i2c: intel_i2c: SMBus driver PCI addition (e.g. BayTrail)

This patch adds support for the SMBus block read/write functionality.
Other protocols like the SMBus quick command need to get added
if this is needed.

This patch also removed the SMBus related defines from the Ivybridge
pch.h header. As they are integrated in this driver and should be
used from here. This change is added in this patch to avoid compile
breakage to keep the source git bisectable.

Tested on a congatec BayTrail board to configure the SMSC2513 USB
hub.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Bin Meng <bmeng.cn@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Heiko Schocher <hs@denx.de>
Cc: George McCollister <george.mccollister@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 269 insertions, 21 deletions

diff --git a/drivers/i2c/intel_i2c.c b/drivers/i2c/intel_i2c.c
index ba80662..a0182dc 100644
--- a/drivers/i2c/intel_i2c.c
+++ b/drivers/i2c/intel_i2c.c
@@ -2,54 +2,290 @@
  * Copyright (c) 2015 Google, Inc
  * Written by Simon Glass <sjg@chromium.org>
  *
+ * SMBus block read/write support added by Stefan Roese:
+ * Copyright (C) 2016 Stefan Roese <sr@denx.de>
+ *
  * SPDX-License-Identifier:     GPL-2.0+
  */
 
 #include <common.h>
 #include <dm.h>
 #include <i2c.h>
+#include <pci.h>
 #include <asm/io.h>
-#include <asm/arch/pch.h>
 
-int intel_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
+/* PCI Configuration Space (D31:F3): SMBus */
+#define SMB_BASE		0x20
+#define HOSTC			0x40
+#define  HST_EN			(1 << 0)
+#define SMB_RCV_SLVA		0x09
+
+/* SMBus I/O bits. */
+#define SMBHSTSTAT		0x0
+#define SMBHSTCTL		0x2
+#define SMBHSTCMD		0x3
+#define SMBXMITADD		0x4
+#define SMBHSTDAT0		0x5
+#define SMBHSTDAT1		0x6
+#define SMBBLKDAT		0x7
+#define SMBTRNSADD		0x9
+#define SMBSLVDATA		0xa
+#define SMBAUXCTL		0xd
+#define SMLINK_PIN_CTL		0xe
+#define SMBUS_PIN_CTL		0xf
+
+/* I801 Hosts Status register bits */
+#define SMBHSTSTS_BYTE_DONE	0x80
+#define SMBHSTSTS_INUSE_STS	0x40
+#define SMBHSTSTS_SMBALERT_STS	0x20
+#define SMBHSTSTS_FAILED	0x10
+#define SMBHSTSTS_BUS_ERR	0x08
+#define SMBHSTSTS_DEV_ERR	0x04
+#define SMBHSTSTS_INTR		0x02
+#define SMBHSTSTS_HOST_BUSY	0x01
+
+/* I801 Host Control register bits */
+#define SMBHSTCNT_INTREN	0x01
+#define SMBHSTCNT_KILL		0x02
+#define SMBHSTCNT_LAST_BYTE	0x20
+#define SMBHSTCNT_START		0x40
+#define SMBHSTCNT_PEC_EN	0x80	/* ICH3 and later */
+
+/* Auxiliary control register bits, ICH4+ only */
+#define SMBAUXCTL_CRC		1
+#define SMBAUXCTL_E32B		2
+
+#define SMBUS_TIMEOUT	100	/* 100 ms */
+
+struct intel_i2c {
+	u32 base;
+	int running;
+};
+
+static int smbus_wait_until_ready(u32 base)
 {
-	return -ENOSYS;
+	unsigned long ts;
+	u8 byte;
+
+	ts = get_timer(0);
+	do {
+		byte = inb(base + SMBHSTSTAT);
+		if (!(byte & 1))
+			return 0;
+	} while (get_timer(ts) < SMBUS_TIMEOUT);
+
+	return -ETIMEDOUT;
 }
 
-int intel_i2c_probe_chip(struct udevice *bus, uint chip_addr, uint chip_flags)
+static int smbus_wait_until_done(u32 base)
 {
-	return -ENOSYS;
+	unsigned long ts;
+	u8 byte;
+
+	ts = get_timer(0);
+	do {
+		byte = inb(base + SMBHSTSTAT);
+		if (!((byte & 1) || (byte & ~((1 << 6) | (1 << 0))) == 0))
+			return 0;
+	} while (get_timer(ts) < SMBUS_TIMEOUT);
+
+	return -ETIMEDOUT;
 }
 
