)
+		dev_dbg(ispi->dev, "BCR=0x%08x\n", readl(ispi->base + BCR_BYT));
+
+	dev_dbg(ispi->dev, "Protected regions:\n");
+	for (i = 0; i < PR_NUM; i++) {
+		u32 base, limit;
+
+		value = readl(ispi->base + PR(i));
+		if (!(value & (PR_WPE | PR_RPE)))
+			continue;
+
+		limit = (value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
+		base = value & PR_BASE_MASK;
+
+		dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x [%c%c]\n",
+			 i, base << 12, (limit << 12) | 0xfff,
+			 value & PR_WPE ? 'W' : '.',
+			 value & PR_RPE ? 'R' : '.');
+	}
+
+	dev_dbg(ispi->dev, "Flash regions:\n");
+	for (i = 0; i < ispi->nregions; i++) {
+		u32 region, base, limit;
+
+		region = readl(ispi->base + FREG(i));
+		base = region & FREG_BASE_MASK;
+		limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
+
+		if (base > limit || (i > 0 && limit == 0))
+			dev_dbg(ispi->dev, " %02d disabled\n", i);
+		else
+			dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x\n",
+				 i, base << 12, (limit << 12) | 0xfff);
+	}
+
+	dev_dbg(ispi->dev, "Using %cW sequencer for register access\n",
+		ispi->swseq ? 'S' : 'H');
+}
+
+/* Reads max 64 bytes from the device fifo */
+static int intel_spi_read_block(struct intel_spi *ispi, void *buf, size_t size)
+{
+	size_t bytes;
+	int i = 0;
+
+	if (size > 64)
+		return -EINVAL;
+
+	while (size > 0) {
+		bytes = min_t(size_t, size, 4);
+		memcpy_fromio(buf, ispi->base + FDATA(i++), bytes);
+		size -= bytes;
+		buf += bytes;
+	}
+
+	return 0;
+}
+
+/* Writes max 64 bytes to the device fifo */
+static int intel_spi_write_block(struct intel_spi *ispi, const void *buf,
+				 size_t size)
+{
+	size_t bytes;
+	int i = 0;
+
+	if (size > 64)
+		return -EINVAL;
+
+	while (size > 0) {
+		bytes = min_t(size_t, size, 4);
+		memcpy_toio(ispi->base + FDATA(i++), buf, bytes);
+		size -= bytes;
+		buf += bytes;
+	}
+
+	return 0;
+}
+
+static int intel_spi_wait_hw_busy(struct intel_spi *ispi)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(INTEL_SPI_TIMEOUT);
+	u32 hwstat;
+
+	while (!time_after(jiffies, timeout)) {
+		hwstat = readl(ispi->base + HSFSTS_CTL);
+		if (!(hwstat & HSFSTS_CTL_SCIP))
+			return 0;
+		cond_resched();
+	}
+
+	return -ETIMEDOUT;
+}
+
+static int intel_spi_wait_sw_busy(struct intel_spi *ispi)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(INTEL_SPI_TIMEOUT);
+	u32 swstat;
+
+	while (!time_after(jiffies, timeout)) {
+		swstat = readl(ispi->sregs + SSFSTS_CTL);
+		if (!(swstat & SSFSTS_CTL_SCIP))
+			return 0;
+		cond_resched();
+	}
+
+	return -ETIMEDOUT;
+}
+
+static int intel_spi_init(struct intel_spi *ispi)
+{
+	u32 opmenu0, opmenu1, val;
+	int i;
+
+	switch (ispi->info->type) {
+	case INTEL_SPI_BYT:
+		ispi->sregs = ispi->base + SSFSTS_CTL_BYT;
+		ispi->nregions = FREG_NUM_BYT;
+
+		if (writeable) {
+			/* Disable write protection */
+			val = readl(ispi->base + BCR_BYT);
+			if (!(val & BCR_BYT_WPD)) {
+				val |= BCR_BYT_WPD;
+				writel(val, ispi->base + BCR_BYT);
+				val = readl(ispi->base + BCR_BYT);
+			}
+
+			ispi->writeable = !!(val & BCR_BYT_WPD);
+		}
+
+		break;
+
+	case INTEL_SPI_LPT:
+		ispi->sregs = ispi->base + SSFSTS_CTL_LPT;
+		ispi->nregions = FREG_NUM_LPT;
+		break;
+
+	case INTEL_SPI_BXT:
+		ispi->sregs = ispi->base + SSFSTS_CTL_BXT;
+		ispi->nregions = FREG_NUM_BXT;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	/* Disable #SMI generation */
+	val = readl(ispi->base + HSFSTS_CTL);
+	val &= ~HSFSTS_CTL_FSMIE;
+	writel(val, ispi->base + HSFSTS_CTL);
+
+	/*
+	 * BIOS programs allowed opcodes and then locks down the register.
+	 * So read back what opcodes it decided to support. That's the set
+	 * we are going to support as well.
+	 */
+	opmenu0 = readl(ispi->sregs + OPMENU0);
+	opmenu1 = readl(ispi->sregs + OPMENU1);
+
+	/*
+	 * Some controllers can only do basic operations using hardware
+	 * sequencer. All other operations are supposed to be carried out
+	 * using software sequencer. If we find that BIOS has programmed
+	 * opcodes for the software sequencer we use that over the hardware
+	 * sequencer.
+	 */
+	if (opmenu0 && opmenu1) {
+		for (i = 0; i < ARRAY_SIZE(ispi->opcodes) / 2; i++) {
+			ispi->opcodes[i] = opmenu0 >> i * 8;
+			ispi->opcodes[i + 4] = opmenu1 >> i * 8;
+		}
+
+		val = readl(ispi->sregs + PREOP_OPTYPE);
+		ispi->preopcodes[0] = val;
+		ispi->preopcodes[1] = val >> 8;
+
+		/* Disable #SMI generation from SW sequencer */
+		val = readl(ispi->sregs + SSFSTS_CTL);
+		val &= ~SSFSTS_CTL_FSMIE;
+		writel(val, ispi->sregs + SSFSTS_CTL);
+
+		ispi->swseq = true;
+	}
+
+	intel_spi_dump_regs(ispi);
+
+	return 0;
+}
+
+static int intel_spi_opcode_index(struct intel_spi *ispi, u8 opcode)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ispi->opcodes); i++)
+		if (ispi->opcodes[i] == opcode)
+			return i;
+	return -EINVAL;
+}
+
+static int intel_spi_hw_cycle(struct intel_spi *ispi, u8 opcode, u8 *buf,
+			      int len)
+{
+	u32 val, status;
+	int ret;
+
+	val = readl(ispi->base + HSFSTS_CTL);
+	val &= ~(HSFSTS_CTL_FCYCLE_MASK | HSFSTS_CTL_FDBC_MASK);
+
+	switch (opcode) {
+	case SPINOR_OP_RDID:
+		val |= HSFSTS_CTL_FCYCLE_RDID;
+		break;
+	case SPINOR_OP_WRSR:
