Message-Id: <1344008145-14579-2-git-send-email-amaury.decreme@gmail.com>
Date:	Fri,  3 Aug 2012 17:35:44 +0200
From:	Amaury Decrême <amaury.decreme@...il.com>
To:	khali@...ux-fr.org, ben-linux@...ff.org, w.sang@...gutronix.de,
	rob@...dley.net
Cc:	jeffrey.t.kirsher@...el.com, akpm@...ux-foundation.org,
	davem@...emloft.net, gregkh@...uxfoundation.org, joe@...ches.com,
	ralf@...ux-mips.org, dirk.brandewie@...il.com,
	jayachandranc@...logicmicro.com, linux-i2c@...r.kernel.org,
	linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
	Amaury Decrême <amaury.decreme@...il.com>
Subject: [PATCH v2 1/2] I2C: SIS964: Bus driver - Driver

This patchs contains the SMBus driver for SIS964.
Built with Sis datasheets and by forking the SIS630 driver.

Signed-off-by: Amaury Decrême <amaury.decreme@...il.com>
---
 drivers/i2c/busses/i2c-sis964.c |  578 +++++++++++++++++++++++++++++++++++++++
 1 files changed, 578 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/busses/i2c-sis964.c

diff --git a/drivers/i2c/busses/i2c-sis964.c b/drivers/i2c/busses/i2c-sis964.c
new file mode 100644
index 0000000..91b6ec9
--- /dev/null
+++ b/drivers/i2c/busses/i2c-sis964.c
@@ -0,0 +1,578 @@
+/*
+    Copyright (c) 2012 Amaury Decrême <amaury.decreme@...il.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; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/*
+   Changes:
+   11.08.2011
+	Fork of original i2c-sis630 - Alexander Malysh <amalysh@....de>
+	Adapted for SiS964 with datasheets
+			- Amaury Decrême <amaury.decreme@...il.com>
+*/
+
+/*
+   Supports:
+	SIS 964
+
+   Note: we assume there can only be one device, with one SMBus interface.
+*/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/acpi.h>
+#include <linux/io.h>
+
+#define PCI_DEVICE_ID_SI_964	0x0964
+
+
+/* SIS964 SMBus registers */
+#define SMB_STS			0xE0	/* status */
+#define SMB_EN			0xE1	/* status enable */
+#define SMB_CNT			0xE2	/* Control */
+#define SMBHOST_CNT		0xE3	/* Host Control */
+#define SMB_ADDR		0xE4	/* Address */
+#define SMB_CMD			0xE5	/* Command */
+#define SMB_PERRCHK		0xE6	/* Packet Error Check */
+#define SMB_COUNT		0xE7	/* Byte Count */
+#define SMB_BYTE		0xE8	/* ~0x8F data byte field */
+#define SMBDEV_ADDR		0xF0	/* Device Address */
+#define SMB_DB0			0xF1	/* Device byte0 */
+#define SMB_DB1			0xF2	/* Device byte1 */
+#define SMB_SAA			0xF3	/* Host slave alias address */
+#define SMB_PCOUNT		0xF4	/* processed byte count */
+
+
+/* SMB_STS register */
+#define SMBALT_STS		0x80	/* Slave alert */
+#define BYTE_DONE_STS		0x10	/* Byte Done Status / Block Array */
+#define SMBMAS_STS		0x08	/* Host Master */
+#define SMBCOL_STS		0x04	/* Collision */
+#define SMBERR_STS		0x02	/* Device error */
+
+/* SMB_CNT register */
+#define SMBCLK_SEL		0x20	/* Host master clock selection */
+#define SMB_PROBE		0x02	/* Bus Probe */
+#define SMB_HOSTBUSY		0x01	/* Host Busy */
+
+/* SMBHOST_CNT register */
+#define SMB_KILL		0x20	/* Kill */
+#define SMB_START		0x10	/* Start */
+#define SMB_PTL			0x07	/* Command Protocol */
+
+
+/* SMB_ADDR register */
+#define SMB_ADDRESS		0xFE	/* Adress */
+#define SMB_RW			0x01	/* Read/Write */
+
+
+/* SMB_BYTE register */
+#define SMB_BYTE0		0xFF	/* Byte 0 */
+#define SMB_BYTE1		0xFF00	/* Byte 1 */
+
+/* register count for request_region */
+#define SIS964_SMB_IOREGION	21
+
+/* PCI address constants */
+/* acpi base address register  */
+#define SIS964_ACPI_BASE_REG	0x74
+/* bios control register */
+#define SIS964_BIOS_CTL_REG	0x40
+
+/* Other settings */
+#define MAX_TIMEOUT		500
+
+/* SIS964 constants */
+#define SIS964_QUICK		0x00
+#define SIS964_BYTE		0x01
+#define SIS964_BYTE_DATA	0x02
+#define SIS964_WORD_DATA	0x03
+#define SIS964_PCALL		0x04
+#define SIS964_BLOCK_DATA	0x05
+
+static struct pci_driver sis964_driver;
+
+/* insmod parameters */
+static bool low_clock;
+static bool force;
+module_param(low_clock, bool, 0);
+MODULE_PARM_DESC(low_clock, "Set Host Master Clock to 28KHz (default 56KHz).");
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force, "Forcibly enable the SIS964. DANGEROUS!");
+
+/* acpi base address */
+static unsigned short acpi_base;
+
+/* supported chips */
+static int supported[] = {
+	PCI_DEVICE_ID_SI_964,
+	0 /* terminates the list */
+};
+
+static inline u8 sis964_read(u8 reg)
+{
+	return inb(acpi_base + reg);
+}
+
+static inline void sis964_write(u8 reg, u8 data)
+{
+	outb(data, acpi_base + reg);
+}
+
+static int sis964_transaction_start(struct i2c_adapter *adap,
+					int ptl, u8 *oldclock)
+{
+	int tmp = 0;
+
+	/* Clear status register */
+	sis964_write(SMB_STS, 0xFF);
+
+	/* Make sure the SMBus host is ready to start transmitting. */
+	tmp = sis964_read(SMB_CNT);
+	if (tmp & (SMB_PROBE | SMB_HOSTBUSY)) {
+		dev_dbg(&adap->dev,
+			"Bus busy (status 0x%02x). Killing transaction.\n",
+			tmp);
+
+		sis964_write(SMBHOST_CNT, SMB_KILL);
+
+		return -EBUSY;
+	}
+
+	/* Set Host Master Clock to 28KHz if requested */
+	if (low_clock) {
+		*oldclock = sis964_read(SMB_CNT);
+		sis964_write(SMB_CNT, SMBCLK_SEL);
+	}
+
+	/* start the transaction by setting bit start and protocol */
+	sis964_write(SMBHOST_CNT, SMB_START | (ptl & SMB_PTL));
+
+	return 0;
+}
+
+static int sis964_transaction_wait(struct i2c_adapter *adap, int ptl)
+{
+	int tmp = 0, timeout = 0;
+
+	/* Wait 30us, valid for 28Khz and 56Khz */
+	udelay(30);
+
+	tmp = sis964_read(SMB_STS);
+	if (!(tmp & SMB_PROBE) && (tmp & SMB_HOSTBUSY)) {
+		dev_dbg(&adap->dev,
+			"Host busy (status 0x%02x). Restarting transaction.\n",
+			tmp);
+		sis964_write(SMBHOST_CNT, SMB_KILL);
+		return -EAGAIN;
+	}
+
+	while (!(ptl == SIS964_BLOCK_DATA && (tmp & BYTE_DONE_STS))
+		&& !(tmp & (SMBMAS_STS | SMBCOL_STS | SMBERR_STS))
+		&& (timeout++ < MAX_TIMEOUT)) {
+
+		/* Datasheets: wait 4ms max at 28Khz and
+		 * 2ms max at 56Khz for 8 bytes */
+		if (low_clock)
+			udelay(4000);
+		else
+			udelay(2000);
+		tmp = sis964_read(SMB_STS);
+	}
+
+	/* If the SMBus is still busy, we give up */
+	if (timeout > MAX_TIMEOUT) {
+		dev_dbg(&adap->dev,
+			"Bus Timeout (status 0x%02x)!\n", tmp);
+		return -ETIMEDOUT;
+	}
+
+	if (tmp & SMBERR_STS) {
+		dev_dbg(&adap->dev,
+			"Failed bus transaction (status 0x%02x)!\n", tmp);
+		return -ENXIO;
+	}
+
+	if (tmp & SMBCOL_STS) {
+		dev_err(&adap->dev,
+			"Bus collision (status 0x%02x)!\n", tmp);
+		sis964_write(SMB_STS, tmp & ~SMBCOL_STS);
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+static void sis964_transaction_end(u8 oldclock)
+{
+	/* clear all status "sticky" bits */
+	sis964_write(SMB_STS, 0xFF);
+
+	/* restore old Host Master Clock if low_clock is set */
+	if (low_clock)
+		sis964_write(SMB_CNT, oldclock & SMBCLK_SEL);
+}
+
+static int sis964_transaction(struct i2c_adapter *adap, int ptl)
+{
+	int tmp = 0, timeout = 0;
+	u8 oldclock = 0;
+
+	do {
+		tmp = sis964_transaction_start(adap, ptl, &oldclock);
+		if (tmp)
+			return tmp;
+
+		tmp = sis964_transaction_wait(adap, ptl);
+		sis964_transaction_end(oldclock);
+	} while (tmp == -EAGAIN && timeout++ < MAX_TIMEOUT);
+
+	if (timeout > MAX_TIMEOUT) {
+		dev_dbg(&adap->dev, "Bus timeout !\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int sis964_block_data_read(struct i2c_adapter *adap,
+				union i2c_smbus_data *data)
+{
+	int i, len = 0, tmp = 0;
+	u8 oldclock = 0;
+
+	data->block[0] = len = 0;
+
+	tmp = sis964_transaction_start(adap, SIS964_BLOCK_DATA, &oldclock);
+	if (tmp)
+		return tmp;
+
+	do {
+		tmp = sis964_transaction_wait(adap, SIS964_BLOCK_DATA);
+		if (tmp) {
+			dev_dbg(&adap->dev, "Transaction wait failed\n");
+			break;
+		}
+
+		/* if this first transaction then read byte count */
+		if (len == 0)
+			data->block[0] = sis964_read(SMB_COUNT);
+
+		if (data->block[0] > 32)
+			data->block[0] = 32;
+
+		dev_dbg(&adap->dev, "Block data read len=0x%x\n",
+			data->block[0]);
+
+		for (i = 0; i < 8 && len < data->block[0]; i++, len++) {
+			dev_dbg(&adap->dev, "Read i=%d len=%d\n", i, len);
+			data->block[len+1] = sis964_read(SMB_BYTE+i);
+		}
+
+		/* clear BYTE_DONE_STS */
+		sis964_write(SMB_STS, BYTE_DONE_STS);
+	} while (len < data->block[0]);
+
+	sis964_transaction_end(oldclock);
+
+	return 0;
+}
+
+
+static int sis964_block_data_write(struct i2c_adapter *adap,
+				union i2c_smbus_data *data)
+{
+
+	int i, len = 0, tmp = 0;
+	u8 oldclock = 0;
+
+	len = data->block[0];
+	if (len < 0)
+		len = 0;
+	else if (len > 32)
+		len = 32;
+
+	sis964_write(SMB_COUNT, len);
+
+	for (i = 1; i <= len; i++) {
+		dev_dbg(&adap->dev, "Set data 0x%02x\n", data->block[i]);
+
+		/* set data */
+		sis964_write(SMB_BYTE+(i-1)%8, data->block[i]);
+		if (i == 8 || (len < 8 && i == len)) {
+
+			/* first transaction */
+			tmp = sis964_transaction_start(adap, SIS964_BLOCK_DATA,
+					&oldclock);
+			if (tmp)
+				return tmp;
+
+		} else if ((i-1)%8 == 7 || i == len) {
+			if (i > 8) {
+				dev_dbg(&adap->dev,
+				"Clear smbary_sts len=%d i=%d\n", len, i);
+
+				/*
+				   If this is not first transaction,
+				   we must clear sticky bit.
+				   clear BYTE_DONE-STS
+				*/
+				sis964_write(SMB_STS, BYTE_DONE_STS);
+			}
+			tmp = sis964_transaction_wait(adap,
+					SIS964_BLOCK_DATA);
+			if (tmp) {
+				dev_dbg(&adap->dev,
+					"Transaction wait failed\n");
+				break;
+			}
+		}
+	}
+
+	sis964_transaction_end(oldclock);
+
+	return 0;
+}
+
+static int sis964_block_data(struct i2c_adapter *adap,
+				union i2c_smbus_data *data, int read_write)
+{
+	if (read_write == I2C_SMBUS_WRITE)
+		return sis964_block_data_write(adap, data);
+	else
+		return sis964_block_data_read(adap, data);
+}
+
+/* Return negative errno on error. */
+static s32 sis964_access(struct i2c_adapter *adap, u16 addr,
+			 unsigned short flags, char read_write,
+			 u8 command, int ptl, union i2c_smbus_data *data)
+{
+	int tmp = 0;
+
+	switch (ptl) {
+	case I2C_SMBUS_QUICK:
+		sis964_write(SMB_ADDR, ((addr << 1) & SMB_ADDRESS) |
+					(read_write & SMB_RW));
+		ptl = SIS964_QUICK;
+		break;
+	case I2C_SMBUS_BYTE:
+		sis964_write(SMB_ADDR, ((addr << 1) & SMB_ADDRESS) |
+					(read_write & SMB_RW));
+		if (read_write == I2C_SMBUS_WRITE)
+			sis964_write(SMB_CMD, command);
+		ptl = SIS964_BYTE;
+		break;
+	case I2C_SMBUS_BYTE_DATA:
+		sis964_write(SMB_ADDR, ((addr << 1) & SMB_ADDRESS) |
+					(read_write & SMB_RW));
+		sis964_write(SMB_CMD, command);
+		if (read_write == I2C_SMBUS_WRITE)
+			sis964_write(SMB_BYTE, data->byte);
+		ptl = SIS964_BYTE_DATA;
+		break;
+	case I2C_SMBUS_PROC_CALL:
+	case I2C_SMBUS_WORD_DATA:
+		sis964_write(SMB_ADDR, ((addr << 1) & SMB_ADDRESS) |
+					(read_write & SMB_RW));
+		sis964_write(SMB_CMD, command);
+		if (read_write == I2C_SMBUS_WRITE) {
+			sis964_write(SMB_BYTE, data->word & SMB_BYTE0);
+			sis964_write(SMB_BYTE + 1,
+					(data->word & SMB_BYTE1) >> 8);
+		}
+		ptl = (ptl == I2C_SMBUS_PROC_CALL ?
+				SIS964_PCALL : SIS964_WORD_DATA);
+		break;
+	case I2C_SMBUS_BLOCK_DATA:
+		sis964_write(SMB_ADDR, ((addr << 1) & SMB_ADDRESS) |
+					(read_write & SMB_RW));
+		sis964_write(SMB_CMD, command);
+		ptl = SIS964_BLOCK_DATA;
+		return sis964_block_data(adap, data, read_write);
+	default:
+		dev_warn(&adap->dev, "Unsupported transaction %d\n",
+			 ptl);
+		return -EOPNOTSUPP;
+	}
+
+	tmp = sis964_transaction(adap, ptl);
+	if (tmp)
+		return tmp;
+
+	if (ptl != SIS964_PCALL &&
+		(read_write == I2C_SMBUS_WRITE || ptl == SIS964_QUICK)) {
+		return 0;
+	}
+
+	switch (ptl) {
+	case SIS964_BYTE:
+	case SIS964_BYTE_DATA:
+		data->byte = sis964_read(SMB_BYTE);
+		break;
+	case SIS964_PCALL:
+	case SIS964_WORD_DATA:
+		data->word = sis964_read(SMB_BYTE) +
+				(sis964_read(SMB_BYTE + 1) << 8);
+		break;
+	}
+
+	return 0;
+}
+
+static u32 sis964_func(struct i2c_adapter *adapter)
+{
+	/* SMBus Command protocol supported */
+	return I2C_FUNC_SMBUS_QUICK |		/* Quick command */
+		I2C_FUNC_SMBUS_BYTE |		/* Send/Receive Byte */
+		I2C_FUNC_SMBUS_BYTE_DATA |	/* Read/Write Byte Data */
+		I2C_FUNC_SMBUS_WORD_DATA |	/* Read/Write Word Data */
+		I2C_FUNC_SMBUS_PROC_CALL |	/* Process Call */
+		I2C_FUNC_SMBUS_BLOCK_DATA;	/* Read/Write Block Data */
+}
+
+static int __devinit sis964_setup(struct pci_dev *sis964_dev)
+{
+	unsigned char b;
+	struct pci_dev *dummy = NULL;
+	int tmp = 0, i;
+
+	/* check for supported SiS devices */
+	for (i = 0; supported[i] > 0 && dummy == NULL; i++)
+		dummy = pci_get_device(PCI_VENDOR_ID_SI, supported[i], dummy);
+
+	if (dummy) {
+		pci_dev_put(dummy);
+	} else if (force) {
+		dev_err(&sis964_dev->dev,
+			"WARNING: Can't detect SIS964 compatible device, but "
+			"loading because of force option enabled\n");
+	} else {
+		dev_err(&sis964_dev->dev,
+			"WARNING: Can't detect SIS964 compatible device!\n");
+		return -ENODEV;
+	}
+
+
+	/*
+	   Enable ACPI first , so we can accsess reg 74-75
+	   in acpi io space and read acpi base addr
+	*/
+	if (pci_read_config_byte(sis964_dev, SIS964_BIOS_CTL_REG, &b)) {
+		dev_err(&sis964_dev->dev, "Error: Can't read bios ctl reg\n");
+		return -ENODEV;
+	}
+	/* if ACPI already enabled , do nothing */
+	if (!(b & 0x80) &&
+	    pci_write_config_byte(sis964_dev, SIS964_BIOS_CTL_REG, b | 0x80)) {
+		dev_err(&sis964_dev->dev, "Error: Can't enable ACPI\n");
+		return -ENODEV;
+	}
+
+	/* Determine the ACPI base address */
+	if (pci_read_config_word(sis964_dev, SIS964_ACPI_BASE_REG,
+				&acpi_base)) {
+		dev_err(&sis964_dev->dev,
+				"Error: Can't determine ACPI base address\n");
+		return -ENODEV;
+	}
+
+	dev_dbg(&sis964_dev->dev, "ACPI base at 0x%04x\n", acpi_base);
+
+	tmp = acpi_check_region(acpi_base + SMB_STS, SIS964_SMB_IOREGION,
+				   sis964_driver.name);
+	if (tmp) {
+		acpi_base = 0;
+		return -ENODEV;
+	}
+
+	/* Everything is happy, let's grab the memory and set things up. */
+	if (!request_region(acpi_base + SMB_STS, SIS964_SMB_IOREGION,
+			    sis964_driver.name)) {
+		dev_err(&sis964_dev->dev,
+			"SMBus registers 0x%04x-0x%04x already in use!\n",
+			acpi_base + SMB_STS, acpi_base + SMB_SAA);
+		acpi_base = 0;
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+
+static const struct i2c_algorithm smbus_algorithm = {
+	.smbus_xfer	= sis964_access,
+	.functionality	= sis964_func,
+};
+
+static struct i2c_adapter sis964_adapter = {
+	.owner		= THIS_MODULE,
+	.class		= I2C_CLASS_HWMON | I2C_CLASS_SPD,
+	.algo		= &smbus_algorithm,
+};
+
+static DEFINE_PCI_DEVICE_TABLE(sis964_ids) = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_SI, PCI_DEVICE_ID_SI_964) },
+	{ 0 }
+};
+
+MODULE_DEVICE_TABLE(pci, sis964_ids);
+
+static int __devinit sis964_probe(struct pci_dev *dev,
+					const struct pci_device_id *id)
+{
+	if (sis964_setup(dev)) {
+		dev_err(&dev->dev,
+		       "SIS964 comp. bus not detected, module not inserted.\n");
+		return -ENODEV;
+	}
+
+	/* set up the sysfs linkage to our parent device */
+	sis964_adapter.dev.parent = &dev->dev;
+
+	snprintf(sis964_adapter.name, sizeof(sis964_adapter.name),
+		 "SMBus SIS964 adapter at %04xh", acpi_base + SMB_STS);
+
+	return i2c_add_adapter(&sis964_adapter);
+}
+
+static void __devexit sis964_remove(struct pci_dev *dev)
+{
+	if (acpi_base) {
+		i2c_del_adapter(&sis964_adapter);
+		release_region(acpi_base + SMB_STS, SIS964_SMB_IOREGION);
+		acpi_base = 0;
+	}
+}
+
+
+static struct pci_driver sis964_driver = {
+	.name		= "sis964_smbus",
+	.id_table	= sis964_ids,
+	.probe		= sis964_probe,
+	.remove		= __devexit_p(sis964_remove),
+};
+
+module_pci_driver(sis964_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Amaury Decrême <amaury.decreme@...il.com>");
+MODULE_DESCRIPTION("SiS964 SMBus driver");
-- 
1.7.8.6

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