1 files changed, 554 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-iop3xx.c b/drivers/i2c/busses/i2c-iop3xx.c
new file mode 100644
index 000000000000..c961ba4cfb32
--- /dev/null
+++ b/drivers/i2c/busses/i2c-iop3xx.c
@@ -0,0 +1,554 @@
+/* ------------------------------------------------------------------------- */
+/* i2c-iop3xx.c i2c driver algorithms for Intel XScale IOP3xx & IXP46x       */
+/* ------------------------------------------------------------------------- */
+/* Copyright (C) 2003 Peter Milne, D-TACQ Solutions Ltd
+ *                    <Peter dot Milne at D hyphen TACQ dot com>
+ *
+ * With acknowledgements to i2c-algo-ibm_ocp.c by 
+ * Ian DaSilva, MontaVista Software, Inc. idasilva@mvista.com
+ *
+ * And i2c-algo-pcf.c, which was created by Simon G. Vogl and Hans Berglund:
+ *
+ * Copyright (C) 1995-1997 Simon G. Vogl, 1998-2000 Hans Berglund
+ *  
+ * And which acknowledged Kyösti Mälkki <kmalkki@cc.hut.fi>,
+ * Frodo Looijaard <frodol@dds.nl>, Martin Bailey<mbailey@littlefeet-inc.com>
+ *
+ * Major cleanup by Deepak Saxena <dsaxena@plexity.net>, 01/2005:
+ *
+ * - Use driver model to pass per-chip info instead of hardcoding and #ifdefs
+ * - Use ioremap/__raw_readl/__raw_writel instead of direct dereference
+ * - Make it work with IXP46x chips
+ * - Cleanup function names, coding style, etc
+ *
+ * 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, version 2.
+ */
+
+#include <linux/config.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+
+#include <asm/io.h>
+
+#include "i2c-iop3xx.h"
+
+/* global unit counter */
+static int i2c_id = 0;
+
+static inline unsigned char 
+iic_cook_addr(struct i2c_msg *msg) 
+{
+        unsigned char addr;
+
+        addr = (msg->addr << 1);
+
+        if (msg->flags & I2C_M_RD)
+                addr |= 1;
+
+        /*
+         * Read or Write?
+         */
+        if (msg->flags & I2C_M_REV_DIR_ADDR)
+                addr ^= 1;
+
+        return addr;   
+}
+
+static void 
+iop3xx_i2c_reset(struct i2c_algo_iop3xx_data *iop3xx_adap)
+{
+        /* Follows devman 9.3 */
+        __raw_writel(IOP3XX_ICR_UNIT_RESET, iop3xx_adap->ioaddr + CR_OFFSET);
+        __raw_writel(IOP3XX_ISR_CLEARBITS, iop3xx_adap->ioaddr + SR_OFFSET);
+        __raw_writel(0, iop3xx_adap->ioaddr + CR_OFFSET);
+} 
+
+static void 
+iop3xx_i2c_set_slave_addr(struct i2c_algo_iop3xx_data *iop3xx_adap)
+{
+        __raw_writel(MYSAR, iop3xx_adap->ioaddr + SAR_OFFSET);
+}
+
+static void 
+iop3xx_i2c_enable(struct i2c_algo_iop3xx_data *iop3xx_adap)
+{
+        u32 cr = IOP3XX_ICR_GCD | IOP3XX_ICR_SCLEN | IOP3XX_ICR_UE;
+
+        /* 
+         * Everytime unit enable is asserted, GPOD needs to be cleared
+         * on IOP321 to avoid data corruption on the bus.
+         */
+#ifdef CONFIG_ARCH_IOP321
+#define IOP321_GPOD_I2C0    0x00c0  /* clear these bits to enable ch0 */
+#define IOP321_GPOD_I2C1    0x0030  /* clear these bits to enable ch1 */
+
+        *IOP321_GPOD &= (iop3xx_adap->id == 0) ? ~IOP321_GPOD_I2C0 : 
+                ~IOP321_GPOD_I2C1;
+#endif
+        /* NB SR bits not same position as CR IE bits :-( */
+        iop3xx_adap->SR_enabled = 
+                IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD |
+                IOP3XX_ISR_RXFULL | IOP3XX_ISR_TXEMPTY;
+
+        cr |= IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE |
+                IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE;
+
+        __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
+}
+
+static void 
+iop3xx_i2c_transaction_cleanup(struct i2c_algo_iop3xx_data *iop3xx_adap)
+{
+        unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
+        
+        cr &= ~(IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE | 
+                IOP3XX_ICR_MSTOP | IOP3XX_ICR_SCLEN);
+
+        __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
+}
+
+/* 
+ * NB: the handler has to clear the source of the interrupt! 
