* [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
@ 2009-05-19 9:23 Baruch Siach
[not found] ` <1242725005-6431-1-git-send-email-baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
0 siblings, 1 reply; 12+ messages in thread
From: Baruch Siach @ 2009-05-19 9:23 UTC (permalink / raw)
To: linux-i2c-u79uwXL29TY76Z2rM5mHXA; +Cc: Ben Dooks, Baruch Siach
Signed-off-by: Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
---
drivers/i2c/busses/Kconfig | 9 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-designware.c | 587 +++++++++++++++++++++++++++++++++++
3 files changed, 597 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-designware.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index f1c6ca7..cef1567 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -326,6 +326,15 @@ config I2C_DAVINCI
devices such as DaVinci NIC.
For details please see http://www.ti.com/davinci
+config I2C_DESIGNWARE
+ tristate "Synopsys DesignWare"
+ help
+ If you say yes to this option, support will be included for the
+ Synopsys DesignWare I2C adapter. Only master mode is supported.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-designware.
+
config I2C_GPIO
tristate "GPIO-based bitbanging I2C"
depends on GENERIC_GPIO
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 776acb6..c2be11e 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o
obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o
+obj-$(CONFIG_I2C_DESIGNWARE) += i2c-designware.o
obj-$(CONFIG_I2C_GPIO) += i2c-gpio.o
obj-$(CONFIG_I2C_HIGHLANDER) += i2c-highlander.o
obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o
diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c
new file mode 100644
index 0000000..0138fea
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware.c
@@ -0,0 +1,587 @@
+/*
+ * Synopsys Designware I2C adapter driver (master only).
+ *
+ * Based on the TI DAVINCI I2C adapter driver.
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ * Copyright (C) 2007 MontaVista Software Inc.
+ * Copyright (C) 2009 Provigent Ltd.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * 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.
+ * ----------------------------------------------------------------------------
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+/*
+ * Registers offset
+ */
+#define DW_IC_CON 0x0
+#define DW_IC_TAR 0x4
+#define DW_IC_DATA_CMD 0x10
+#define DW_IC_SS_SCL_HCNT 0x14
+#define DW_IC_SS_SCL_LCNT 0x18
+#define DW_IC_FS_SCL_HCNT 0x1c
+#define DW_IC_FS_SCL_LCNT 0x20
+#define DW_IC_INTR_STAT 0x2c
+#define DW_IC_INTR_MASK 0x30
+#define DW_IC_CLR_INTR 0x40
+#define DW_IC_ENABLE 0x6c
+#define DW_IC_STATUS 0x70
+#define DW_IC_TXFLR 0x74
+#define DW_IC_RXFLR 0x78
+#define DW_IC_COMP_PARAM_1 0xf4
+#define DW_IC_TX_ABRT_SOURCE 0x80
+
+#define DW_IC_CON_MASTER 0x1
+#define DW_IC_CON_SPEED_STD 0x2
+#define DW_IC_CON_SPEED_FAST 0x4
+#define DW_IC_CON_10BITADDR_MASTER 0x10
+#define DW_IC_CON_RESTART_EN 0x20
+#define DW_IC_CON_SLAVE_DISABLE 0x40
+
+#define DW_IC_INTR_TX_EMPTY 0x10
+#define DW_IC_INTR_TX_ABRT 0x40
+#define DW_IC_INTR_STOP_DET 0x200
+
+#define DW_IC_STATUS_ACTIVITY 0x1
+
+#define DW_IC_ERR_TX_ABRT 0x1
+
+/*
+ * status codes
+ */
+#define STATUS_IDLE 0x0
+#define STATUS_WRITE_IN_PROGRESS 0x1
+#define STATUS_READ_IN_PROGRESS 0x2
+
+/*
+ * hardware abort codes
+ *
+ * only expected abort codes are listed here
+ * refer to the datasheet for the full list
+ */
+#define ABRT_7B_ADDR_NOACK 0
+#define ABRT_10ADDR1_NOACK 1
+#define ABRT_10ADDR2_NOACK 2
+#define ABRT_TXDATA_NOACK 3
+#define ABRT_GCALL_NOACK 4
+#define ABRT_GCALL_READ 5
+#define ABRT_SBYTE_ACKDET 7
+#define ABRT_SBYTE_NORSTRT 9
+#define ABRT_10B_RD_NORSTRT 10
+#define ARB_MASTER_DIS 11
+#define ARB_LOST 12
+
+static char *abort_sources[] = {
+ [ABRT_7B_ADDR_NOACK] =
+ "slave address not acknowledged (7bit mode)",
+ [ABRT_10ADDR1_NOACK] =
+ "first address byte not acknowledged (10bit mode)",
+ [ABRT_10ADDR2_NOACK] =
+ "second address byte not acknowledged (10bit mode)",
+ [ABRT_TXDATA_NOACK] =
+ "data not acknowledged",
+ [ABRT_GCALL_NOACK] =
+ "no acknowledgement for a general call",
+ [ABRT_GCALL_READ] =
+ "read after general call",
+ [ABRT_SBYTE_ACKDET] =
+ "start byte acknowledged",
+ [ABRT_SBYTE_NORSTRT] =
+ "trying to send start byte when restart is disabled",
+ [ABRT_10B_RD_NORSTRT] =
+ "trying to read when restart is disabled (10bit mode)",
+ [ARB_MASTER_DIS] =
+ "trying to use disabled adapter",
+ [ARB_LOST] =
+ "lost arbitration",
+};
+
+struct dw_i2c_dev {
+ struct device *dev;
+ void __iomem *base;
+ struct completion cmd_complete;
+ struct tasklet_struct pump_msg;
+ struct mutex lock;
+ struct clk *clk;
+ int cmd_err;
+ struct i2c_msg *msgs;
+ int msgs_num;
+ int msg_write_idx;
+ int msg_read_idx;
+ int msg_err;
+ unsigned int status;
+ u16 abort_source;
+ int irq;
+ struct i2c_adapter adapter;
+ unsigned int tx_fifo_depth;
+ unsigned int rx_fifo_depth;
+};
+
+/*
+ * This functions configures I2C and enables I2C.
