On 28/08/13 15:04, [email protected] wrote:
From: Ian Molton<[email protected]>

There's nothing here. Please describe the contents of this patch.

Signed-off-by: Ian Molton<[email protected]>
---
  drivers/i2c/busses/Kconfig  |   10 +
  drivers/i2c/busses/Makefile |    1 +
  drivers/i2c/busses/i2c-em.c |  536 +++++++++++++++++++++++++++++++++++++++++++
  3 files changed, 547 insertions(+)
  create mode 100644 drivers/i2c/busses/i2c-em.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index dc6dea6..e5cda34 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -777,6 +777,16 @@ config I2C_RCAR
          This driver can also be built as a module.  If so, the module
          will be called i2c-rcar.

+config I2C_EM
+       tristate "EMMA Mobile series I2C adapter"
+       depends on I2C&&  HAVE_CLK
+       help
+         If you say yes to this option, support will be included for the
+         I2C interface on the Renesas Electronics EM/EV of processors.
+
+         This driver can also be built as a module.  If so, the module
+         will be called i2c-em
+
  comment "External I2C/SMBus adapter drivers"

  config I2C_DIOLAN_U2C
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index d00997f..f7022ab 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -76,6 +76,7 @@ obj-$(CONFIG_I2C_OCTEON)      += i2c-octeon.o
  obj-$(CONFIG_I2C_XILINX)      += i2c-xiic.o
  obj-$(CONFIG_I2C_XLR)         += i2c-xlr.o
  obj-$(CONFIG_I2C_RCAR)                += i2c-rcar.o
+obj-$(CONFIG_I2C_EM)            += i2c-em.o

  # External I2C/SMBus adapter drivers
  obj-$(CONFIG_I2C_DIOLAN_U2C)  += i2c-diolan-u2c.o
diff --git a/drivers/i2c/busses/i2c-em.c b/drivers/i2c/busses/i2c-em.c
new file mode 100644
index 0000000..b54a983
--- /dev/null
+++ b/drivers/i2c/busses/i2c-em.c
@@ -0,0 +1,536 @@
+/*
+ *  Release Date       : 2010/05/24
+ *
+ * (c) Ian Molton<[email protected]>

Copyright (c) Codethink Limited.
        Ian Molton <[email protected]>

+ * Parts (c) 2010 Renesas Electronics Corporation
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA.
+ */
+
+#include<linux/kernel.h>
+#include<linux/module.h>
+#include<linux/init.h>
+#include<linux/delay.h>
+#include<linux/of_i2c.h>
+#include<linux/clk.h>
+#include<linux/io.h>
+#include<linux/sched.h>
+
+#include<linux/interrupt.h>
+#include<linux/device.h>
+#include<linux/of_device.h>
+#include<linux/platform_device.h>
+
+/* INT Reg */
+#define EMXX_I2C_INT_RAW       (IO_ADDRESS(EMXX_INTA_D_BASE) + 0x014)
+#define EMXX_I2C_INT_IIR       (IO_ADDRESS(EMXX_INTA_D_BASE) + 0x024)
+
+/* INT Reg bit */
+#define EMXX_I2C0_INTC_MST     (1<<  0)
+#define EMXX_I2C1_INTC_MST     (1<<  1)
+#define EMXX_I2C0_INTC_IIR     (1<<  16)
+#define EMXX_I2C1_INTC_IIR     (1<<  17)

yuck, why do we have to prod other registers outside of the driver.

+/* I2C Registers */
+
+#define I2C_OFS_IICACT0                0x00    /* start */
+#define I2C_OFS_IIC0           0x04    /* shift */
+#define I2C_OFS_IICC0          0x08    /* control */
+#define I2C_OFS_SVA0           0x0c    /* slave address */
+#define I2C_OFS_IICCL0         0x10    /* clock select */
+#define I2C_OFS_IICX0          0x14    /* extention */
+#define I2C_OFS_IICS0          0x18    /* status */
+#define I2C_OFS_IICSE0         0x1c    /* status For emulation */
+#define I2C_OFS_IICF0          0x20    /* IIC flag */
+
+
+/* I2C IICACT0 Masks */
+#define I2C_BIT_IICE0          0x0001
+
+/* I2C IICC0 Masks */
+#define I2C_BIT_LREL0          0x0040
+#define I2C_BIT_WREL0          0x0020
+#define I2C_BIT_SPIE0          0x0010
+#define I2C_BIT_WTIM0          0x0008
+#define I2C_BIT_ACKE0          0x0004
+#define I2C_BIT_STT0           0x0002
+#define I2C_BIT_SPT0           0x0001
+
+/* I2C IICCL0 Masks */
+#define I2C_BIT_CLD0           0x0020
+#define I2C_BIT_DAD0           0x0010
+#define I2C_BIT_SMC0           0x0008
+#define I2C_BIT_DFC0           0x0004
+#define I2C_BIT_CLO1           0x0002
+#define I2C_BIT_CLO0           0x0001
+
+/* I2C IICSE0 Masks */
+#define I2C_BIT_MSTS0          0x0080
+#define I2C_BIT_ALD0           0x0040
+#define I2C_BIT_EXC0           0x0020
+#define I2C_BIT_COI0           0x0010
+#define I2C_BIT_TRC0           0x0008
+#define I2C_BIT_ACKD0          0x0004
+#define I2C_BIT_STD0           0x0002
+#define I2C_BIT_SPD0           0x0001
+
+/* I2C IICF0 Masks */
+#define I2C_BIT_STCF           0x0080
+#define I2C_BIT_IICBSY         0x0040
+#define I2C_BIT_STCEN          0x0002
+#define I2C_BIT_IICRSV         0x0001
+
+/* For setting of sending and receiving */
+#define I2C_DIR_R              0x01
+
+static int em_i2c_xfer(struct i2c_adapter *, struct i2c_msg[], int);
+
+struct em_i2c_device {
+       struct i2c_adapter      adap;
+       wait_queue_head_t       i2c_wait;
+       void __iomem            *membase;
+       struct clk              *clk;
+       struct clk              *sclk;
+       int                     irq;
+       int                     flags;
+       int                     pending;
+       spinlock_t              irq_lock;
+};
+
+static u32 em_i2c_func(struct i2c_adapter *adap)
+{
+       return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm em_i2c_algo = {
+       .master_xfer = em_i2c_xfer,
+       .smbus_xfer = NULL,
+       .functionality = em_i2c_func,
+};
+
+static void em_i2c_enable_clock(struct em_i2c_device *i2c_dev)
+{
+       clk_enable(i2c_dev->clk);
+       clk_enable(i2c_dev->sclk);
+}
+
+static void em_i2c_disable_clock(struct em_i2c_device *i2c_dev)
+{
+       clk_disable(i2c_dev->sclk);
+       clk_disable(i2c_dev->clk);
+}
+
+static int em_i2c_wait_for_event(struct em_i2c_device *i2c_dev, u16 *status)
+{
+       int interrupted;
+
+       do {
+               interrupted = wait_event_interruptible_timeout(
+                               i2c_dev->i2c_wait, i2c_dev->pending,
+                               i2c_dev->adap.timeout);
+
+               if (i2c_dev->pending) {
+                       spin_lock_irq(&i2c_dev->irq_lock);
+                       i2c_dev->pending = 0;
+                       spin_unlock_irq(&i2c_dev->irq_lock);
+                       *status = readl(i2c_dev->membase + I2C_OFS_IICSE0);
+                       return 0;
+               }
+
+       } while (interrupted);
+
+       *status = 0;
+
+       return -ETIMEDOUT;
+}
+
+static int em_i2c_stop(struct em_i2c_device *i2c_dev)
+{
+       u16 status;
+
+       /* Send Stop condition */
+       writel((readl(i2c_dev->membase + I2C_OFS_IICC0) | I2C_BIT_SPT0 |
+               I2C_BIT_SPIE0), i2c_dev->membase + I2C_OFS_IICC0);
+
+       /* Wait for stop condition */
+       em_i2c_wait_for_event(i2c_dev,&status);
+       /* FIXME - check status? */
+
+       if ((readl(i2c_dev->membase + I2C_OFS_IICSE0)&  I2C_BIT_SPD0) != 0)
+               return 0;
+
+       return -EBUSY;
+}
+
+static int em_i2c_start(struct em_i2c_device *i2c_dev)
+{
+       /* Send start condition */
+       writel((readl(i2c_dev->membase + I2C_OFS_IICC0)) | I2C_BIT_ACKE0 |
+               I2C_BIT_WTIM0, i2c_dev->membase + I2C_OFS_IICC0);
+
+       writel((readl(i2c_dev->membase + I2C_OFS_IICC0) | I2C_BIT_STT0),
+               i2c_dev->membase + I2C_OFS_IICC0);
+
+       return -EBUSY;
+}
+
+static void em_i2c_reset(struct i2c_adapter *adap)
+{
+       struct em_i2c_device *i2c_dev =
+               (struct em_i2c_device *)(i2c_get_adapdata(adap));
+
+       /* If I2C active */
+       if (readl(i2c_dev->membase + I2C_OFS_IICACT0)&  I2C_BIT_IICE0) {
+
+               /* Disable I2C operation */
+               writel(0, i2c_dev->membase + I2C_OFS_IICACT0);
+
+               while (readl(i2c_dev->membase + I2C_OFS_IICACT0) == 1)
+                       ;
+       }
+
+       /* Transfer mode set */
+       writel(i2c_dev->flags, i2c_dev->membase + I2C_OFS_IICCL0);
+
+       /* Can Issue start without detecting a stop, Reservation disabled. */
+       writel(I2C_BIT_STCEN | I2C_BIT_IICRSV,
+               i2c_dev->membase + I2C_OFS_IICF0);
+
+       /* I2C enable, 9 bit interrupt mode */
+       writel(I2C_BIT_WTIM0, i2c_dev->membase + I2C_OFS_IICC0);
+
+       /* Enable I2C operation */
+       writel(I2C_BIT_IICE0, i2c_dev->membase + I2C_OFS_IICACT0);
+
+       while (readl(i2c_dev->membase + I2C_OFS_IICACT0) == 0)
+               ;
+}
+
+static int __em_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
+                               int stop)
+{
+       struct em_i2c_device *i2c_dev =
+               (struct em_i2c_device *)i2c_get_adapdata(adap);
+       int count = 0;
+       u16 status;
+
+       /* Start transfer */
+       em_i2c_start(i2c_dev);
+
+       /* Send slave address and R/W type */
+       writel((msg->addr<<  1) | ((msg->flags&  I2C_M_RD) ? 1 : 0),
+               i2c_dev->membase + I2C_OFS_IIC0);
+
+       /* Wait for transaction */
+       if (em_i2c_wait_for_event(i2c_dev,&status))
+               goto out_reset;
+
+       /* Arbitration, Extension mode or Slave mode are all errors */
+       if (status&  (I2C_BIT_EXC0 | I2C_BIT_COI0 | I2C_BIT_ALD0)
+                       || !(status&  I2C_BIT_MSTS0))
+               goto out_reset;
+
+       /* Extra setup for read transactions */
+       if (!(status&  I2C_BIT_TRC0)) {
+
+               /* msg->flags is Write type */
+               if (!(msg->flags&  I2C_M_RD))
+                       goto out_reset;
+
+               /* Recieved No ACK (result of setting slave address and R/W) */
+               if (!(status&  I2C_BIT_ACKD0)) {
+                       em_i2c_stop(i2c_dev);
+                       goto out;
+               }
+
+               /* 8 bit interrupt mode */
+               writel((readl(i2c_dev->membase + I2C_OFS_IICC0)
+                               &  ~I2C_BIT_WTIM0) | I2C_BIT_ACKE0,
+                               i2c_dev->membase + I2C_OFS_IICC0);
+               writel((readl(i2c_dev->membase + I2C_OFS_IICC0)
+                               &  ~I2C_BIT_WTIM0) | I2C_BIT_WREL0,
+                               i2c_dev->membase + I2C_OFS_IICC0);
+
+               /* Wait for transaction */
+               if (em_i2c_wait_for_event(i2c_dev,&status))
+                       goto out_reset;
+       }
+
+       /* Send / receive data */
+       do {
+               /* Arbitration, Extension mode or Slave mode are errors*/
+               if (status&  (I2C_BIT_EXC0 | I2C_BIT_COI0 | I2C_BIT_ALD0)
+                               || !(status&  I2C_BIT_MSTS0))
+                       goto out_reset;
+
+               if (!(status&  I2C_BIT_TRC0)) { /* Read transaction */
+
+                       /* msg->flags is Write type */
+                       if (!(msg->flags&  I2C_M_RD))
+                               goto out_reset;
+
+                       if (count == msg->len)
+                               break;
+
+                       msg->buf[count++] =
+                               readl(i2c_dev->membase + I2C_OFS_IIC0);
+
+
+                       writel((readl(i2c_dev->membase + I2C_OFS_IICC0)
+                               | I2C_BIT_WREL0),
+                               i2c_dev->membase + I2C_OFS_IICC0);
+
+               } else { /* Write transaction */
+
+                       /* msg->flags is Read type */
+                       if ((msg->flags&  I2C_M_RD))
+                               goto out_reset;
+
+                       /* Recieved No ACK */
+                       if (!(status&  I2C_BIT_ACKD0)) {
+                               em_i2c_stop(i2c_dev);
+                               goto out;
+                       }
+
+                       if (count == msg->len)
+                               break;
+
+                       /* Write data */
+                       writel(msg->buf[count++], i2c_dev->membase
+                               + I2C_OFS_IIC0);
+               }
+
+               /* Wait for R/W transaction */
+               if (em_i2c_wait_for_event(i2c_dev,&status))
+                       goto out_reset;
+
+       } while (1);
+
+       if (stop)
+               em_i2c_stop(i2c_dev);
+
+       return count;
+
+out_reset:
+       em_i2c_reset(adap);
+out:
+       return -EREMOTEIO;
+}
+
+static int em_i2c_wait_free(struct i2c_adapter *adap)
+{
+       struct em_i2c_device *i2c_dev;
+       int status;
+       int timeout = adap->timeout;
+
+       i2c_dev = (struct em_i2c_device *)(i2c_get_adapdata(adap));
+
+       /* wait until I2C bus free */
+       while ((readl(i2c_dev->membase + I2C_OFS_IICF0)&  I2C_BIT_IICBSY)
+                       &&  timeout--) {
+               schedule_timeout_uninterruptible(1);
+       }
+
+       status = (timeout<= 0);
+
+       if (status)
+               dev_info(&adap->dev, "I2C bus is busy\n");
+
+       return status;
+}
+
+static int em_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+       int num)
+{
+       struct em_i2c_device *i2c_dev =
+               (struct em_i2c_device *)(i2c_get_adapdata(adap));
+       int ret = 0;
+       int i;
+
+       if (msgs == NULL)
+               return -EINVAL;
+
+       for (i = 0; i<  num; i++)
+               if (msgs[i].buf == NULL)
+                       return -EINVAL;
+
+       em_i2c_enable_clock(i2c_dev);
+       em_i2c_reset(adap);
+
+       /* Attempt to gain control of the adapter */
+       i = 0;
+       while (em_i2c_wait_free(adap)) {
+               switch (i) {
+               case 0:
+                       if (!(readl(i2c_dev->membase + I2C_OFS_IICSE0)
+                                       &  I2C_BIT_MSTS0)) {
+                               /* Slave mode ->  Error */
+                               ret = -EBUSY;
+                               goto out;
+                       }
+
+                       em_i2c_stop(i2c_dev);
+                       break;
+               case 1:
+                       em_i2c_reset(adap);
+                       break;
+               case 2:
+                       ret = -EREMOTEIO;
+                       goto out;
+               }
+               i++;
+       }
+
+       /* Send messages */
+       for (i = 0; i<  num; i++) {
+               ret = __em_i2c_xfer(adap,&msgs[i], (i == (num - 1)));
+               if (ret<  0)
+                       goto out;
+       }
+
+       /* I2C transfer completed */
+       ret = i;
+
+out:
+       em_i2c_disable_clock(i2c_dev);
+
+       return ret;
+}
+
+static irqreturn_t em_i2c_irq_handler(int this_irq, void *dev_id)
+{
+       struct em_i2c_device *i2c_dev = dev_id;
+
+       i2c_dev->pending = 1;
+
+       wake_up_interruptible(&i2c_dev->i2c_wait);
+
+       return IRQ_HANDLED;
+}
+
+static int em_i2c_probe(struct platform_device *pdev)
+{
+       struct em_i2c_device *i2c_dev;
+       struct resource *r;
+       int ret;
+
+       i2c_dev = devm_kzalloc(&pdev->dev, sizeof(struct em_i2c_device),
+                               GFP_KERNEL);
+
+       r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       i2c_dev->membase = devm_ioremap_resource(&pdev->dev, r);
+       if (IS_ERR(i2c_dev->membase))
+               return PTR_ERR(i2c_dev->membase);
+
+       strlcpy(i2c_dev->adap.name, "em_i2c", sizeof(i2c_dev->adap.name));
+
+       i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
+       if (!IS_ERR(i2c_dev->clk))
+               clk_prepare(i2c_dev->clk);
+
+       i2c_dev->sclk = devm_clk_get(&pdev->dev, "sclk");
+       if (!IS_ERR(i2c_dev->sclk))
+               clk_prepare(i2c_dev->sclk);
+
+       i2c_dev->irq = platform_get_irq(pdev, 0);
+       i2c_dev->adap.timeout = msecs_to_jiffies(100);
+       i2c_dev->adap.dev.parent =&pdev->dev;
+       i2c_dev->adap.algo =&em_i2c_algo;
+       i2c_dev->adap.owner = THIS_MODULE;
+       i2c_dev->adap.nr = pdev->id;
+       i2c_dev->adap.dev.of_node = pdev->dev.of_node;
+
+       init_waitqueue_head(&i2c_dev->i2c_wait);
+
+       spin_lock_init(&i2c_dev->irq_lock);
+
+       i2c_dev->flags = I2C_BIT_DFC0;
+#ifdef CONFIG_I2C_EMXX_SMC
+       i2c_dev->flags |= I2C_BIT_SMC0;
+#endif
+
+       platform_set_drvdata(pdev, i2c_dev);
+       i2c_set_adapdata(&i2c_dev->adap, i2c_dev);
+
+       em_i2c_enable_clock(i2c_dev);
+       em_i2c_reset(&i2c_dev->adap);
+       em_i2c_disable_clock(i2c_dev);
+
+       ret = devm_request_irq(&pdev->dev, i2c_dev->irq, em_i2c_irq_handler, 0,
+                               "em_i2c", i2c_dev);
+
+       if (ret)
+               goto exit_clk;
+
+       ret = i2c_add_numbered_adapter(&i2c_dev->adap);
+
+       if (ret != 0)
+               goto exit_clk;
+
+       of_i2c_register_devices(&i2c_dev->adap);
+
+       dev_info(&pdev->dev, "Added i2c controller %d irq %d @ 0x%p\n",
+               i2c_dev->adap.nr, i2c_dev->irq, i2c_dev->membase);
+
+       return 0;
+
+exit_clk:
+       clk_disable(i2c_dev->clk);
+       clk_unprepare(i2c_dev->clk);
+       return ret;
+}
+
+static int em_i2c_remove(struct platform_device *dev)
+{
+       struct em_i2c_device *i2c_dev = platform_get_drvdata(dev);
+
+       i2c_del_adapter(&i2c_dev->adap);
+
+       clk_disable(i2c_dev->clk);
+       clk_unprepare(i2c_dev->clk);
+
+       return 0;
+}
+
+static struct of_device_id em_i2c_ids[] = {
+       { .compatible = "renesas,em-i2c", },
+       { }
+};

you forgot the module device table for this.

+
+static struct platform_driver em_i2c_driver = {
+       .probe = em_i2c_probe,
+       .remove = em_i2c_remove,
+       .driver = {
+               .name = "em-i2c",
+               .owner = THIS_MODULE,
+               .of_match_table = em_i2c_ids,
+       }
+};
+
+
+static int __init em_i2c_init(void)
+{
+       return platform_driver_register(&em_i2c_driver);
+}
+
+static void __exit em_i2c_exit(void)
+{
+       platform_driver_unregister(&em_i2c_driver);
+}
+
+MODULE_LICENSE("GPLv2");
+
+module_init(em_i2c_init);
+module_exit(em_i2c_exit);

I think there is also a shortcut for the module init/exit for a
module that just does platform drivers.


--
Ben Dooks                               http://www.codethink.co.uk/
Senior Engineer                         Codethink - Providing Genius
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