+ * Then it passes the SR flags of interest to BH via adap data
+ */
+static irqreturn_t 
+iop3xx_i2c_irq_handler(int this_irq, void *dev_id, struct pt_regs *regs) 
+{
+        struct i2c_algo_iop3xx_data *iop3xx_adap = dev_id;
+        u32 sr = __raw_readl(iop3xx_adap->ioaddr + SR_OFFSET);
+
+        if ((sr &= iop3xx_adap->SR_enabled)) {
+                __raw_writel(sr, iop3xx_adap->ioaddr + SR_OFFSET);
+                iop3xx_adap->SR_received |= sr;
+                wake_up_interruptible(&iop3xx_adap->waitq);
+        }
+        return IRQ_HANDLED;
+}
+
+/* check all error conditions, clear them , report most important */
+static int 
+iop3xx_i2c_error(u32 sr)
+{
+        int rc = 0;
+
+        if ((sr & IOP3XX_ISR_BERRD)) {
+                if ( !rc ) rc = -I2C_ERR_BERR;
+        }
+        if ((sr & IOP3XX_ISR_ALD)) {
+                if ( !rc ) rc = -I2C_ERR_ALD;           
+        }
+        return rc;      
+}
+
+static inline u32 
+iop3xx_i2c_get_srstat(struct i2c_algo_iop3xx_data *iop3xx_adap)
+{
+        unsigned long flags;
+        u32 sr;
+
+        spin_lock_irqsave(&iop3xx_adap->lock, flags);
+        sr = iop3xx_adap->SR_received;
+        iop3xx_adap->SR_received = 0;
+        spin_unlock_irqrestore(&iop3xx_adap->lock, flags);
+
+        return sr;
+}
+
+/*
+ * sleep until interrupted, then recover and analyse the SR
+ * saved by handler
+ */
+typedef int (* compare_func)(unsigned test, unsigned mask);
+/* returns 1 on correct comparison */
+
+static int 
+iop3xx_i2c_wait_event(struct i2c_algo_iop3xx_data *iop3xx_adap, 
+                          unsigned flags, unsigned* status,
+                          compare_func compare)
+{
+        unsigned sr = 0;
+        int interrupted;
+        int done;
+        int rc = 0;
+
+        do {
+                interrupted = wait_event_interruptible_timeout (
+                        iop3xx_adap->waitq,
+                        (done = compare( sr = iop3xx_i2c_get_srstat(iop3xx_adap)                                        ,flags )),
+                        1 * HZ;
+                        );
+                if ((rc = iop3xx_i2c_error(sr)) < 0) {
+                        *status = sr;
+                        return rc;
+                } else if (!interrupted) {
+                        *status = sr;
+                        return -ETIMEDOUT;
+                }
+        } while(!done);
+
+        *status = sr;
+
+        return 0;
+}
+
+/*
+ * Concrete compare_funcs 
+ */
+static int 
+all_bits_clear(unsigned test, unsigned mask)
+{
+        return (test & mask) == 0;
+}
+
+static int 
+any_bits_set(unsigned test, unsigned mask)
+{
+        return (test & mask) != 0;
+}
+
+static int 
+iop3xx_i2c_wait_tx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
+{
+        return iop3xx_i2c_wait_event( 
+                iop3xx_adap, 
+                IOP3XX_ISR_TXEMPTY | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD,
+                status, any_bits_set);
+}
+
+static int 
+iop3xx_i2c_wait_rx_done(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
+{
+        return iop3xx_i2c_wait_event( 
+                iop3xx_adap, 
+                IOP3XX_ISR_RXFULL | IOP3XX_ISR_ALD | IOP3XX_ISR_BERRD,
+                status, any_bits_set);
+}
+
+static int 
+iop3xx_i2c_wait_idle(struct i2c_algo_iop3xx_data *iop3xx_adap, int *status)
+{
+        return iop3xx_i2c_wait_event( 
+                iop3xx_adap, IOP3XX_ISR_UNITBUSY, status, all_bits_clear);
+}
+
+static int 
+iop3xx_i2c_send_target_addr(struct i2c_algo_iop3xx_data *iop3xx_adap, 
+                                struct i2c_msg* msg)
+{
+        unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
+        int status;
+        int rc;
+
+        __raw_writel(iic_cook_addr(msg), iop3xx_adap->ioaddr + DBR_OFFSET);
+        
+        cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK);
+        cr |= IOP3XX_ICR_MSTART | IOP3XX_ICR_TBYTE;
+
+        __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
+        rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status);
+
+        return rc;
+}
+
+static int 
+iop3xx_i2c_write_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char byte, 