+		val |= HSFSTS_CTL_FCYCLE_WRSR;
+		break;
+	case SPINOR_OP_RDSR:
+		val |= HSFSTS_CTL_FCYCLE_RDSR;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	val |= (len - 1) << HSFSTS_CTL_FDBC_SHIFT;
+	val |= HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+	val |= HSFSTS_CTL_FGO;
+	writel(val, ispi->base + HSFSTS_CTL);
+
+	ret = intel_spi_wait_hw_busy(ispi);
+	if (ret)
+		return ret;
+
+	status = readl(ispi->base + HSFSTS_CTL);
+	if (status & HSFSTS_CTL_FCERR)
+		return -EIO;
+	else if (status & HSFSTS_CTL_AEL)
+		return -EACCES;
+
+	return 0;
+}
+
+static int intel_spi_sw_cycle(struct intel_spi *ispi, u8 opcode, u8 *buf,
+			      int len)
+{
+	u32 val, status;
+	int ret;
+
+	ret = intel_spi_opcode_index(ispi, opcode);
+	if (ret < 0)
+		return ret;
+
+	val = (len << SSFSTS_CTL_DBC_SHIFT) | SSFSTS_CTL_DS;
+	val |= ret << SSFSTS_CTL_COP_SHIFT;
+	val |= SSFSTS_CTL_FCERR | SSFSTS_CTL_FDONE;
+	val |= SSFSTS_CTL_SCGO;
+	writel(val, ispi->sregs + SSFSTS_CTL);
+
+	ret = intel_spi_wait_sw_busy(ispi);
+	if (ret)
+		return ret;
+
+	status = readl(ispi->base + SSFSTS_CTL);
+	if (status & SSFSTS_CTL_FCERR)
+		return -EIO;
+	else if (status & SSFSTS_CTL_AEL)
+		return -EACCES;
+
+	return 0;
+}
+
+static int intel_spi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+	struct intel_spi *ispi = nor->priv;
+	int ret;
+
+	/* Address of the first chip */
+	writel(0, ispi->base + FADDR);
+
+	if (ispi->swseq)
+		ret = intel_spi_sw_cycle(ispi, opcode, buf, len);
+	else
+		ret = intel_spi_hw_cycle(ispi, opcode, buf, len);
+
+	if (ret)
+		return ret;
+
+	return intel_spi_read_block(ispi, buf, len);
+}
+
+static int intel_spi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+	struct intel_spi *ispi = nor->priv;
+	int ret;
+
+	/*
+	 * This is handled with atomic operation and preop code in Intel
+	 * controller so skip it here now.
+	 */
+	if (opcode == SPINOR_OP_WREN)
+		return 0;
+
+	writel(0, ispi->base + FADDR);
+
+	/* Write the value beforehand */
+	ret = intel_spi_write_block(ispi, buf, len);
+	if (ret)
+		return ret;
+
+	if (ispi->swseq)
+		return intel_spi_sw_cycle(ispi, opcode, buf, len);
+	return intel_spi_hw_cycle(ispi, opcode, buf, len);
+}
+
+static int intel_spi_read(struct spi_nor *nor, loff_t from, size_t len,
+			  size_t *retlen, u_char *read_buf)
+{
+	struct intel_spi *ispi = nor->priv;
+	size_t block_size;
+	u32 val, status;
+	ssize_t ret;
+
+	while (len > 0) {
+		block_size = min_t(size_t, len, 64);
+
+		writel(from, ispi->base + FADDR);
+
+		val = readl(ispi->base + HSFSTS_CTL);
+		val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+		val &= ~HSFSTS_CTL_FDBC_MASK;
+		val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
+		val &= ~HSFSTS_CTL_FCYCLE_MASK;
+		val |= HSFSTS_CTL_FCYCLE_READ;
+		val |= HSFSTS_CTL_FGO;
+		writel(val, ispi->base + HSFSTS_CTL);
+
+		ret = intel_spi_wait_hw_busy(ispi);
+		if (ret)
+			return ret;
+
+		status = readl(ispi->base + HSFSTS_CTL);
+		if (status & HSFSTS_CTL_FCERR)
+			ret = -EIO;
+		else if (status & HSFSTS_CTL_AEL)
+			ret = -EACCES;
+
+		if (ret < 0) {
+			dev_err(ispi->dev, "read error: %llx: %#x\n", from,
+				status);
+			return ret;
+		}
+
+		ret = intel_spi_read_block(ispi, read_buf, block_size);
+		if (ret)
+			return ret;
+
+		len -= block_size;
+		from += block_size;
+		*retlen += block_size;
+		read_buf += block_size;
+	}
+
+	return 0;
+}
+
+static void intel_spi_write(struct spi_nor *nor, loff_t to, size_t len,
+			    size_t *retlen, const u_char *write_buf)
+{
+	struct intel_spi *ispi = nor->priv;
+	size_t block_size;
+	u32 val, status;
+	int ret;
+
+	while (len > 0) {
+		block_size = min_t(size_t, len, 64);
+
+		writel(to, ispi->base + FADDR);
+
+		val = readl(ispi->base + HSFSTS_CTL);
+		val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+		val &= ~HSFSTS_CTL_FDBC_MASK;
+		val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
+		val &= ~HSFSTS_CTL_FCYCLE_MASK;
+		val |= HSFSTS_CTL_FCYCLE_WRITE;
+
+		/* Write enable */
+		if (ispi->preopcodes[1] == SPINOR_OP_WREN)
+			val |= SSFSTS_CTL_SPOP;
+		val |= SSFSTS_CTL_ACS;
+		writel(val, ispi->base + HSFSTS_CTL);
+
+		ret = intel_spi_write_block(ispi, write_buf, block_size);
+		if (ret) {
+			dev_err(ispi->dev, "failed to write block\n");
+			break;
+		}
+
+		/* Start the write now */
+		val = readl(ispi->base + HSFSTS_CTL);
+		writel(val | HSFSTS_CTL_FGO, ispi->base + HSFSTS_CTL);
+
+		ret = intel_spi_wait_hw_busy(ispi);
+		if (ret) {
+			dev_err(ispi->dev, "timeout\n");
+			break;
+		}
+
+		status = readl(ispi->base + HSFSTS_CTL);
+		if (status & (HSFSTS_CTL_FCERR | HSFSTS_CTL_AEL)) {
+			/* There is not much we can do but to report an error */
+			dev_err(ispi->dev, "write error: %llx: %#x\n", to,
+				status);
+		}
+
+		len -= block_size;
+		to += block_size;
+		*retlen += block_size;
+		write_buf += block_size;
+	}
+}
+
+static int intel_spi_erase(struct spi_nor *nor, loff_t offs)
+{
+	struct intel_spi *ispi = nor->priv;
+	u32 val, status;
+	int ret;
+
+	writel(offs, ispi->base + FADDR);
+
+	val = readl(ispi->base + HSFSTS_CTL);
+	val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+	val &= ~HSFSTS_CTL_FDBC_MASK;