+ * This function is called during I2C init function.
+ */
+static int i2c_dw_init(struct dw_i2c_dev *dev)
+{
+ u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
+ u16 ic_con;
+
+ /* Disable the adapter */
+ writeb(0, dev->base + DW_IC_ENABLE);
+
+ /* set standard and fast speed deviders for high/low periods */
+ writew((input_clock_khz * 40 / 10000)+1, /* std speed high, 4us */
+ dev->base + DW_IC_SS_SCL_HCNT);
+ writew((input_clock_khz * 47 / 10000)+1, /* std speed low, 4.7us */
+ dev->base + DW_IC_SS_SCL_LCNT);
+ writew((input_clock_khz * 6 / 10000)+1, /* fast speed high, 0.6us */
+ dev->base + DW_IC_FS_SCL_HCNT);
+ writew((input_clock_khz * 13 / 10000)+1, /* fast speed low, 1.3us */
+ dev->base + DW_IC_FS_SCL_LCNT);
+
+ /* configure the i2c master */
+ ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
+ DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
+ writew(ic_con, dev->base + DW_IC_CON);
+
+ return 0;
+}
+
+/*
+ * Waiting for bus not busy
+ */
+static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
+{
+ unsigned long timeout;
+
+ timeout = jiffies + HZ;
+ while (readb(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
+ if (time_after(jiffies, timeout)) {
+ dev_warn(dev->dev,
+ "timeout waiting for bus ready\n");
+ return -ETIMEDOUT;
+ }
+ schedule_timeout(1);
+ }
+
+ return 0;
+}
+
+/*
+ * Initiate low level master read/write transaction.
+ * This function is called from i2c_dw_xfer when starting a transfer.
+ * This function is also called from dw_i2c_pump_msg to continue a transfer
+ * that is longer than the size of the TX FIFO.
+ */
+static void
+i2c_dw_xfer_msg(struct i2c_adapter *adap)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+ struct i2c_msg *msgs = dev->msgs;
+ int num = dev->msgs_num;
+ u16 ic_con, intr_mask;
+ int tx_valid_bytes = readb(dev->base + DW_IC_TXFLR);
+ int tx_limit = dev->tx_fifo_depth - tx_valid_bytes;
+ int rx_limit = dev->rx_fifo_depth - readb(dev->base + DW_IC_RXFLR)
+ - tx_valid_bytes;
+ static u16 buf_len = 0;
+ static u16 addr;
+
+ if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
+ /* Disable the adapter */
+ writeb(0, dev->base + DW_IC_ENABLE);
+
+ /* set the slave (target) address */
+ writew(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
+
+ /* if the slave address is ten bit address, enable 10BITADDR */
+ ic_con = readw(dev->base + DW_IC_CON);
+ if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
+ ic_con |= DW_IC_CON_10BITADDR_MASTER;
+ else
+ ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
+ writew(ic_con, dev->base + DW_IC_CON);
+
+ /* Enable the adapter */
+ writeb(1, dev->base + DW_IC_ENABLE);
+
+ addr = msgs[dev->msg_write_idx].addr;
+ }
+
+ for (; dev->msg_write_idx < num; dev->msg_write_idx++) {
+ static u8 *buf;
+
+ /* if target address has changed, we need to
+ * reprogram the target address in the i2c
+ * adapter when we are done with this transfer
+ */
+ if (msgs[dev->msg_write_idx].addr != addr)
+ return;
+
+ if (msgs[dev->msg_write_idx].len == 0) {
+ dev_err(dev->dev,
+ "%s: invalid message length\n", __func__);
+ dev->msg_err = -EINVAL;
+ return;
+ }
+
+ if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
+ /* new i2c_msg */
+ buf = msgs[dev->msg_write_idx].buf;
+ buf_len = msgs[dev->msg_write_idx].len;
+ }
+
+ for (; buf_len > 0 && tx_limit > 0 && rx_limit > 0; buf_len--)
+ if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
+ writew(0x100, dev->base + DW_IC_DATA_CMD);
+ rx_limit--; tx_limit--;
+ } else {
+ writew(*buf++, dev->base + DW_IC_DATA_CMD);
+ tx_limit--;
+ }
+ }
+
+ intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
+ if (buf_len > 0) { /* more bytes to be written */
+ intr_mask |= DW_IC_INTR_TX_EMPTY;
+ dev->status |= STATUS_WRITE_IN_PROGRESS;
+ } else
+ dev->status &= ~STATUS_WRITE_IN_PROGRESS;
+ writew(intr_mask, dev->base + DW_IC_INTR_MASK);
+}
+
+static void
+i2c_dw_read(struct i2c_adapter *adap)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+ struct i2c_msg *msgs = dev->msgs;
+ int num = dev->msgs_num;
+ u16 addr = msgs[dev->msg_read_idx].addr;
+ int rx_valid = readw(dev->base + DW_IC_RXFLR);
+
+ for (; dev->msg_read_idx < num; dev->msg_read_idx++) {
+ static int len;
+ static u8 *buf;
+
+ if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
+ continue;
+
+ /* different i2c client, reprogram the i2c adapter */
+ if (msgs[dev->msg_read_idx].addr != addr)
+ return;
+
+ if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
+ len = msgs[dev->msg_read_idx].len;
+ buf = msgs[dev->msg_read_idx].buf;
+ }
+
+ for (; len > 0 && rx_valid > 0; len--, rx_valid--)
+ *buf++ = readb(dev->base + DW_IC_DATA_CMD);
+
+ if (len > 0) {
+ dev->status |= STATUS_READ_IN_PROGRESS;
+ return;
+ } else
+ dev->status &= ~STATUS_READ_IN_PROGRESS;
+ }
+}
+
+/*
+ * Prepare controller for a transaction and call i2c_dw_xfer_msg
+ */
+static int