+                                int stop)
+{
+        unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
+        int status;
+        int rc = 0;
+
+        __raw_writel(byte, iop3xx_adap->ioaddr + DBR_OFFSET);
+        cr &= ~IOP3XX_ICR_MSTART;
+        if (stop) {
+                cr |= IOP3XX_ICR_MSTOP;
+        } else {
+                cr &= ~IOP3XX_ICR_MSTOP;
+        }
+        cr |= IOP3XX_ICR_TBYTE;
+        __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
+        rc = iop3xx_i2c_wait_tx_done(iop3xx_adap, &status);
+
+        return rc;
+} 
+
+static int 
+iop3xx_i2c_read_byte(struct i2c_algo_iop3xx_data *iop3xx_adap, char* byte, 
+                                int stop)
+{
+        unsigned long cr = __raw_readl(iop3xx_adap->ioaddr + CR_OFFSET);
+        int status;
+        int rc = 0;
+
+        cr &= ~IOP3XX_ICR_MSTART;
+
+        if (stop) {
+                cr |= IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK;
+        } else {
+                cr &= ~(IOP3XX_ICR_MSTOP | IOP3XX_ICR_NACK);
+        }
+        cr |= IOP3XX_ICR_TBYTE;
+        __raw_writel(cr, iop3xx_adap->ioaddr + CR_OFFSET);
+
+        rc = iop3xx_i2c_wait_rx_done(iop3xx_adap, &status);
+
+        *byte = __raw_readl(iop3xx_adap->ioaddr + DBR_OFFSET);
+
+        return rc;
+}
+
+static int 
+iop3xx_i2c_writebytes(struct i2c_adapter *i2c_adap, const char *buf, int count)
+{
+        struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
+        int ii;
+        int rc = 0;
+
+        for (ii = 0; rc == 0 && ii != count; ++ii) 
+                rc = iop3xx_i2c_write_byte(iop3xx_adap, buf[ii], ii==count-1);
+        return rc;
+}
+
+static int 
+iop3xx_i2c_readbytes(struct i2c_adapter *i2c_adap, char *buf, int count)
+{
+        struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
+        int ii;
+        int rc = 0;
+
+        for (ii = 0; rc == 0 && ii != count; ++ii)
+                rc = iop3xx_i2c_read_byte(iop3xx_adap, &buf[ii], ii==count-1);
+        
+        return rc;
+}
+
+/*
+ * Description:  This function implements combined transactions.  Combined
+ * transactions consist of combinations of reading and writing blocks of data.
+ * FROM THE SAME ADDRESS
+ * Each transfer (i.e. a read or a write) is separated by a repeated start
+ * condition.
+ */
+static int 
+iop3xx_i2c_handle_msg(struct i2c_adapter *i2c_adap, struct i2c_msg* pmsg) 
+{
+        struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
+        int rc;
+
+        rc = iop3xx_i2c_send_target_addr(iop3xx_adap, pmsg);
+        if (rc < 0) {
+                return rc;
+        }
+
+        if ((pmsg->flags&I2C_M_RD)) {
+                return iop3xx_i2c_readbytes(i2c_adap, pmsg->buf, pmsg->len);
+        } else {
+                return iop3xx_i2c_writebytes(i2c_adap, pmsg->buf, pmsg->len);
+        }
+}
+
+/*
+ * master_xfer() - main read/write entry
+ */
+static int 
+iop3xx_i2c_master_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, 
+                                int num)
+{
+        struct i2c_algo_iop3xx_data *iop3xx_adap = i2c_adap->algo_data;
+        int im = 0;
+        int ret = 0;
+        int status;
+
+        iop3xx_i2c_wait_idle(iop3xx_adap, &status);
+        iop3xx_i2c_reset(iop3xx_adap);
+        iop3xx_i2c_enable(iop3xx_adap);
+
+        for (im = 0; ret == 0 && im != num; im++) {
+                ret = iop3xx_i2c_handle_msg(i2c_adap, &msgs[im]);
+        }
+
+        iop3xx_i2c_transaction_cleanup(iop3xx_adap);
+        
+        if(ret)
+                return ret;
+
+        return im;   
+}
+
+static int 
+iop3xx_i2c_algo_control(struct i2c_adapter *adapter, unsigned int cmd,
+                        unsigned long arg)
+{
+        return 0;
+}
+
+static u32 
+iop3xx_i2c_func(struct i2c_adapter *adap)
+{
+        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm iop3xx_i2c_algo = {
+        .name           = "IOP3xx I2C algorithm",
+        .id             = I2C_ALGO_IOP3XX,
+        .master_xfer    = iop3xx_i2c_master_xfer,
+        .algo_control   = iop3xx_i2c_algo_control,
+        .functionality  = iop3xx_i2c_func,
+};
+
+static int 
+iop3xx_i2c_remove(struct device *device)