+	val &= ~HSFSTS_CTL_FCYCLE_MASK;
+	if (nor->mtd.erasesize == 4096)
+		val |= HSFSTS_CTL_FCYCLE_ERASE_4K;
+	else
+		val |= HSFSTS_CTL_FCYCLE_ERASE_64K;
+	val |= HSFSTS_CTL_FGO;
+	writel(val, ispi->base + HSFSTS_CTL);
+
+	ret = intel_spi_wait_hw_busy(ispi);
+	if (ret)
+		return ret;
+
+	status = readl(ispi->base + HSFSTS_CTL);
+	if (status & HSFSTS_CTL_FCERR)
+		return -EIO;
+	else if (status & HSFSTS_CTL_AEL)
+		return -EACCES;
+
+	return 0;
+}
+
+static bool intel_spi_is_protected(const struct intel_spi *ispi,
+				   unsigned int base, unsigned int limit)
+{
+	int i;
+
+	for (i = 0; i < PR_NUM; i++) {
+		u32 pr_base, pr_limit, pr_value;
+
+		pr_value = readl(ispi->base + PR(i));
+		if (!(pr_value & (PR_WPE | PR_RPE)))
+			continue;
+
+		pr_limit = (pr_value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
+		pr_base = pr_value & PR_BASE_MASK;
+
+		if (pr_base >= base && pr_limit <= limit)
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * There will be a single partition holding all enabled flash regions. We
+ * call this "BIOS".
+ */
+static void intel_spi_fill_partition(struct intel_spi *ispi,
+				     struct mtd_partition *part)
+{
+	u64 end;
+	int i;
+
+	memset(part, 0, sizeof(*part));
+
+	/* Start from the mandatory descriptor region */
+	part->size = 4096;
+	part->name = "BIOS";
+
+	/*
+	 * Now try to find where this partition ends based on the flash
+	 * region registers.
+	 */
+	for (i = 1; i < ispi->nregions; i++) {
+		u32 region, base, limit;
+
+		region = readl(ispi->base + FREG(i));
+		base = region & FREG_BASE_MASK;
+		limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
+
+		if (base > limit || limit == 0)
+			continue;
+
+		/*
+		 * If any of the regions have protection bits set, make the
+		 * whole partition read-only to be on the safe side.
+		 */
+		if (intel_spi_is_protected(ispi, base, limit))
+			ispi->writeable = 0;
+
+		end = (limit << 12) + 4096;
+		if (end > part->size)
+			part->size = end;
+	}
+}
+
+struct intel_spi *intel_spi_probe(struct device *dev,
+	struct resource *mem, const struct intel_spi_boardinfo *info)
+{
+	struct mtd_partition part;
+	struct intel_spi *ispi;
+	int ret;
+
+	if (!info || !mem)
+		return ERR_PTR(-EINVAL);
+
+	ispi = devm_kzalloc(dev, sizeof(*ispi), GFP_KERNEL);
+	if (!ispi)
+		return ERR_PTR(-ENOMEM);
+
+	ispi->base = devm_ioremap_resource(dev, mem);
+	if (IS_ERR(ispi->base))
+		return ispi->base;
+
+	ispi->dev = dev;
+	ispi->info = info;
+	ispi->writeable = info->writeable;
+
+	ret = intel_spi_init(ispi);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ispi->nor.dev = ispi->dev;
+	ispi->nor.priv = ispi;
+	ispi->nor.read_reg = intel_spi_read_reg;
+	ispi->nor.write_reg = intel_spi_write_reg;
+	ispi->nor.read = intel_spi_read;
+	ispi->nor.write = intel_spi_write;
+	ispi->nor.erase = intel_spi_erase;
+
+	ret = spi_nor_scan(&ispi->nor, NULL, SPI_NOR_NORMAL);
+	if (ret) {
+		dev_info(dev, "failed to locate the chip\n");
+		return ERR_PTR(ret);
+	}
+
+	intel_spi_fill_partition(ispi, &part);
+
+	/* Prevent writes if not explicitly enabled */
+	if (!ispi->writeable || !writeable)
+		ispi->nor.mtd.flags &= ~MTD_WRITEABLE;
+
+	ret = mtd_device_parse_register(&ispi->nor.mtd, NULL, NULL, &part, 1);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return ispi;
+}
+EXPORT_SYMBOL_GPL(intel_spi_probe);
+
+int intel_spi_remove(struct intel_spi *ispi)
+{
+	return mtd_device_unregister(&ispi->nor.mtd);
+}
+EXPORT_SYMBOL_GPL(intel_spi_remove);
+
+MODULE_DESCRIPTION("Intel PCH/PCU SPI flash core driver");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mtd/spi-nor/intel-spi.h b/drivers/mtd/spi-nor/intel-spi.h
new file mode 100644
index 000000000000..5ab7dc250050
--- /dev/null
+++ b/drivers/mtd/spi-nor/intel-spi.h
@@ -0,0 +1,24 @@
+/*
+ * Intel PCH/PCU SPI flash driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@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 version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef INTEL_SPI_H
+#define INTEL_SPI_H
+
+#include <linux/platform_data/intel-spi.h>
+
+struct intel_spi;
+struct resource;
+
+struct intel_spi *intel_spi_probe(struct device *dev,
+	struct resource *mem, const struct intel_spi_boardinfo *info);
+int intel_spi_remove(struct intel_spi *ispi);
+
+#endif /* INTEL_SPI_H */
diff --git a/include/linux/platform_data/intel-spi.h b/include/linux/platform_data/intel-spi.h
new file mode 100644
index 000000000000..942b0c3f8f08
--- /dev/null
+++ b/include/linux/platform_data/intel-spi.h
@@ -0,0 +1,31 @@
+/*
+ * Intel PCH/PCU SPI flash driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@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 version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef INTEL_SPI_PDATA_H
+#define INTEL_SPI_PDATA_H
+
+enum intel_spi_type {
+	INTEL_SPI_BYT = 1,
+	INTEL_SPI_LPT,
+	INTEL_SPI_BXT,
+};
+
+/**
+ * struct intel_spi_boardinfo - Board specific data for Intel SPI driver
+ * @type: Type which this controller is compatible with
+ * @writeable: The chip is writeable
+ */
+struct intel_spi_boardinfo {
+	enum intel_spi_type type;
+	bool writeable;
+};
+
+#endif /* INTEL_SPI_PDATA_H */
-- 
2.8.1

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 2/3] mfd: lpc_ich: Add support for SPI serial flash host controller
  2016-06-14 11:43 [PATCH 0/3] spi-nor: Add support for Intel SPI serial flash controller Mika Westerberg
  2016-06-14 11:43 ` [PATCH 1/3] " Mika Westerberg
@ 2016-06-14 11:43 ` Mika Westerberg
  2016-06-15 15:38   ` Lee Jones
  2016-06-14 11:43 ` [PATCH 3/3] mfd: lpc_ich: Add support for Intel Apollo Lake SoC Mika Westerberg
  2 siblings, 1 reply; 6+ messages in thread
From: Mika Westerberg @ 2016-06-14 11:43 UTC (permalink / raw)
  To: linux-mtd
  Cc: Brian Norris, David Woodhouse, Lee Jones, Peter Tyser,
	key.seong.lim, Mika Westerberg, linux-kernel

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       | 97 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/lpc_ich.h |  3 ++
 2 files changed, 100 insertions(+)

diff --git a/drivers/mfd/lpc_ich.c b/drivers/mfd/lpc_ich.c
index bd3aa4578346..39b7731d769a 100644
--- a/drivers/mfd/lpc_ich.c
+++ b/drivers/mfd/lpc_ich.c
@@ -83,6 +83,13 @@
 #define ACPIBASE_GCS_OFF	0x3410
 #define ACPIBASE_GCS_END	0x3414
 