+i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+ int ret;
+
+ dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
+
+ mutex_lock(&dev->lock);
+
+ INIT_COMPLETION(dev->cmd_complete);
+ dev->msgs = msgs;
+ dev->msgs_num = num;
+ dev->cmd_err = 0;
+ dev->msg_write_idx = 0;
+ dev->msg_read_idx = 0;
+ dev->msg_err = 0;
+ dev->status = STATUS_IDLE;
+
+ ret = i2c_dw_wait_bus_not_busy(dev);
+ if (ret < 0)
+ goto done;
+
+ /* start the transfers */
+ i2c_dw_xfer_msg(adap);
+
+ /* wait for tx to complete */
+ ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
+ if (ret == 0) {
+ dev_err(dev->dev, "controller timed out\n");
+ i2c_dw_init(dev);
+ ret = -ETIMEDOUT;
+ goto done;
+ } else if (ret < 0)
+ goto done;
+
+ if (dev->msg_err) {
+ ret = dev->msg_err;
+ goto done;
+ }
+
+ /* no error */
+ if (likely(!dev->cmd_err)) {
+ /* read rx fifo, and disable the adapter */
+ do {
+ i2c_dw_read(adap);
+ } while (dev->status & STATUS_READ_IN_PROGRESS);
+ writeb(0, dev->base + DW_IC_ENABLE);
+ ret = num;
+ goto done;
+ }
+
+ /* We have an error */
+ if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
+ unsigned long abort_source = dev->abort_source;
+ int i;
+
+ for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) {
+ dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
+ }
+ }
+ ret = -EIO;
+
+done:
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+static u32 i2c_dw_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
+}
+
+static void dw_i2c_pump_msg(unsigned long data)
+{
+ struct dw_i2c_dev *dev = (struct dw_i2c_dev *) data;
+ u16 intr_mask;
+
+ i2c_dw_read(&dev->adapter);
+ i2c_dw_xfer_msg(&dev->adapter);
+
+ intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
+ if (dev->status & STATUS_WRITE_IN_PROGRESS)
+ intr_mask |= DW_IC_INTR_TX_EMPTY;
+ writew(intr_mask, dev->base + DW_IC_INTR_MASK);
+}
+
+/*
+ * Interrupt service routine. This gets called whenever an I2C interrupt
+ * occurs.
+ */
+static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
+{
+ struct dw_i2c_dev *dev = dev_id;
+ u16 stat;
+
+ stat = readw(dev->base + DW_IC_INTR_STAT);
+ dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
+ if (stat & DW_IC_INTR_TX_ABRT) {
+ dev->abort_source = readw(dev->base + DW_IC_TX_ABRT_SOURCE);
+ dev->cmd_err |= DW_IC_ERR_TX_ABRT;
+ dev->status = STATUS_IDLE;
+ } else if (stat & DW_IC_INTR_TX_EMPTY)
+ tasklet_schedule(&dev->pump_msg);
+
+ readb(dev->base + DW_IC_CLR_INTR); /* clear interrupts */
+ writew(0, dev->base + DW_IC_INTR_MASK); /* disable interrupts */
+ if (stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
+ complete(&dev->cmd_complete);
+
+ return IRQ_HANDLED;
+}
+
+static struct i2c_algorithm i2c_dw_algo = {
+ .master_xfer = i2c_dw_xfer,
+ .functionality = i2c_dw_func,
+};
+
+static int dw_i2c_probe(struct platform_device *pdev)
+{
+ struct dw_i2c_dev *dev;
+ struct i2c_adapter *adap;
+ struct resource *mem, *irq, *ioarea;
+ int r;
+
+ /* NOTE: driver uses the static register mapping */
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!mem) {
+ dev_err(&pdev->dev, "no mem resource?\n");
+ return -ENODEV;
+ }
+
+ irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!irq) {
+ dev_err(&pdev->dev, "no irq resource?\n");
+ return -ENODEV;
+ }
+
+ ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
+ pdev->name);
+ if (!ioarea) {
+ dev_err(&pdev->dev, "I2C region already claimed\n");
+ return -EBUSY;
+ }
+
+ dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
+ if (!dev) {
+ r = -ENOMEM;
+ goto err_release_region;
+ }
+
+ init_completion(&dev->cmd_complete);
+ tasklet_init(&dev->pump_msg, dw_i2c_pump_msg, (unsigned long) dev);
+ mutex_init(&dev->lock);
+ dev->dev = get_device(&pdev->dev);
+ dev->irq = irq->start;
+ platform_set_drvdata(pdev, dev);
+
+ dev->clk = clk_get(&pdev->dev, "I2CCLK");
+ if (IS_ERR(dev->clk)) {
+ r = -ENODEV;
+ goto err_free_mem;
+ }
+ clk_enable(dev->clk);
+
+ dev->base = ioremap(mem->start, mem->end - mem->start + 1);
+ if (dev->base == NULL) {
+ dev_err(&pdev->dev, "failure mapping io resources\n");
+ r = -EBUSY;
+ goto err_unuse_clocks;
+ }
+ dev->tx_fifo_depth =
+ ((readl(dev->base + DW_IC_COMP_PARAM_1) & 0x00ff0000) >> 16) + 1;
+ dev->rx_fifo_depth =
+ ((readl(dev->base + DW_IC_COMP_PARAM_1) & 0x0000ff00) >> 8) + 1;
+ i2c_dw_init(dev);
+
+ writew(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
+ r = request_irq(dev->irq, i2c_dw_isr, 0, pdev->name, dev);
+ if (r) {
+ dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
+ goto err_iounmap;
+ }
+
+ adap = &dev->adapter;
+ i2c_set_adapdata(adap, dev);
+ adap->owner = THIS_MODULE;
+ adap->class = I2C_CLASS_HWMON;
+ strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
+ sizeof(adap->name));
+ adap->algo = &i2c_dw_algo;
+ adap->dev.parent = &pdev->dev;
+
+ adap->nr = pdev->id;
+ r = i2c_add_numbered_adapter(adap);
+ if (r) {
+ dev_err(&pdev->dev, "failure adding adapter\n");