-int intel_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
+static int smbus_block_read(u32 base, u8 dev, u8 *buffer,
+			    int offset, int len)
 {
+	u8 buf_temp[32];
+	int count;
+	int i;
+
+	debug("%s (%d): dev=0x%x offs=0x%x len=0x%x\n",
+	      __func__, __LINE__, dev, offset, len);
+	if (smbus_wait_until_ready(base) < 0)
+		return -ETIMEDOUT;
+
+	/* Setup transaction */
+
+	/* Reset the data buffer index */
+	inb(base + SMBHSTCTL);
+
+	/* Set the device I'm talking too */
+	outb(((dev & 0x7f) << 1) | 1, base + SMBXMITADD);
+	/* Set the command/address... */
+	outb(offset & 0xff, base + SMBHSTCMD);
+	/* Set up for a block read */
+	outb((inb(base + SMBHSTCTL) & (~(0x7) << 2)) | (0x5 << 2),
+	     (base + SMBHSTCTL));
+	/* Clear any lingering errors, so the transaction will run */
+	outb(inb(base + SMBHSTSTAT), base + SMBHSTSTAT);
+
+	/* Start the command */
+	outb((inb(base + SMBHSTCTL) | SMBHSTCNT_START), base + SMBHSTCTL);
+
+	/* Poll for transaction completion */
+	if (smbus_wait_until_done(base) < 0) {
+		printf("SMBUS read transaction timeout (dev=0x%x)\n", dev);
+		return -ETIMEDOUT;
+	}
+
+	count = inb(base + SMBHSTDAT0);
+	debug("%s (%d): count=%d (len=%d)\n", __func__, __LINE__, count, len);
+	if (count == 0) {
+		debug("ERROR: len=0 on read\n");
+		return -EIO;
+	}
+
+	if (count < len) {
+		debug("ERROR: too few bytes read\n");
+		return -EIO;
+	}
+
+	if (count > 32) {
+		debug("ERROR: count=%d too high\n", count);
+		return -EIO;
+	}
+
+	/* Read all available bytes from buffer */
+	for (i = 0; i < count; i++)
+		buf_temp[i] = inb(base + SMBBLKDAT);
+
+	memcpy(buffer, buf_temp, len);
+
+	/* Return results of transaction */
+	if (!(inb(base + SMBHSTSTAT) & SMBHSTSTS_INTR))
+		return -EIO;
+
 	return 0;
 }
 
-static int intel_i2c_probe(struct udevice *dev)
+static int smbus_block_write(u32 base, u8 dev, u8 *buffer,
+			     int offset, int len)
 {
+	int i;
+
+	debug("%s (%d): dev=0x%x offs=0x%x len=0x%x\n",
+	      __func__, __LINE__, dev, offset, len);
+	if (smbus_wait_until_ready(base) < 0)
+		return -ETIMEDOUT;
+
+	/* Setup transaction */
+	/* Set the device I'm talking too */
+	outb(((dev & 0x7f) << 1) & ~0x01, base + SMBXMITADD);
+	/* Set the command/address... */
+	outb(offset, base + SMBHSTCMD);
+	/* Set up for a block write */
+	outb((inb(base + SMBHSTCTL) & (~(0x7) << 2)) | (0x5 << 2),
+	     (base + SMBHSTCTL));
+	/* Clear any lingering errors, so the transaction will run */
+	outb(inb(base + SMBHSTSTAT), base + SMBHSTSTAT);
+
+	/* Write count in DAT0 register */
+	outb(len, base + SMBHSTDAT0);
+
+	/* Write data bytes... */
+	for (i = 0; i < len; i++)
+		outb(*buffer++, base + SMBBLKDAT);
+
+	/* Start the command */
+	outb((inb(base + SMBHSTCTL) | SMBHSTCNT_START), base + SMBHSTCTL);
+
+	/* Poll for transaction completion */
+	if (smbus_wait_until_done(base) < 0) {
+		printf("SMBUS write transaction timeout (dev=0x%x)\n", dev);
+		return -ETIMEDOUT;
+	}
+
+	/* Return results of transaction */
+	if (!(inb(base + SMBHSTSTAT) & SMBHSTSTS_INTR))
+		return -EIO;
+
+	return 0;
+}
+
+static int intel_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
+{
+	struct intel_i2c *i2c = dev_get_priv(bus);
+	struct i2c_msg *dmsg, *omsg, dummy;
+
+	debug("i2c_xfer: %d messages\n", nmsgs);
+
+	memset(&dummy, 0, sizeof(struct i2c_msg));
+
 	/*
-	 * So far this is just setup code for ivybridge SMbus. When we have
-	 * a full I2C driver this may need to be moved, generalised or made
-	 * dependant on a particular compatible string.
-	 *
-	 * Set SMBus I/O base
+	 * We expect either two messages (one with an offset and one with the
+	 * actucal data) or one message (just data)
 	 */
-	dm_pci_write_config32(dev, SMB_BASE,
-			      SMBUS_IO_BASE | PCI_BASE_ADDRESS_SPACE_IO);
+	if (nmsgs > 2 || nmsgs == 0) {
+		debug("%s: Only one or two messages are supported", __func__);
+		return -EIO;
+	}
+
+	omsg = nmsgs == 1 ? &dummy : msg;
+	dmsg = nmsgs == 1 ? msg : msg + 1;
+
+	if (dmsg->flags & I2C_M_RD)
+		return smbus_block_read(i2c->base, dmsg->addr, &dmsg->buf[0],
+					omsg->buf[0], dmsg->len);
+	else
+		return smbus_block_write(i2c->base, dmsg->addr, &dmsg->buf[1],
+					 dmsg->buf[0], dmsg->len - 1);
+}
+
+static int intel_i2c_probe_chip(struct udevice *bus, uint chip_addr,
+				uint chip_flags)
+{
+	struct intel_i2c *i2c = dev_get_priv(bus);
+	u8 buf[4];
+
+	return smbus_block_read(i2c->base, chip_addr, buf, 0, 1);
+}
+
+static int intel_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
+{
+	return 0;
+}
+
+static int intel_i2c_probe(struct udevice *dev)
+{
+	struct intel_i2c *priv = dev_get_priv(dev);
+	u32 base;
+
+	/* Save base address from PCI BAR */
+	priv->base = (u32)dm_pci_map_bar(dev, PCI_BASE_ADDRESS_4,
+					 PCI_REGION_IO);
+	base = priv->base;
 