+#define SPIBASE_BYT		0x54
+#define SPIBASE_BYT_EN		BIT(1)
+
+#define SPIBASE_LPT		0x3800
+#define BCR			0xdc
+#define BCR_WPD			BIT(0)
+
 #define GPIOBASE_ICH0		0x58
 #define GPIOCTRL_ICH0		0x5C
 #define GPIOBASE_ICH6		0x48
@@ -133,6 +140,12 @@ 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 +160,14 @@ 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 +514,12 @@ 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 +533,7 @@ 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 +542,12 @@ 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",
@@ -875,6 +901,15 @@ static void lpc_ich_finalize_gpio_cell(struct pci_dev *dev)
 	cell->pdata_size = sizeof(struct lpc_ich_info);
 }
 
+static void lpc_ich_finalize_spi_cell(struct pci_dev *dev,
+				     struct intel_spi_boardinfo *info)
+{
+	struct mfd_cell *cell = &lpc_ich_spi_cell;
+
+	cell->platform_data = info;
+	cell->pdata_size = sizeof(*info);
+}
+
 /*
  * We don't check for resource conflict globally. There are 2 or 3 independent
  * GPIO groups and it's enough to have access to one of these to instantiate
@@ -1050,6 +1085,62 @@ 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 (lpc_chipset_info[priv->chipset].spi_type) {
+	case INTEL_SPI_BYT:
+		pci_read_config_dword(dev, SPIBASE_BYT, &spi_base);
+		if (spi_base & SPIBASE_BYT_EN) {
+			res->start = spi_base &= 0xfffffe00;
+			res->end = res->start + 512 - 1;
+		}
+		break;
+
+	case INTEL_SPI_LPT:
+		pci_read_config_dword(dev, RCBABASE, &rcba);
+		if (rcba & 1) {
+			spi_base = rcba & 0xfffffe00;
+			res->start = spi_base + SPIBASE_LPT;
+			res->end = res->start + 512 - 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_finalize_spi_cell(dev, info);
+	return mfd_add_devices(&dev->dev, -1, &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 +1184,12 @@ 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

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH 3/3] mfd: lpc_ich: Add support for Intel Apollo Lake SoC
  2016-06-14 11:43 [PATCH 0/3] spi-nor: Add support for Intel SPI serial flash controller Mika Westerberg
  2016-06-14 11:43 ` [PATCH 1/3] " Mika Westerberg
  2016-06-14 11:43 ` [PATCH 2/3] mfd: lpc_ich: Add support for SPI serial flash host controller Mika Westerberg
@ 2016-06-14 11:43 ` Mika Westerberg
  2 siblings, 0 replies; 6+ messages in thread
From: Mika Westerberg @ 2016-06-14 11:43 UTC (permalink / raw)
  To: linux-mtd
  Cc: Brian Norris, David Woodhouse, Lee Jones, Peter Tyser,
	key.seong.lim, Mika Westerberg, linux-kernel

Intel Apollo Lake SoC exposes serial SPI flash through the LPC device. The
SPI flash host controller is not discoverable through PCI config cycles
because P2SB (function 0 of the device 13) is hidden by the BIOS. We unhide
the device briefly in order to read BAR 0 of the SPI host controller.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/mfd/lpc_ich.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/mfd/lpc_ich.c b/drivers/mfd/lpc_ich.c
index 39b7731d769a..d7f6d6728975 100644
--- a/drivers/mfd/lpc_ich.c
+++ b/drivers/mfd/lpc_ich.c
@@ -56,6 +56,7 @@
  *	document number TBD : Wildcat Point-LP
  *	document number TBD : 9 Series
  *	document number TBD : Lewisburg
+ *	document number TBD : Apollo Lake SoC
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -237,6 +238,7 @@ enum lpc_chipsets {
 	LPC_BRASWELL,	/* Braswell SoC */
 	LPC_LEWISBURG,	/* Lewisburg */
 	LPC_9S,		/* 9 Series */
+	LPC_APL,	/* Apollo Lake SoC */
 };
 
 static struct lpc_ich_info lpc_chipset_info[] = {
@@ -557,6 +559,10 @@ static struct lpc_ich_info lpc_chipset_info[] = {
 		.name = "9 Series",
 		.iTCO_version = 2,
 	},
+	[LPC_APL] = {
+		.name = "Apollo Lake SoC",
+		.spi_type = INTEL_SPI_BXT,
+	},
 };
 
 /*
@@ -705,6 +711,7 @@ static const struct pci_device_id lpc_ich_ids[] = {
 	{ PCI_VDEVICE(INTEL, 0x3b14), LPC_3420},
 	{ PCI_VDEVICE(INTEL, 0x3b16), LPC_3450},
 	{ PCI_VDEVICE(INTEL, 0x5031), LPC_EP80579},
+	{ PCI_VDEVICE(INTEL, 0x5ae8), LPC_APL},
 	{ PCI_VDEVICE(INTEL, 0x8c40), LPC_LPT},
 	{ PCI_VDEVICE(INTEL, 0x8c41), LPC_LPT},
 	{ PCI_VDEVICE(INTEL, 0x8c42), LPC_LPT},
@@ -1129,6 +1136,36 @@ static int lpc_ich_init_spi(struct pci_dev *dev)
 		}
 		break;
 
+	case INTEL_SPI_BXT: {
+		unsigned int p2sb = PCI_DEVFN(13, 0);
+		unsigned int spi = PCI_DEVFN(13, 2);
+		struct pci_bus *bus = dev->bus;
+
+		/*
+		 * The P2SB is hidden by BIOS and we need to unhide it in
+		 * order to read BAR of the SPI flash device. Once that is
+		 * done we hide it again.
+		 */
+		pci_bus_write_config_byte(bus, p2sb, 0xe1, 0x0);
+		pci_bus_read_config_dword(bus, spi, PCI_BASE_ADDRESS_0,
+					  &spi_base);
+		if (spi_base != ~0) {
+			res->start = spi_base & 0xfffffff0;
+			res->end = res->start + SZ_4K - 1;
+
+			pci_bus_read_config_dword(bus, spi, BCR, &bcr);
+			if (!(bcr & BCR_WPD)) {
+				bcr |= BCR_WPD;
+				pci_bus_write_config_dword(bus, spi, BCR, bcr);
+				pci_bus_read_config_dword(bus, spi, BCR, &bcr);
+			}
+			info->writeable = !!(bcr & BCR_WPD);
+		}
+
+		pci_bus_write_config_byte(dev->bus, p2sb, 0xe1, 0x1);
+		break;
+	}
+
 	default:
 		return -EINVAL;
 	}
-- 
2.8.1

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 2/3] mfd: lpc_ich: Add support for SPI serial flash host controller
  2016-06-14 11:43 ` [PATCH 2/3] mfd: lpc_ich: Add support for SPI serial flash host controller Mika Westerberg
@ 2016-06-15 15:38   ` Lee Jones
  2016-06-16  7:55     ` Mika Westerberg
  0 siblings, 1 reply; 6+ messages in thread
From: Lee Jones @ 2016-06-15 15:38 UTC (permalink / raw)
  To: Mika Westerberg
  Cc: linux-mtd, Brian Norris, David Woodhouse, Peter Tyser,
	key.seong.lim, linux-kernel

On Tue, 14 Jun 2016, Mika Westerberg wrote:

> 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       | 97 +++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/mfd/lpc_ich.h |  3 ++
>  2 files changed, 100 insertions(+)
> 
> diff --git a/drivers/mfd/lpc_ich.c b/drivers/mfd/lpc_ich.c
> index bd3aa4578346..39b7731d769a 100644
> --- a/drivers/mfd/lpc_ich.c
> +++ b/drivers/mfd/lpc_ich.c
> @@ -83,6 +83,13 @@
>  #define ACPIBASE_GCS_OFF	0x3410
>  #define ACPIBASE_GCS_END	0x3414
>  
> +#define SPIBASE_BYT		0x54
> +#define SPIBASE_BYT_EN		BIT(1)
> +
> +#define SPIBASE_LPT		0x3800
> +#define BCR			0xdc
> +#define BCR_WPD			BIT(0)
> +
>  #define GPIOBASE_ICH0		0x58
>  #define GPIOCTRL_ICH0		0x5C
>  #define GPIOBASE_ICH6		0x48
> @@ -133,6 +140,12 @@ 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 +160,14 @@ 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 +514,12 @@ 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 +533,7 @@ 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 +542,12 @@ 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",
> @@ -875,6 +901,15 @@ static void lpc_ich_finalize_gpio_cell(struct pci_dev *dev)
>  	cell->pdata_size = sizeof(struct lpc_ich_info);
>  }
>  
> +static void lpc_ich_finalize_spi_cell(struct pci_dev *dev,
> +				     struct intel_spi_boardinfo *info)
> +{
> +	struct mfd_cell *cell = &lpc_ich_spi_cell;
> +
> +	cell->platform_data = info;
> +	cell->pdata_size = sizeof(*info);
> +}

This call doesn't appear to offer anything.  In fact, it looks like it
adds more lines than is required.

>  /*
>   * We don't check for resource conflict globally. There are 2 or 3 independent
>   * GPIO groups and it's enough to have access to one of these to instantiate
> @@ -1050,6 +1085,62 @@ 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 (lpc_chipset_info[priv->chipset].spi_type) {

The type now exists in info->type.  I suggest you use that here
instead.

> +	case INTEL_SPI_BYT:
> +		pci_read_config_dword(dev, SPIBASE_BYT, &spi_base);
> +		if (spi_base & SPIBASE_BYT_EN) {
> +			res->start = spi_base &= 0xfffffe00;
> +			res->end = res->start + 512 - 1;

Define all of these magic numbers.

> +		}
> +		break;
> +
> +	case INTEL_SPI_LPT:
> +		pci_read_config_dword(dev, RCBABASE, &rcba);
> +		if (rcba & 1) {
> +			spi_base = rcba & 0xfffffe00;
> +			res->start = spi_base + SPIBASE_LPT;
> +			res->end = res->start + 512 - 1;

And here.

> +			/*
> +			 * 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);

I'd prefer if you didn't do that here.  In fact, is there any
technical reason why you can't move the entirety of this function into
the SPI NOR driver?

> +		}
> +		break;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	if (!res->start)
> +		return -ENODEV;
> +
> +	lpc_ich_finalize_spi_cell(dev, info);
> +	return mfd_add_devices(&dev->dev, -1, &lpc_ich_spi_cell, 1, NULL, 0,

Use the includes provided.  Look at other drivers for examples.

> +			       NULL);
> +}
> +
>  static int lpc_ich_probe(struct pci_dev *dev,
>  				const struct pci_device_id *id)
>  {
> @@ -1093,6 +1184,12 @@ 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;
>  };
>  

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 2/3] mfd: lpc_ich: Add support for SPI serial flash host controller
  2016-06-15 15:38   ` Lee Jones
@ 2016-06-16  7:55     ` Mika Westerberg
  0 siblings, 0 replies; 6+ messages in thread
From: Mika Westerberg @ 2016-06-16  7:55 UTC (permalink / raw)
  To: Lee Jones
  Cc: linux-mtd, Brian Norris, David Woodhouse, Peter Tyser,
	key.seong.lim, linux-kernel