+ goto err_free_irq;
+ }
+
+ return 0;
+
+err_free_irq:
+ free_irq(dev->irq, dev);
+err_iounmap:
+ iounmap(dev->base);
+err_unuse_clocks:
+ clk_disable(dev->clk);
+ clk_put(dev->clk);
+ dev->clk = NULL;
+err_free_mem:
+ platform_set_drvdata(pdev, NULL);
+ put_device(&pdev->dev);
+ kfree(dev);
+err_release_region:
+ release_mem_region(mem->start, (mem->end - mem->start) + 1);
+
+ return r;
+}
+
+static int dw_i2c_remove(struct platform_device *pdev)
+{
+ struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+ struct resource *mem;
+
+ platform_set_drvdata(pdev, NULL);
+ i2c_del_adapter(&dev->adapter);
+ put_device(&pdev->dev);
+
+ clk_disable(dev->clk);
+ clk_put(dev->clk);
+ dev->clk = NULL;
+
+ writeb(0, dev->base + DW_IC_ENABLE);
+ free_irq(dev->irq, dev);
+ kfree(dev);
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ release_mem_region(mem->start, (mem->end - mem->start) + 1);
+ return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:i2c_designware");
+
+static struct platform_driver dw_i2c_driver = {
+ .probe = dw_i2c_probe,
+ .remove = dw_i2c_remove,
+ .driver = {
+ .name = "i2c_designware",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init dw_i2c_init_driver(void)
+{
+ return platform_driver_register(&dw_i2c_driver);
+}
+module_init(dw_i2c_init_driver);
+
+static void __exit dw_i2c_exit_driver(void)
+{
+ platform_driver_unregister(&dw_i2c_driver);
+}
+module_exit(dw_i2c_exit_driver);
+
+MODULE_AUTHOR("Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>");
+MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
+MODULE_LICENSE("GPL");
--
1.6.2.4
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
[not found] ` <1242725005-6431-1-git-send-email-baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
@ 2009-05-26 21:39 ` Ben Dooks
[not found] ` <20090526213917.GH23114-elnMNo+KYs3pIgCt6eIbzw@public.gmane.org>
2009-05-27 19:23 ` Linus Walleij
1 sibling, 1 reply; 12+ messages in thread
From: Ben Dooks @ 2009-05-26 21:39 UTC (permalink / raw)
To: Baruch Siach; +Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA, Ben Dooks
On Tue, May 19, 2009 at 12:23:25PM +0300, Baruch Siach wrote:
Please provide an actual description here. A brief subject
isn't enough!
> Signed-off-by: Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
> ---
> drivers/i2c/busses/Kconfig | 9 +
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-designware.c | 587 +++++++++++++++++++++++++++++++++++
> 3 files changed, 597 insertions(+), 0 deletions(-)
> create mode 100644 drivers/i2c/busses/i2c-designware.c
>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index f1c6ca7..cef1567 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -326,6 +326,15 @@ config I2C_DAVINCI
> devices such as DaVinci NIC.
> For details please see http://www.ti.com/davinci
>
> +config I2C_DESIGNWARE
> + tristate "Synopsys DesignWare"
> + help
> + If you say yes to this option, support will be included for the
> + Synopsys DesignWare I2C adapter. Only master mode is supported.
> +
> + This driver can also be built as a module. If so, the module
> + will be called i2c-designware.
> +
> config I2C_GPIO
> tristate "GPIO-based bitbanging I2C"
> depends on GENERIC_GPIO
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index 776acb6..c2be11e 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -30,6 +30,7 @@ obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
> obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o
> obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
> obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o
> +obj-$(CONFIG_I2C_DESIGNWARE) += i2c-designware.o
> obj-$(CONFIG_I2C_GPIO) += i2c-gpio.o
> obj-$(CONFIG_I2C_HIGHLANDER) += i2c-highlander.o
> obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o
> diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c
> new file mode 100644
> index 0000000..0138fea
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-designware.c
> @@ -0,0 +1,587 @@
> +/*
> + * Synopsys Designware I2C adapter driver (master only).
> + *
> + * Based on the TI DAVINCI I2C adapter driver.
> + *
> + * Copyright (C) 2006 Texas Instruments.
> + * Copyright (C) 2007 MontaVista Software Inc.
> + * Copyright (C) 2009 Provigent Ltd.
> + *
> + * ----------------------------------------------------------------------------
> + *
> + * 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.
> + * ----------------------------------------------------------------------------
> + *
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/clk.h>
> +#include <linux/errno.h>
> +#include <linux/sched.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +
> +/*
> + * Registers offset
> + */
> +#define DW_IC_CON 0x0
> +#define DW_IC_TAR 0x4
> +#define DW_IC_DATA_CMD 0x10
> +#define DW_IC_SS_SCL_HCNT 0x14
> +#define DW_IC_SS_SCL_LCNT 0x18
> +#define DW_IC_FS_SCL_HCNT 0x1c
> +#define DW_IC_FS_SCL_LCNT 0x20
> +#define DW_IC_INTR_STAT 0x2c
> +#define DW_IC_INTR_MASK 0x30
> +#define DW_IC_CLR_INTR 0x40
> +#define DW_IC_ENABLE 0x6c
> +#define DW_IC_STATUS 0x70
> +#define DW_IC_TXFLR 0x74
> +#define DW_IC_RXFLR 0x78
> +#define DW_IC_COMP_PARAM_1 0xf4
> +#define DW_IC_TX_ABRT_SOURCE 0x80
> +
> +#define DW_IC_CON_MASTER 0x1
> +#define DW_IC_CON_SPEED_STD 0x2
> +#define DW_IC_CON_SPEED_FAST 0x4
> +#define DW_IC_CON_10BITADDR_MASTER 0x10
> +#define DW_IC_CON_RESTART_EN 0x20
> +#define DW_IC_CON_SLAVE_DISABLE 0x40
> +
> +#define DW_IC_INTR_TX_EMPTY 0x10
> +#define DW_IC_INTR_TX_ABRT 0x40
> +#define DW_IC_INTR_STOP_DET 0x200
> +
> +#define DW_IC_STATUS_ACTIVITY 0x1
> +
> +#define DW_IC_ERR_TX_ABRT 0x1
> +
> +/*
> + * status codes
> + */
> +#define STATUS_IDLE 0x0
> +#define STATUS_WRITE_IN_PROGRESS 0x1
> +#define STATUS_READ_IN_PROGRESS 0x2
> +
> +/*
> + * hardware abort codes
> + *
> + * only expected abort codes are listed here
> + * refer to the datasheet for the full list
> + */
> +#define ABRT_7B_ADDR_NOACK 0
> +#define ABRT_10ADDR1_NOACK 1
> +#define ABRT_10ADDR2_NOACK 2
> +#define ABRT_TXDATA_NOACK 3
> +#define ABRT_GCALL_NOACK 4
> +#define ABRT_GCALL_READ 5
> +#define ABRT_SBYTE_ACKDET 7
> +#define ABRT_SBYTE_NORSTRT 9
> +#define ABRT_10B_RD_NORSTRT 10
> +#define ARB_MASTER_DIS 11
> +#define ARB_LOST 12
> +
> +static char *abort_sources[] = {
> + [ABRT_7B_ADDR_NOACK] =
> + "slave address not acknowledged (7bit mode)",
> + [ABRT_10ADDR1_NOACK] =
> + "first address byte not acknowledged (10bit mode)",
> + [ABRT_10ADDR2_NOACK] =
> + "second address byte not acknowledged (10bit mode)",
> + [ABRT_TXDATA_NOACK] =
> + "data not acknowledged",
> + [ABRT_GCALL_NOACK] =
> + "no acknowledgement for a general call",
> + [ABRT_GCALL_READ] =
> + "read after general call",
> + [ABRT_SBYTE_ACKDET] =
> + "start byte acknowledged",
> + [ABRT_SBYTE_NORSTRT] =
> + "trying to send start byte when restart is disabled",
> + [ABRT_10B_RD_NORSTRT] =
> + "trying to read when restart is disabled (10bit mode)",
> + [ARB_MASTER_DIS] =
> + "trying to use disabled adapter",
> + [ARB_LOST] =
> + "lost arbitration",
> +};
> +
> +struct dw_i2c_dev {
> + struct device *dev;
> + void __iomem *base;
> + struct completion cmd_complete;
> + struct tasklet_struct pump_msg;
> + struct mutex lock;
> + struct clk *clk;
> + int cmd_err;
> + struct i2c_msg *msgs;
> + int msgs_num;
> + int msg_write_idx;
> + int msg_read_idx;
> + int msg_err;
> + unsigned int status;
> + u16 abort_source;
> + int irq;
> + struct i2c_adapter adapter;
> + unsigned int tx_fifo_depth;
> + unsigned int rx_fifo_depth;
> +};
> +
> +/*
> + * This functions configures I2C and enables I2C.
> + * This function is called during I2C init function.
> + */
> +static int i2c_dw_init(struct dw_i2c_dev *dev)
> +{
> + u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
> + u16 ic_con;
> +
> + /* Disable the adapter */
> + writeb(0, dev->base + DW_IC_ENABLE);
> +
> + /* set standard and fast speed deviders for high/low periods */
> + writew((input_clock_khz * 40 / 10000)+1, /* std speed high, 4us */
> + dev->base + DW_IC_SS_SCL_HCNT);
> + writew((input_clock_khz * 47 / 10000)+1, /* std speed low, 4.7us */
> + dev->base + DW_IC_SS_SCL_LCNT);
> + writew((input_clock_khz * 6 / 10000)+1, /* fast speed high, 0.6us */
> + dev->base + DW_IC_FS_SCL_HCNT);
> + writew((input_clock_khz * 13 / 10000)+1, /* fast speed low, 1.3us */
> + dev->base + DW_IC_FS_SCL_LCNT);
> +
> + /* configure the i2c master */
> + ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
> + DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
> + writew(ic_con, dev->base + DW_IC_CON);
> +
> + return 0;
> +}
> +
> +/*
> + * Waiting for bus not busy
> + */
> +static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
> +{
> + unsigned long timeout;
> +
> + timeout = jiffies + HZ;
> + while (readb(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
> + if (time_after(jiffies, timeout)) {
> + dev_warn(dev->dev,
> + "timeout waiting for bus ready\n");
> + return -ETIMEDOUT;
> + }
> + schedule_timeout(1);
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * Initiate low level master read/write transaction.
> + * This function is called from i2c_dw_xfer when starting a transfer.
> + * This function is also called from dw_i2c_pump_msg to continue a transfer
> + * that is longer than the size of the TX FIFO.
> + */
> +static void
> +i2c_dw_xfer_msg(struct i2c_adapter *adap)
> +{
> + struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
> + struct i2c_msg *msgs = dev->msgs;
> + int num = dev->msgs_num;
> + u16 ic_con, intr_mask;
> + int tx_valid_bytes = readb(dev->base + DW_IC_TXFLR);
> + int tx_limit = dev->tx_fifo_depth - tx_valid_bytes;
> + int rx_limit = dev->rx_fifo_depth - readb(dev->base + DW_IC_RXFLR)
> + - tx_valid_bytes;
hmm, sure you want tx_valid_bytes for rx_limit calculation?
> + static u16 buf_len = 0;
> + static u16 addr;
> +
> + if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
> + /* Disable the adapter */
> + writeb(0, dev->base + DW_IC_ENABLE);
> +
> + /* set the slave (target) address */
> + writew(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
> +
> + /* if the slave address is ten bit address, enable 10BITADDR */
> + ic_con = readw(dev->base + DW_IC_CON);
> + if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
> + ic_con |= DW_IC_CON_10BITADDR_MASTER;
> + else
> + ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
> + writew(ic_con, dev->base + DW_IC_CON);
> +
> + /* Enable the adapter */
> + writeb(1, dev->base + DW_IC_ENABLE);
> +
> + addr = msgs[dev->msg_write_idx].addr;
> + }
> +
> + for (; dev->msg_write_idx < num; dev->msg_write_idx++) {
> + static u8 *buf;
> +
> + /* if target address has changed, we need to
> + * reprogram the target address in the i2c
> + * adapter when we are done with this transfer
> + */
> + if (msgs[dev->msg_write_idx].addr != addr)
> + return;
> +
> + if (msgs[dev->msg_write_idx].len == 0) {
> + dev_err(dev->dev,
> + "%s: invalid message length\n", __func__);
> + dev->msg_err = -EINVAL;
> + return;
> + }
> +
> + if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
> + /* new i2c_msg */
> + buf = msgs[dev->msg_write_idx].buf;
> + buf_len = msgs[dev->msg_write_idx].len;
> + }
> +
> + for (; buf_len > 0 && tx_limit > 0 && rx_limit > 0; buf_len--)
> + if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
> + writew(0x100, dev->base + DW_IC_DATA_CMD);
> + rx_limit--; tx_limit--;
> + } else {
> + writew(*buf++, dev->base + DW_IC_DATA_CMD);
> + tx_limit--;
> + }
> + }
> +
> + intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
> + if (buf_len > 0) { /* more bytes to be written */
> + intr_mask |= DW_IC_INTR_TX_EMPTY;
> + dev->status |= STATUS_WRITE_IN_PROGRESS;
> + } else
> + dev->status &= ~STATUS_WRITE_IN_PROGRESS;
> + writew(intr_mask, dev->base + DW_IC_INTR_MASK);
> +}
> +
> +static void
> +i2c_dw_read(struct i2c_adapter *adap)
> +{
> + struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
> + struct i2c_msg *msgs = dev->msgs;
> + int num = dev->msgs_num;
> + u16 addr = msgs[dev->msg_read_idx].addr;
> + int rx_valid = readw(dev->base + DW_IC_RXFLR);
> +
> + for (; dev->msg_read_idx < num; dev->msg_read_idx++) {
> + static int len;
> + static u8 *buf;
sure you want this to be static? if so, a note explaining what it
is being used for.
> +
> + if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
> + continue;
> +
> + /* different i2c client, reprogram the i2c adapter */
> + if (msgs[dev->msg_read_idx].addr != addr)
> + return;
> +
> + if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
> + len = msgs[dev->msg_read_idx].len;
> + buf = msgs[dev->msg_read_idx].buf;
> + }
> +
> + for (; len > 0 && rx_valid > 0; len--, rx_valid--)
> + *buf++ = readb(dev->base + DW_IC_DATA_CMD);
> +
> + if (len > 0) {
> + dev->status |= STATUS_READ_IN_PROGRESS;
> + return;
> + } else
> + dev->status &= ~STATUS_READ_IN_PROGRESS;
> + }
> +}
> +
> +/*
> + * Prepare controller for a transaction and call i2c_dw_xfer_msg
> + */
> +static int
> +i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
> +{
> + struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
> + int ret;
> +
> + dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
> +
> + mutex_lock(&dev->lock);
> +
> + INIT_COMPLETION(dev->cmd_complete);
> + dev->msgs = msgs;
> + dev->msgs_num = num;
> + dev->cmd_err = 0;
> + dev->msg_write_idx = 0;
> + dev->msg_read_idx = 0;
> + dev->msg_err = 0;
> + dev->status = STATUS_IDLE;
> +
> + ret = i2c_dw_wait_bus_not_busy(dev);
> + if (ret < 0)
> + goto done;
> +
> + /* start the transfers */
> + i2c_dw_xfer_msg(adap);
> +
> + /* wait for tx to complete */
> + ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
> + if (ret == 0) {
> + dev_err(dev->dev, "controller timed out\n");
> + i2c_dw_init(dev);
> + ret = -ETIMEDOUT;
> + goto done;
> + } else if (ret < 0)
> + goto done;
> +
> + if (dev->msg_err) {
> + ret = dev->msg_err;
> + goto done;
> + }
> +
> + /* no error */
> + if (likely(!dev->cmd_err)) {
> + /* read rx fifo, and disable the adapter */
> + do {
> + i2c_dw_read(adap);
> + } while (dev->status & STATUS_READ_IN_PROGRESS);
> + writeb(0, dev->base + DW_IC_ENABLE);
> + ret = num;
> + goto done;
> + }
> +
> + /* We have an error */
> + if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
> + unsigned long abort_source = dev->abort_source;
> + int i;
> +
> + for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) {
> + dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
> + }
> + }
> + ret = -EIO;
> +
> +done:
> + mutex_unlock(&dev->lock);
> +
> + return ret;
> +}
> +
> +static u32 i2c_dw_func(struct i2c_adapter *adap)
> +{
> + return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
> +}
> +
> +static void dw_i2c_pump_msg(unsigned long data)
> +{
> + struct dw_i2c_dev *dev = (struct dw_i2c_dev *) data;
> + u16 intr_mask;
> +
> + i2c_dw_read(&dev->adapter);
> + i2c_dw_xfer_msg(&dev->adapter);
> +
> + intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
> + if (dev->status & STATUS_WRITE_IN_PROGRESS)
> + intr_mask |= DW_IC_INTR_TX_EMPTY;
> + writew(intr_mask, dev->base + DW_IC_INTR_MASK);
> +}
> +
> +/*
> + * Interrupt service routine. This gets called whenever an I2C interrupt
> + * occurs.
> + */
> +static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
> +{
> + struct dw_i2c_dev *dev = dev_id;
> + u16 stat;
> +
> + stat = readw(dev->base + DW_IC_INTR_STAT);
> + dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
> + if (stat & DW_IC_INTR_TX_ABRT) {
> + dev->abort_source = readw(dev->base + DW_IC_TX_ABRT_SOURCE);
> + dev->cmd_err |= DW_IC_ERR_TX_ABRT;
> + dev->status = STATUS_IDLE;
> + } else if (stat & DW_IC_INTR_TX_EMPTY)
> + tasklet_schedule(&dev->pump_msg);
> +
> + readb(dev->base + DW_IC_CLR_INTR); /* clear interrupts */
> + writew(0, dev->base + DW_IC_INTR_MASK); /* disable interrupts */
> + if (stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
> + complete(&dev->cmd_complete);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static struct i2c_algorithm i2c_dw_algo = {
> + .master_xfer = i2c_dw_xfer,
> + .functionality = i2c_dw_func,
> +};
> +
> +static int dw_i2c_probe(struct platform_device *pdev)
> +{
> + struct dw_i2c_dev *dev;
> + struct i2c_adapter *adap;
> + struct resource *mem, *irq, *ioarea;
> + int r;
> +
> + /* NOTE: driver uses the static register mapping */
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!mem) {
> + dev_err(&pdev->dev, "no mem resource?\n");
> + return -ENODEV;
> + }
ENODEV is not a good error return here, it won't get repoted
to the user as the probe takes this as there was nothing there
not a 'it was there, but something went wrong'. try -EINVAL instead.
> + irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> + if (!irq) {
> + dev_err(&pdev->dev, "no irq resource?\n");
> + return -ENODEV;
> + }
ditto.
> + ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
> + pdev->name);
> + if (!ioarea) {
> + dev_err(&pdev->dev, "I2C region already claimed\n");
> + return -EBUSY;
> + }
> +
> + dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
> + if (!dev) {
> + r = -ENOMEM;
> + goto err_release_region;
> + }
> +
> + init_completion(&dev->cmd_complete);
> + tasklet_init(&dev->pump_msg, dw_i2c_pump_msg, (unsigned long) dev);
> + mutex_init(&dev->lock);
> + dev->dev = get_device(&pdev->dev);
> + dev->irq = irq->start;
> + platform_set_drvdata(pdev, dev);
> +
> + dev->clk = clk_get(&pdev->dev, "I2CCLK");
> + if (IS_ERR(dev->clk)) {
> + r = -ENODEV;
> + goto err_free_mem;
> + }
and again.
> + clk_enable(dev->clk);
> +
> + dev->base = ioremap(mem->start, mem->end - mem->start + 1);
> + if (dev->base == NULL) {
> + dev_err(&pdev->dev, "failure mapping io resources\n");
> + r = -EBUSY;
> + goto err_unuse_clocks;
> + }
> + dev->tx_fifo_depth =
> + ((readl(dev->base + DW_IC_COMP_PARAM_1) & 0x00ff0000) >> 16) + 1;
> + dev->rx_fifo_depth =
> + ((readl(dev->base + DW_IC_COMP_PARAM_1) & 0x0000ff00) >> 8) + 1;
> + i2c_dw_init(dev);
> +
> + writew(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
> + r = request_irq(dev->irq, i2c_dw_isr, 0, pdev->name, dev);
> + if (r) {
> + dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
> + goto err_iounmap;
> + }
> +
> + adap = &dev->adapter;
> + i2c_set_adapdata(adap, dev);
> + adap->owner = THIS_MODULE;
> + adap->class = I2C_CLASS_HWMON;
> + strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
> + sizeof(adap->name));
> + adap->algo = &i2c_dw_algo;
> + adap->dev.parent = &pdev->dev;
> +
> + adap->nr = pdev->id;
> + r = i2c_add_numbered_adapter(adap);
> + if (r) {
> + dev_err(&pdev->dev, "failure adding adapter\n");
> + goto err_free_irq;
> + }
> +
> + return 0;
> +
> +err_free_irq:
> + free_irq(dev->irq, dev);
> +err_iounmap:
> + iounmap(dev->base);
> +err_unuse_clocks:
> + clk_disable(dev->clk);
> + clk_put(dev->clk);
> + dev->clk = NULL;
> +err_free_mem:
> + platform_set_drvdata(pdev, NULL);
> + put_device(&pdev->dev);
> + kfree(dev);
> +err_release_region:
> + release_mem_region(mem->start, (mem->end - mem->start) + 1);
there's a resource_size() call that does that job for you.
> + return r;
> +}
> +
> +static int dw_i2c_remove(struct platform_device *pdev)
> +{
> + struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
> + struct resource *mem;
> +
> + platform_set_drvdata(pdev, NULL);
> + i2c_del_adapter(&dev->adapter);
> + put_device(&pdev->dev);
> +
> + clk_disable(dev->clk);
> + clk_put(dev->clk);
> + dev->clk = NULL;
> +
> + writeb(0, dev->base + DW_IC_ENABLE);
> + free_irq(dev->irq, dev);
> + kfree(dev);
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + release_mem_region(mem->start, (mem->end - mem->start) + 1);
> + return 0;
> +}
> +
> +/* work with hotplug and coldplug */
> +MODULE_ALIAS("platform:i2c_designware");
> +
> +static struct platform_driver dw_i2c_driver = {
> + .probe = dw_i2c_probe,
> + .remove = dw_i2c_remove,
> + .driver = {
> + .name = "i2c_designware",
> + .owner = THIS_MODULE,
> + },
> +};
> +
> +static int __init dw_i2c_init_driver(void)
> +{
> + return platform_driver_register(&dw_i2c_driver);
> +}
> +module_init(dw_i2c_init_driver);
> +
> +static void __exit dw_i2c_exit_driver(void)
> +{
> + platform_driver_unregister(&dw_i2c_driver);
> +}
> +module_exit(dw_i2c_exit_driver);
> +
> +MODULE_AUTHOR("Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>");
> +MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
> +MODULE_LICENSE("GPL");
please fix the few problems found and it can be merged.
--
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)
'a smiley only costs 4 bytes'
^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
[not found] ` <20090526213917.GH23114-elnMNo+KYs3pIgCt6eIbzw@public.gmane.org>
@ 2009-05-27 4:26 ` Baruch Siach
[not found] ` <1243398392-1516-1-git-send-email-baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
0 siblings, 1 reply; 12+ messages in thread
From: Baruch Siach @ 2009-05-27 4:26 UTC (permalink / raw)
To: linux-i2c-u79uwXL29TY76Z2rM5mHXA; +Cc: Ben Dooks, Baruch Siach
The i2c Linux driver for the DesignWare i2c block of Synopsys, which is meant
for AMBA Peripheral Bus. This i2c block is used on SoC chips like the ARM9
based PVG610.
Signed-off-by: Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
---
drivers/i2c/busses/Kconfig | 9 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-designware.c | 587 +++++++++++++++++++++++++++++++++++
3 files changed, 597 insertions(+), 0 deletions(-)
create mode 100644 drivers/i2c/busses/i2c-designware.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index f1c6ca7..cef1567 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -326,6 +326,15 @@ config I2C_DAVINCI
devices such as DaVinci NIC.
For details please see http://www.ti.com/davinci
+config I2C_DESIGNWARE
+ tristate "Synopsys DesignWare"
+ help
+ If you say yes to this option, support will be included for the
+ Synopsys DesignWare I2C adapter. Only master mode is supported.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-designware.
+
config I2C_GPIO
tristate "GPIO-based bitbanging I2C"
depends on GENERIC_GPIO
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 776acb6..c2be11e 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o
obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o
+obj-$(CONFIG_I2C_DESIGNWARE) += i2c-designware.o
obj-$(CONFIG_I2C_GPIO) += i2c-gpio.o
obj-$(CONFIG_I2C_HIGHLANDER) += i2c-highlander.o
obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o
diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c
new file mode 100644
index 0000000..0138fea
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware.c
@@ -0,0 +1,587 @@
+/*
+ * Synopsys Designware I2C adapter driver (master only).
+ *
+ * Based on the TI DAVINCI I2C adapter driver.
+ *
+ * Copyright (C) 2006 Texas Instruments.
+ * Copyright (C) 2007 MontaVista Software Inc.
+ * Copyright (C) 2009 Provigent Ltd.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * 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.
+ * ----------------------------------------------------------------------------
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+/*
+ * Registers offset
+ */
+#define DW_IC_CON 0x0
+#define DW_IC_TAR 0x4
+#define DW_IC_DATA_CMD 0x10
+#define DW_IC_SS_SCL_HCNT 0x14
+#define DW_IC_SS_SCL_LCNT 0x18
+#define DW_IC_FS_SCL_HCNT 0x1c
+#define DW_IC_FS_SCL_LCNT 0x20
+#define DW_IC_INTR_STAT 0x2c
+#define DW_IC_INTR_MASK 0x30
+#define DW_IC_CLR_INTR 0x40
+#define DW_IC_ENABLE 0x6c
+#define DW_IC_STATUS 0x70
+#define DW_IC_TXFLR 0x74
+#define DW_IC_RXFLR 0x78
+#define DW_IC_COMP_PARAM_1 0xf4
+#define DW_IC_TX_ABRT_SOURCE 0x80
+
+#define DW_IC_CON_MASTER 0x1
+#define DW_IC_CON_SPEED_STD 0x2
+#define DW_IC_CON_SPEED_FAST 0x4
+#define DW_IC_CON_10BITADDR_MASTER 0x10
+#define DW_IC_CON_RESTART_EN 0x20
+#define DW_IC_CON_SLAVE_DISABLE 0x40
+
+#define DW_IC_INTR_TX_EMPTY 0x10
+#define DW_IC_INTR_TX_ABRT 0x40
+#define DW_IC_INTR_STOP_DET 0x200
+
+#define DW_IC_STATUS_ACTIVITY 0x1
+
+#define DW_IC_ERR_TX_ABRT 0x1
+
+/*
+ * status codes
+ */
+#define STATUS_IDLE 0x0
+#define STATUS_WRITE_IN_PROGRESS 0x1
+#define STATUS_READ_IN_PROGRESS 0x2
+
+/*
+ * hardware abort codes
+ *
+ * only expected abort codes are listed here
+ * refer to the datasheet for the full list
+ */
+#define ABRT_7B_ADDR_NOACK 0
+#define ABRT_10ADDR1_NOACK 1
+#define ABRT_10ADDR2_NOACK 2
+#define ABRT_TXDATA_NOACK 3
+#define ABRT_GCALL_NOACK 4
+#define ABRT_GCALL_READ 5
+#define ABRT_SBYTE_ACKDET 7
+#define ABRT_SBYTE_NORSTRT 9
+#define ABRT_10B_RD_NORSTRT 10
+#define ARB_MASTER_DIS 11
+#define ARB_LOST 12
+
+static char *abort_sources[] = {
+ [ABRT_7B_ADDR_NOACK] =
+ "slave address not acknowledged (7bit mode)",
+ [ABRT_10ADDR1_NOACK] =
+ "first address byte not acknowledged (10bit mode)",
+ [ABRT_10ADDR2_NOACK] =
+ "second address byte not acknowledged (10bit mode)",
+ [ABRT_TXDATA_NOACK] =
+ "data not acknowledged",
+ [ABRT_GCALL_NOACK] =
+ "no acknowledgement for a general call",
+ [ABRT_GCALL_READ] =
+ "read after general call",
+ [ABRT_SBYTE_ACKDET] =
+ "start byte acknowledged",
+ [ABRT_SBYTE_NORSTRT] =
+ "trying to send start byte when restart is disabled",
+ [ABRT_10B_RD_NORSTRT] =
+ "trying to read when restart is disabled (10bit mode)",
+ [ARB_MASTER_DIS] =
+ "trying to use disabled adapter",
+ [ARB_LOST] =
+ "lost arbitration",
+};
+
+struct dw_i2c_dev {
+ struct device *dev;
+ void __iomem *base;
+ struct completion cmd_complete;
+ struct tasklet_struct pump_msg;
+ struct mutex lock;
+ struct clk *clk;
+ int cmd_err;
+ struct i2c_msg *msgs;
+ int msgs_num;
+ int msg_write_idx;
+ int msg_read_idx;
+ int msg_err;
+ unsigned int status;
+ u16 abort_source;
+ int irq;
+ struct i2c_adapter adapter;
+ unsigned int tx_fifo_depth;
+ unsigned int rx_fifo_depth;
+};
+
+/*
+ * This functions configures I2C and enables I2C.
+ * This function is called during I2C init function.
+ */
+static int i2c_dw_init(struct dw_i2c_dev *dev)
+{
+ u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
+ u16 ic_con;
+
+ /* