unicore32 machine related files: add i2c bus drivers for pkunity-v3 soc

change from original version -- by advice of Jean Delvare
1. remove global variable i2c_reg, replaced by local variables
2. replace ENXIO with ENODEV when no platform resources
3. add adapter->nr assignment before i2c_add_numbered_adapter() call
4. add judgement for i2c_del_adapter() return value
5. release adapter when driver removed
6. add __devexit for puv3_i2c_remove() function
7. modify several names to more appropriated ones

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>

3 files changed, 318 insertions, 0 deletions

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 113505a6434e..cbfcf6fb4a61 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -523,6 +523,17 @@ config I2C_PNX
           This driver can also be built as a module.  If so, the module
           will be called i2c-pnx.
 
+config I2C_PUV3
+        tristate "PKUnity v3 I2C bus support"
+        depends on UNICORE32 && ARCH_PUV3
+        select I2C_ALGOBIT
+        help
+          This driver supports the I2C IP inside the PKUnity-v3 SoC.
+          This I2C bus controller is under AMBA/AXI bus.
+
+          This driver can also be built as a module.  If so, the module
+          will be called i2c-puv3.
+
 config I2C_PXA
         tristate "Intel PXA2XX I2C adapter"
         depends on ARCH_PXA || ARCH_MMP
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 9d2d0ec7fb23..a83966acc5ab 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -51,6 +51,7 @@ obj-$(CONFIG_I2C_PASEMI)	+= i2c-pasemi.o
 obj-$(CONFIG_I2C_PCA_PLATFORM)  += i2c-pca-platform.o
 obj-$(CONFIG_I2C_PMCMSP)        += i2c-pmcmsp.o
 obj-$(CONFIG_I2C_PNX)           += i2c-pnx.o
+obj-$(CONFIG_I2C_PUV3)          += i2c-puv3.o
 obj-$(CONFIG_I2C_PXA)           += i2c-pxa.o
 obj-$(CONFIG_I2C_S3C2410)       += i2c-s3c2410.o
 obj-$(CONFIG_I2C_S6000)         += i2c-s6000.o
diff --git a/drivers/i2c/busses/i2c-puv3.c b/drivers/i2c/busses/i2c-puv3.c
new file mode 100644
index 000000000000..fac673940849
--- /dev/null
+++ b/drivers/i2c/busses/i2c-puv3.c
@@ -0,0 +1,306 @@
+/*
+ * I2C driver for PKUnity-v3 SoC
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ *      Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
+ *      Copyright (C) 2001-2010 Guan Xuetao
+ *
+ * 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/module.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <mach/hardware.h>
+
+/*
+ * Poll the i2c status register until the specified bit is set.
+ * Returns 0 if timed out (100 msec).
+ */
+static short poll_status(unsigned long bit)
+{
+        int loop_cntr = 1000;
+
+        if (bit & I2C_STATUS_TFNF) {
+                do {
+                        udelay(10);
+                } while (!(readl(I2C_STATUS) & bit) && (--loop_cntr > 0));
+        } else {
+                /* RXRDY handler */
+                do {
+                        if (readl(I2C_TAR) == I2C_TAR_EEPROM)
+                                msleep(20);
+                        else
+                                udelay(10);
+                } while (!(readl(I2C_RXFLR) & 0xf) && (--loop_cntr > 0));
+        }
+
+        return (loop_cntr > 0);
+}
+
+static int xfer_read(struct i2c_adapter *adap, unsigned char *buf, int length)
+{
+        int i2c_reg = *buf;
+
+        /* Read data */
+        while (length--) {
+                if (!poll_status(I2C_STATUS_TFNF)) {
+                        dev_dbg(&adap->dev, "Tx FIFO Not Full timeout\n");
+                        return -ETIMEDOUT;
+                }
+
+                /* send addr */
+                writel(i2c_reg | I2C_DATACMD_WRITE, I2C_DATACMD);
+
+                /* get ready to next write */
+                i2c_reg++;
+
+                /* send read CMD */
+                writel(I2C_DATACMD_READ, I2C_DATACMD);
+
+                /* wait until the Rx FIFO have available */
+                if (!poll_status(I2C_STATUS_RFNE)) {
+                        dev_dbg(&adap->dev, "RXRDY timeout\n");
+                        return -ETIMEDOUT;
+                }
+
+                /* read the data to buf */
+                *buf = (readl(I2C_DATACMD) & I2C_DATACMD_DAT_MASK);
+                buf++;
+        }
+
+        return 0;
+}
+
+static int xfer_write(struct i2c_adapter *adap, unsigned char *buf, int length)
+{
+        int i2c_reg = *buf;
+
+        /* Do nothing but storing the reg_num to a static variable */
+        if (i2c_reg == -1) {
+                printk(KERN_WARNING "Error i2c reg\n");
+                return -ETIMEDOUT;
+        }
+
+        if (length == 1)
+                return 0;
+
+        buf++;
+        length--;
+        while (length--) {
+                /* send addr */
+                writel(i2c_reg | I2C_DATACMD_WRITE, I2C_DATACMD);
+
+                /* send write CMD */
+                writel(*buf | I2C_DATACMD_WRITE, I2C_DATACMD);
+
+                /* wait until the Rx FIFO have available */
+                msleep(20);
+
+                /* read the data to buf */
+                i2c_reg++;
+                buf++;
+        }
+
+        return 0;
+}
+
+/*
+ * Generic i2c master transfer entrypoint.
+ *
+ */
+static int puv3_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *pmsg,
+                int num)
+{
+        int i, ret;
+        unsigned char swap;
+
+        /* Disable i2c */
+        writel(I2C_ENABLE_DISABLE, I2C_ENABLE);
+
+        /* Set the work mode and speed*/
+        writel(I2C_CON_MASTER | I2C_CON_SPEED_STD | I2C_CON_SLAVEDISABLE, I2C_CON);
+
+        writel(pmsg->addr, I2C_TAR);
+
+        /* Enable i2c */
+        writel(I2C_ENABLE_ENABLE, I2C_ENABLE);
+
+        dev_dbg(&adap->dev, "puv3_i2c_xfer: processing %d messages:\n", num);
+
+        for (i = 0; i < num; i++) {
+                dev_dbg(&adap->dev, " #%d: %sing %d byte%s %s 0x%02x\n", i,
+                        pmsg->flags & I2C_M_RD ? "read" : "writ",
+                        pmsg->len, pmsg->len > 1 ? "s" : "",
+                        pmsg->flags & I2C_M_RD ? "from" : "to", pmsg->addr);
+
+                if (pmsg->len && pmsg->buf) {   /* sanity check */
+                        if (pmsg->flags & I2C_M_RD)
+                                ret = xfer_read(adap, pmsg->buf, pmsg->len);
+                        else
+                                ret = xfer_write(adap, pmsg->buf, pmsg->len);
+
+                        if (ret)
+                                return ret;
+
+                }
+                dev_dbg(&adap->dev, "transfer complete\n");
+                pmsg++;         /* next message */
+        }
+
+        /* XXX: fixup be16_to_cpu in bq27x00_battery.c */
+        if (pmsg->addr == I2C_TAR_PWIC) {
+                swap = pmsg->buf[0];
+                pmsg->buf[0] = pmsg->buf[1];
+                pmsg->buf[1] = swap;
+        }
+
+        return i;
+}
+
+/*
+ * Return list of supported functionality.
+ */
+static u32 puv3_i2c_func(struct i2c_adapter *adapter)
+{
+        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm puv3_i2c_algorithm = {
+        .master_xfer    = puv3_i2c_xfer,
+        .functionality  = puv3_i2c_func,
+};
+
+/*
+ * Main initialization routine.
+ */
+static int __devinit puv3_i2c_probe(struct platform_device *pdev)
+{
+        struct i2c_adapter *adapter;
+        struct resource *mem;
+        int rc;
+
+        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!mem)
+                return -ENODEV;
+
+        if (!request_mem_region(mem->start, resource_size(mem), "puv3_i2c"))
+                return -EBUSY;
+
+        adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
+        if (adapter == NULL) {
+                dev_err(&pdev->dev, "can't allocate inteface!\n");
+                rc = -ENOMEM;
+                goto fail_nomem;
+        }
+        snprintf(adapter->name, sizeof(adapter->name), "PUV3-I2C at 0x%08x",
+                        mem->start);
+        adapter->algo = &puv3_i2c_algorithm;
+        adapter->class = I2C_CLASS_HWMON;
+        adapter->dev.parent = &pdev->dev;
+
+        platform_set_drvdata(pdev, adapter);
+
+        adapter->nr = pdev->id;
+        rc = i2c_add_numbered_adapter(adapter);
+        if (rc) {
+                dev_err(&pdev->dev, "Adapter '%s' registration failed\n",
+                                adapter->name);
+                goto fail_add_adapter;
+        }
+
+        dev_info(&pdev->dev, "PKUnity v3 i2c bus adapter.\n");
+        return 0;
+
+fail_add_adapter:
+        platform_set_drvdata(pdev, NULL);
+        kfree(adapter);
+fail_nomem:
+        release_mem_region(mem->start, resource_size(mem));
+
+        return rc;
+}
+
+static int __devexit puv3_i2c_remove(struct platform_device *pdev)
+{
+        struct i2c_adapter *adapter = platform_get_drvdata(pdev);
+        struct resource *mem;
+        int rc;
+
+        rc = i2c_del_adapter(adapter);
+        if (rc) {
+                dev_err(&pdev->dev, "Adapter '%s' delete fail\n",
+                                adapter->name);
+                return rc;
+        }
+
+        put_device(&pdev->dev);
+        platform_set_drvdata(pdev, NULL);
+
+        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        release_mem_region(mem->start, resource_size(mem));
+
+        return rc;
+}
+
+#ifdef CONFIG_PM
+static int puv3_i2c_suspend(struct platform_device *dev, pm_message_t state)
+{
+        int poll_count;
+        /* Disable the IIC */
+        writel(I2C_ENABLE_DISABLE, I2C_ENABLE);
+        for (poll_count = 0; poll_count < 50; poll_count++) {
+                if (readl(I2C_ENSTATUS) & I2C_ENSTATUS_ENABLE)
+                        udelay(25);
+        }
+
+        return 0;
+}
+
+static int puv3_i2c_resume(struct platform_device *dev)
+{
+        return 0 ;
+}
+#else
+#define puv3_i2c_suspend NULL
+#define puv3_i2c_resume NULL
+#endif
+
+MODULE_ALIAS("platform:puv3_i2c");
+
+static struct platform_driver puv3_i2c_driver = {
+        .probe          = puv3_i2c_probe,
+        .remove         = __devexit_p(puv3_i2c_remove),
+        .suspend        = puv3_i2c_suspend,
+        .resume         = puv3_i2c_resume,
+        .driver         = {
+                .name   = "PKUnity-v3-I2C",
+                .owner  = THIS_MODULE,
+        }
+};
+
+static int __init puv3_i2c_init(void)
+{
+        return platform_driver_register(&puv3_i2c_driver);
+}
+
+static void __exit puv3_i2c_exit(void)
+{
+        platform_driver_unregister(&puv3_i2c_driver);
+}
+
+module_init(puv3_i2c_init);
+module_exit(puv3_i2c_exit);
+
+MODULE_DESCRIPTION("PKUnity v3 I2C driver");
+MODULE_LICENSE("GPL v2");