i2c: PA Semi SMBus driver

New driver for the PA Semi SMBus interfaces.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

4 files changed, 440 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index f85c603b02a3..93a338daedd8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2523,6 +2523,12 @@ M:	olof@lixom.net
 L:      netdev@vger.kernel.org
 S:      Maintained
 
+PA SEMI SMBUS DRIVER
+P:      Olof Johansson
+M:      olof@lixom.net
+L:      i2c@lm-sensors.org
+S:      Maintained
+
 PARALLEL PORT SUPPORT
 P:      Phil Blundell
 M:      philb@gnu.org
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 25d52e0eec2c..4d44a2db29dd 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -342,6 +342,13 @@ config I2C_PARPORT_LIGHT
           This support is also available as a module.  If so, the module 
           will be called i2c-parport-light.
 
+config I2C_PASEMI
+        tristate "PA Semi SMBus interface"
+#       depends on PPC_PASEMI && I2C && PCI
+        depends on I2C && PCI
+        help
+          Supports the PA Semi PWRficient on-chip SMBus interfaces.
+
 config I2C_PROSAVAGE
         tristate "S3/VIA (Pro)Savage"
         depends on I2C && PCI
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 37196c1d0794..03505aa44bbf 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_I2C_OCORES)	+= i2c-ocores.o
 obj-$(CONFIG_I2C_OMAP)          += i2c-omap.o
 obj-$(CONFIG_I2C_PARPORT)       += i2c-parport.o
 obj-$(CONFIG_I2C_PARPORT_LIGHT) += i2c-parport-light.o
+obj-$(CONFIG_I2C_PASEMI)        += i2c-pasemi.o
 obj-$(CONFIG_I2C_PCA_ISA)       += i2c-pca-isa.o
 obj-$(CONFIG_I2C_PIIX4)         += i2c-piix4.o
 obj-$(CONFIG_I2C_PNX)           += i2c-pnx.o
diff --git a/drivers/i2c/busses/i2c-pasemi.c b/drivers/i2c/busses/i2c-pasemi.c
new file mode 100644
index 000000000000..f54fb5d65cc4
--- /dev/null
+++ b/drivers/i2c/busses/i2c-pasemi.c
@@ -0,0 +1,426 @@
+/*
+ * Copyright (C) 2006-2007 PA Semi, Inc
+ *
+ * SMBus host driver for PA Semi PWRficient
+ *
+ * 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.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/stddef.h>
+#include <linux/sched.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <asm/io.h>
+
+static struct pci_driver pasemi_smb_driver;
+
+struct pasemi_smbus {
+        struct pci_dev          *dev;
+        struct i2c_adapter       adapter;
+        unsigned long            base;
+        int                      size;
+};
+
+/* Register offsets */
+#define REG_MTXFIFO     0x00
+#define REG_MRXFIFO     0x04
+#define REG_SMSTA       0x14
+#define REG_CTL         0x1c
+
+/* Register defs */
+#define MTXFIFO_READ    0x00000400
+#define MTXFIFO_STOP    0x00000200
+#define MTXFIFO_START   0x00000100
+#define MTXFIFO_DATA_M  0x000000ff
+
+#define MRXFIFO_EMPTY   0x00000100
+#define MRXFIFO_DATA_M  0x000000ff
+
+#define SMSTA_XEN       0x08000000
+
+#define CTL_MRR         0x00000400
+#define CTL_MTR         0x00000200
+#define CTL_CLK_M       0x000000ff
+
+#define CLK_100K_DIV    84
+#define CLK_400K_DIV    21
+
+static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
+{
+        dev_dbg(&smbus->dev->dev, "smbus write reg %lx val %08x\n",
+                smbus->base + reg, val);
+        outl(val, smbus->base + reg);
+}
+
+static inline int reg_read(struct pasemi_smbus *smbus, int reg)
+{
+        int ret;
+        ret = inl(smbus->base + reg);
+        dev_dbg(&smbus->dev->dev, "smbus read reg %lx val %08x\n",
+                smbus->base + reg, ret);
+        return ret;
+}
+
+#define TXFIFO_WR(smbus, reg)   reg_write((smbus), REG_MTXFIFO, (reg))
+#define RXFIFO_RD(smbus)        reg_read((smbus), REG_MRXFIFO)
+
+static void pasemi_smb_clear(struct pasemi_smbus *smbus)
+{
+        unsigned int status;
+
+        status = reg_read(smbus, REG_SMSTA);
+        reg_write(smbus, REG_SMSTA, status);
+}
+
+static unsigned int pasemi_smb_waitready(struct pasemi_smbus *smbus)
+{
+        int timeout = 10;