On Wed, Jun 15, 2016 at 04:38:35PM +0100, Lee Jones wrote:
> On Tue, 14 Jun 2016, Mika Westerberg wrote:
> 
> > 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       | 97 +++++++++++++++++++++++++++++++++++++++++++++
> >  include/linux/mfd/lpc_ich.h |  3 ++
> >  2 files changed, 100 insertions(+)
> > 
> > diff --git a/drivers/mfd/lpc_ich.c b/drivers/mfd/lpc_ich.c
> > index bd3aa4578346..39b7731d769a 100644
> > --- a/drivers/mfd/lpc_ich.c
> > +++ b/drivers/mfd/lpc_ich.c
> > @@ -83,6 +83,13 @@
> >  #define ACPIBASE_GCS_OFF	0x3410
> >  #define ACPIBASE_GCS_END	0x3414
> >  
> > +#define SPIBASE_BYT		0x54
> > +#define SPIBASE_BYT_EN		BIT(1)
> > +
> > +#define SPIBASE_LPT		0x3800
> > +#define BCR			0xdc
> > +#define BCR_WPD			BIT(0)
> > +
> >  #define GPIOBASE_ICH0		0x58
> >  #define GPIOCTRL_ICH0		0x5C
> >  #define GPIOBASE_ICH6		0x48
> > @@ -133,6 +140,12 @@ 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 +160,14 @@ 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 +514,12 @@ 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 +533,7 @@ 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 +542,12 @@ 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",
> > @@ -875,6 +901,15 @@ static void lpc_ich_finalize_gpio_cell(struct pci_dev *dev)
> >  	cell->pdata_size = sizeof(struct lpc_ich_info);
> >  }
> >  
> > +static void lpc_ich_finalize_spi_cell(struct pci_dev *dev,
> > +				     struct intel_spi_boardinfo *info)
> > +{
> > +	struct mfd_cell *cell = &lpc_ich_spi_cell;
> > +
> > +	cell->platform_data = info;
> > +	cell->pdata_size = sizeof(*info);
> > +}
> 
> This call doesn't appear to offer anything.  In fact, it looks like it
> adds more lines than is required.

Yeah, it follows what we do with other parts but I can do this in
lpc_ich_init_spi() instead.

> >  /*
> >   * We don't check for resource conflict globally. There are 2 or 3 independent
> >   * GPIO groups and it's enough to have access to one of these to instantiate
> > @@ -1050,6 +1085,62 @@ 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 (lpc_chipset_info[priv->chipset].spi_type) {
> 
> The type now exists in info->type.  I suggest you use that here
> instead.

OK

> > +	case INTEL_SPI_BYT:
> > +		pci_read_config_dword(dev, SPIBASE_BYT, &spi_base);
> > +		if (spi_base & SPIBASE_BYT_EN) {
> > +			res->start = spi_base &= 0xfffffe00;
> > +			res->end = res->start + 512 - 1;
> 
> Define all of these magic numbers.

OK

> > +		}
> > +		break;
> > +
> > +	case INTEL_SPI_LPT:
> > +		pci_read_config_dword(dev, RCBABASE, &rcba);
> > +		if (rcba & 1) {
> > +			spi_base = rcba & 0xfffffe00;
> > +			res->start = spi_base + SPIBASE_LPT;
> > +			res->end = res->start + 512 - 1;
> 
> And here.

OK

> > +			/*
> > +			 * 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);
> 
> I'd prefer if you didn't do that here.  In fact, is there any
> technical reason why you can't move the entirety of this function into
> the SPI NOR driver?

Unfortunately, I was not able to figure better way. With the exception
of Baytrail (BYT) these bits are part of the PCI device and you need to
access them using PCI config cycles. It gets worse with Broxton (BXT)
where this all is part of "hidden" P2SB PCI device.

I thought about adding a callback which can be used to toggle the bit
but that would require passing pointer to the PCI device (and for
Broxton, I don't know what we would pass, to be honest).

> > +		}
> > +		break;
> > +
> > +	default:
> > +		return -EINVAL;
> > +	}
> > +
> > +	if (!res->start)
> > +		return -ENODEV;
> > +
> > +	lpc_ich_finalize_spi_cell(dev, info);
> > +	return mfd_add_devices(&dev->dev, -1, &lpc_ich_spi_cell, 1, NULL, 0,
> 
> Use the includes provided.  Look at other drivers for examples.

Okay.

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2016-06-16  7:56 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-06-14 11:43 [PATCH 0/3] spi-nor: Add support for Intel SPI serial flash controller Mika Westerberg
2016-06-14 11:43 ` [PATCH 1/3] " Mika Westerberg
2016-06-14 11:43 ` [PATCH 2/3] mfd: lpc_ich: Add support for SPI serial flash host controller Mika Westerberg
2016-06-15 15:38   ` Lee Jones
2016-06-16  7:55     ` Mika Westerberg
2016-06-14 11:43 ` [PATCH 3/3] mfd: lpc_ich: Add support for Intel Apollo Lake SoC Mika Westerberg

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).