+{
+        struct platform_device *pdev = to_platform_device(device);
+        struct i2c_adapter *padapter = dev_get_drvdata(&pdev->dev);
+        struct i2c_algo_iop3xx_data *adapter_data = 
+                (struct i2c_algo_iop3xx_data *)padapter->algo_data;
+        struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        unsigned long cr = __raw_readl(adapter_data->ioaddr + CR_OFFSET);
+
+        /*
+         * Disable the actual HW unit
+         */
+        cr &= ~(IOP3XX_ICR_ALD_IE | IOP3XX_ICR_BERR_IE |
+                IOP3XX_ICR_RXFULL_IE | IOP3XX_ICR_TXEMPTY_IE);
+        __raw_writel(cr, adapter_data->ioaddr + CR_OFFSET);
+
+        iounmap((void __iomem*)adapter_data->ioaddr);
+        release_mem_region(res->start, IOP3XX_I2C_IO_SIZE);
+        kfree(adapter_data);
+        kfree(padapter);
+
+        dev_set_drvdata(&pdev->dev, NULL);
+
+        return 0;
+}
+
+static int 
+iop3xx_i2c_probe(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct resource *res;
+        int ret;
+        struct i2c_adapter *new_adapter;
+        struct i2c_algo_iop3xx_data *adapter_data;
+
+        new_adapter = kmalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
+        if (!new_adapter) {
+                ret = -ENOMEM;
+                goto out;
+        }
+        memset((void*)new_adapter, 0, sizeof(*new_adapter));
+
+        adapter_data = kmalloc(sizeof(struct i2c_algo_iop3xx_data), GFP_KERNEL);
+        if (!adapter_data) {
+                ret = -ENOMEM;
+                goto free_adapter;
+        }
+        memset((void*)adapter_data, 0, sizeof(*adapter_data));
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res) {
+                ret = -ENODEV;
+                goto free_both;
+        }
+
+        if (!request_mem_region(res->start, IOP3XX_I2C_IO_SIZE, pdev->name)) {
+                ret = -EBUSY;
+                goto free_both;
+        }
+
+        /* set the adapter enumeration # */
+        adapter_data->id = i2c_id++;
+
+        adapter_data->ioaddr = (u32)ioremap(res->start, IOP3XX_I2C_IO_SIZE);
+        if (!adapter_data->ioaddr) {
+                ret = -ENOMEM;
+                goto release_region;
+        }
+
+        res = request_irq(platform_get_irq(pdev, 0), iop3xx_i2c_irq_handler, 0, 
+                                pdev->name, adapter_data);
+        if (res) {
+                ret = -EIO;
+                goto unmap;
+        }
+
+        memcpy(new_adapter->name, pdev->name, strlen(pdev->name));
+        new_adapter->id = I2C_HW_IOP3XX;
+        new_adapter->owner = THIS_MODULE;
+        new_adapter->dev.parent = &pdev->dev;
+
+        /*
+         * Default values...should these come in from board code?
+         */
+        new_adapter->timeout = 100;     
+        new_adapter->retries = 3;
+        new_adapter->algo = &iop3xx_i2c_algo;
+
+        init_waitqueue_head(&adapter_data->waitq);
+        spin_lock_init(&adapter_data->lock);
+
+        iop3xx_i2c_reset(adapter_data);
+        iop3xx_i2c_set_slave_addr(adapter_data);
+        iop3xx_i2c_enable(adapter_data);
+
+        dev_set_drvdata(&pdev->dev, new_adapter);
+        new_adapter->algo_data = adapter_data;
+
+        i2c_add_adapter(new_adapter);
+
+        return 0;
+
+unmap:
+        iounmap((void __iomem*)adapter_data->ioaddr);
+
+release_region:
+        release_mem_region(res->start, IOP3XX_I2C_IO_SIZE);
+
+free_both:
+        kfree(adapter_data);
+
+free_adapter:
+        kfree(new_adapter);
+
+out:
+        return ret;
+}
+
+
+static struct device_driver iop3xx_i2c_driver = {
+        .name           = "IOP3xx-I2C",
+        .bus            = &platform_bus_type,
+        .probe          = iop3xx_i2c_probe,
+        .remove         = iop3xx_i2c_remove
+};
+
+static int __init 
+i2c_iop3xx_init (void)
+{
+        return driver_register(&iop3xx_i2c_driver);
+}
+
+static void __exit 
+i2c_iop3xx_exit (void)
+{
+        driver_unregister(&iop3xx_i2c_driver);
+        return;
+}
+
+module_init (i2c_iop3xx_init);
+module_exit (i2c_iop3xx_exit);
+
+MODULE_AUTHOR("D-TACQ Solutions Ltd <www.d-tacq.com>");
+MODULE_DESCRIPTION("IOP3xx iic algorithm and driver");
+MODULE_LICENSE("GPL");