+        unsigned int status;
+
+        status = reg_read(smbus, REG_SMSTA);
+
+        while (!(status & SMSTA_XEN) && timeout--) {
+                msleep(1);
+                status = reg_read(smbus, REG_SMSTA);
+        }
+
+        if (timeout < 0) {
+                dev_warn(&smbus->dev->dev, "Timeout, status 0x%08x\n", status);
+                reg_write(smbus, REG_SMSTA, status);
+                return -ETIME;
+        }
+
+        /* Clear XEN */
+        reg_write(smbus, REG_SMSTA, SMSTA_XEN);
+
+        return 0;
+}
+
+static int pasemi_i2c_xfer_msg(struct i2c_adapter *adapter,
+                               struct i2c_msg *msg, int stop)
+{
+        struct pasemi_smbus *smbus = adapter->algo_data;
+        int read, i, err;
+        u32 rd;
+
+        read = msg->flags & I2C_M_RD ? 1 : 0;
+
+        TXFIFO_WR(smbus, MTXFIFO_START | (msg->addr << 1) | read);
+
+        if (read) {
+                TXFIFO_WR(smbus, msg->len | MTXFIFO_READ |
+                                 (stop ? MTXFIFO_STOP : 0));
+
+                err = pasemi_smb_waitready(smbus);
+                if (err)
+                        goto reset_out;
+
+                for (i = 0; i < msg->len; i++) {
+                        rd = RXFIFO_RD(smbus);
+                        if (rd & MRXFIFO_EMPTY) {
+                                err = -ENODATA;
+                                goto reset_out;
+                        }
+                        msg->buf[i] = rd & MRXFIFO_DATA_M;
+                }
+        } else {
+                for (i = 0; i < msg->len - 1; i++)
+                        TXFIFO_WR(smbus, msg->buf[i]);
+
+                TXFIFO_WR(smbus, msg->buf[msg->len] |
+                          (stop ? MTXFIFO_STOP : 0));
+        }
+
+        return 0;
+
+ reset_out:
+        reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
+                  (CLK_100K_DIV & CTL_CLK_M)));
+        return err;
+}
+
+static int pasemi_i2c_xfer(struct i2c_adapter *adapter,
+                           struct i2c_msg *msgs, int num)
+{
+        struct pasemi_smbus *smbus = adapter->algo_data;
+        int ret, i;
+
+        pasemi_smb_clear(smbus);
+
+        ret = 0;
+
+        for (i = 0; i < num && !ret; i++)
+                ret = pasemi_i2c_xfer_msg(adapter, &msgs[i], (i == (num - 1)));
+
+        return ret ? ret : num;
+}
+
+static int pasemi_smb_xfer(struct i2c_adapter *adapter,
+                u16 addr, unsigned short flags, char read_write, u8 command,
+                int size, union i2c_smbus_data *data)
+{
+        struct pasemi_smbus *smbus = adapter->algo_data;
+        unsigned int rd;
+        int read_flag, err;
+        int len = 0, i;
+
+        /* All our ops take 8-bit shifted addresses */
+        addr <<= 1;
+        read_flag = read_write == I2C_SMBUS_READ;
+
+        pasemi_smb_clear(smbus);
+
+        switch (size) {
+        case I2C_SMBUS_QUICK:
+                TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START |
+                          MTXFIFO_STOP);
+                break;
+        case I2C_SMBUS_BYTE:
+                TXFIFO_WR(smbus, addr | read_flag | MTXFIFO_START);
+                if (read_write)
+                        TXFIFO_WR(smbus, 1 | MTXFIFO_STOP | MTXFIFO_READ);
+                else
+                        TXFIFO_WR(smbus, MTXFIFO_STOP | command);
+                break;
+        case I2C_SMBUS_BYTE_DATA:
+                TXFIFO_WR(smbus, addr | MTXFIFO_START);
+                TXFIFO_WR(smbus, command);
+                if (read_write) {
+                        TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
+                        TXFIFO_WR(smbus, 1 | MTXFIFO_READ | MTXFIFO_STOP);
+                } else {
+                        TXFIFO_WR(smbus, MTXFIFO_STOP | data->byte);
+                }
+                break;
+        case I2C_SMBUS_WORD_DATA:
+                TXFIFO_WR(smbus, addr | MTXFIFO_START);
+                TXFIFO_WR(smbus, command);
+                if (read_write) {
+                        TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
+                        TXFIFO_WR(smbus, 2 | MTXFIFO_READ | MTXFIFO_STOP);
+                } else {
+                        TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M);
+                        TXFIFO_WR(smbus, MTXFIFO_STOP | (data->word >> 8));
+                }
+                break;
+        case I2C_SMBUS_BLOCK_DATA:
+                TXFIFO_WR(smbus, addr | MTXFIFO_START);
+                TXFIFO_WR(smbus, command);
+                if (read_write) {
+                        TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
+                        TXFIFO_WR(smbus, 1 | MTXFIFO_READ);
+                        rd = RXFIFO_RD(smbus);
+                        len = min_t(u8, (rd & MRXFIFO_DATA_M),
+                                    I2C_SMBUS_BLOCK_MAX);
+                        TXFIFO_WR(smbus, (len + 1) | MTXFIFO_READ |
+                                         MTXFIFO_STOP);
+                } else {
+                        len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX);
+                        TXFIFO_WR(smbus, len);
+                        for (i = 1; i < len; i++)
+                                TXFIFO_WR(smbus, data->block[i]);
+                        TXFIFO_WR(smbus, data->block[len] | MTXFIFO_STOP);
+                }
+                break;
+        case I2C_SMBUS_PROC_CALL:
+                read_write = I2C_SMBUS_READ;
+                TXFIFO_WR(smbus, addr | MTXFIFO_START);
+                TXFIFO_WR(smbus, command);
+                TXFIFO_WR(smbus, data->word & MTXFIFO_DATA_M);
+                TXFIFO_WR(smbus, (data->word >> 8) & MTXFIFO_DATA_M);
+                TXFIFO_WR(smbus, addr | I2C_SMBUS_READ | MTXFIFO_START);
+                TXFIFO_WR(smbus, 2 | MTXFIFO_STOP | MTXFIFO_READ);
+                break;
+        case I2C_SMBUS_BLOCK_PROC_CALL:
+                len = min_t(u8, data->block[0], I2C_SMBUS_BLOCK_MAX - 1);
+                read_write = I2C_SMBUS_READ;
+                TXFIFO_WR(smbus, addr | MTXFIFO_START);
+                TXFIFO_WR(smbus, command);
+                TXFIFO_WR(smbus, len);
+                for (i = 1; i <= len; i++)
+                        TXFIFO_WR(smbus, data->block[i]);
+                TXFIFO_WR(smbus, addr | I2C_SMBUS_READ);
+                TXFIFO_WR(smbus, MTXFIFO_READ | 1);
+                rd = RXFIFO_RD(smbus);
+                len = min_t(u8, (rd & MRXFIFO_DATA_M),
+                            I2C_SMBUS_BLOCK_MAX - len);
+                TXFIFO_WR(smbus, (len + 1) | MTXFIFO_READ | MTXFIFO_STOP);
+                break;
+
+        default:
+                dev_warn(&adapter->dev, "Unsupported transaction %d\n", size);
+                return -EINVAL;
+        }
+
+        err = pasemi_smb_waitready(smbus);
+        if (err)
+                goto reset_out;
+
+        if (read_write == I2C_SMBUS_WRITE)
+                return 0;
+
+        switch (size) {
+        case I2C_SMBUS_BYTE:
+        case I2C_SMBUS_BYTE_DATA:
+                rd = RXFIFO_RD(smbus);
+                if (rd & MRXFIFO_EMPTY) {
+                        err = -ENODATA;
+                        goto reset_out;
+                }
+                data->byte = rd & MRXFIFO_DATA_M;
+                break;
+        case I2C_SMBUS_WORD_DATA:
+        case I2C_SMBUS_PROC_CALL:
+                rd = RXFIFO_RD(smbus);
+                if (rd & MRXFIFO_EMPTY) {
+                        err = -ENODATA;
+                        goto reset_out;
+                }
+                data->word = rd & MRXFIFO_DATA_M;
+                rd = RXFIFO_RD(smbus);
+                if (rd & MRXFIFO_EMPTY) {
+                        err = -ENODATA;
+                        goto reset_out;
+                }
+                data->word |= (rd & MRXFIFO_DATA_M) << 8;
+                break;
+        case I2C_SMBUS_BLOCK_DATA:
+        case I2C_SMBUS_BLOCK_PROC_CALL:
+                data->block[0] = len;
+                for (i = 1; i <= len; i ++) {
+                        rd = RXFIFO_RD(smbus);
+                        if (rd & MRXFIFO_EMPTY) {
+                                err = -ENODATA;
+                                goto reset_out;
+                        }
+                        data->block[i] = rd & MRXFIFO_DATA_M;
+                }
+                break;
+        }
+
+        return 0;
+
+ reset_out:
+        reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
+                  (CLK_100K_DIV & CTL_CLK_M)));
+        return err;
+}
+
+static u32 pasemi_smb_func(struct i2c_adapter *adapter)
+{
+        return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+               I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+               I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_SMBUS_PROC_CALL |
+               I2C_FUNC_SMBUS_BLOCK_PROC_CALL | I2C_FUNC_I2C;
+}
+
+static const struct i2c_algorithm smbus_algorithm = {
+        .master_xfer    = pasemi_i2c_xfer,
+        .smbus_xfer     = pasemi_smb_xfer,
+        .functionality  = pasemi_smb_func,
+};
+
+static int __devinit pasemi_smb_probe(struct pci_dev *dev,
+                                      const struct pci_device_id *id)
+{
+        struct pasemi_smbus *smbus;
+        int error;
+
+        if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
+                return -ENODEV;
+
+        smbus = kzalloc(sizeof(struct pasemi_smbus), GFP_KERNEL);
+        if (!smbus)
+                return -ENOMEM;
+
+        smbus->dev = dev;
+        smbus->base = pci_resource_start(dev, 0);
+        smbus->size = pci_resource_len(dev, 0);
+
+        if (!request_region(smbus->base, smbus->size,
+                            pasemi_smb_driver.name)) {
+                error = -EBUSY;
+                goto out_kfree;
+        }
+
+        smbus->adapter.owner = THIS_MODULE;
+        snprintf(smbus->adapter.name, I2C_NAME_SIZE,
+                 "PA Semi SMBus adapter at 0x%lx", smbus->base);
+        smbus->adapter.class = I2C_CLASS_HWMON;
+        smbus->adapter.algo = &smbus_algorithm;
+        smbus->adapter.algo_data = smbus;
+
+        /* set up the driverfs linkage to our parent device */
+        smbus->adapter.dev.parent = &dev->dev;
+
+        reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
+                  (CLK_100K_DIV & CTL_CLK_M)));
+
+        error = i2c_add_adapter(&smbus->adapter);
+        if (error)
+                goto out_release_region;
+
+        pci_set_drvdata(dev, smbus);
+
+        return 0;
+
+ out_release_region:
+        release_region(smbus->base, smbus->size);
+ out_kfree:
+        kfree(smbus);
+        return error;
+}
+
+static void __devexit pasemi_smb_remove(struct pci_dev *dev)
+{
+        struct pasemi_smbus *smbus = pci_get_drvdata(dev);
+
+        i2c_del_adapter(&smbus->adapter);
+        release_region(smbus->base, smbus->size);
+        kfree(smbus);
+}
+
+static struct pci_device_id pasemi_smb_ids[] = {
+        { PCI_DEVICE(0x1959, 0xa003) },
+        { 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, pasemi_smb_ids);
+
+static struct pci_driver pasemi_smb_driver = {
+        .name           = "i2c-pasemi",
+        .id_table       = pasemi_smb_ids,
+        .probe          = pasemi_smb_probe,
+        .remove         = __devexit_p(pasemi_smb_remove),
+};
+
+static int __init pasemi_smb_init(void)
+{
+        return pci_register_driver(&pasemi_smb_driver);
+}
+
+static void __exit pasemi_smb_exit(void)
+{
+        pci_unregister_driver(&pasemi_smb_driver);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR ("Olof Johansson <olof@lixom.net>");
+MODULE_DESCRIPTION("PA Semi PWRficient SMBus driver");
+
+module_init(pasemi_smb_init);
+module_exit(pasemi_smb_exit);