 	/* Set SMBus enable. */
 	dm_pci_write_config8(dev, HOSTC, HST_EN);
 
-	/* Set SMBus I/O space enable. */
-	dm_pci_write_config16(dev, PCI_COMMAND, PCI_COMMAND_IO);
+	/* Disable interrupts */
+	outb(inb(base + SMBHSTCTL) & ~SMBHSTCNT_INTREN, base + SMBHSTCTL);
 
-	/* Disable interrupt generation. */
-	outb(0, SMBUS_IO_BASE + SMBHSTCTL);
+	/* Set 32-byte data buffer mode */
+	outb(inb(base + SMBAUXCTL) | SMBAUXCTL_E32B, base + SMBAUXCTL);
 
-	/* Clear any lingering errors, so transactions can run. */
-	outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT);
-	debug("SMBus controller enabled\n");
+	return 0;
+}
+
+static int intel_i2c_bind(struct udevice *dev)
+{
+	static int num_cards __attribute__ ((section(".data")));
+	char name[20];
+
+	/* Create a unique device name for PCI type devices */
+	if (device_is_on_pci_bus(dev)) {
+		/*
+		 * ToDo:
+		 * Setting req_seq in the driver is probably not recommended.
+		 * But without a DT alias the number is not configured. And
+		 * using this driver is impossible for PCIe I2C devices.
+		 * This can be removed, once a better (correct) way for this
+		 * is found and implemented.
+		 */
+		dev->req_seq = num_cards;
+		sprintf(name, "intel_i2c#%u", num_cards++);
+		device_set_name(dev, name);
+	}
 
 	return 0;
 }
@@ -70,5 +306,17 @@ U_BOOT_DRIVER(intel_i2c) = {
 	.id	= UCLASS_I2C,
 	.of_match = intel_i2c_ids,
 	.ops	= &intel_i2c_ops,
+	.priv_auto_alloc_size = sizeof(struct intel_i2c),
+	.bind	= intel_i2c_bind,
 	.probe	= intel_i2c_probe,
 };
+
+static struct pci_device_id intel_smbus_pci_supported[] = {
+	/* Intel BayTrail SMBus on the PCI bus */
+	{ PCI_VDEVICE(INTEL, 0x0f12) },
+	/* Intel IvyBridge (Panther Point PCH) SMBus on the PCI bus */
+	{ PCI_VDEVICE(INTEL, 0x1e22) },
+	{},
+};
+
+U_BOOT_PCI_DEVICE(intel_i2c, intel_smbus_pci_supported);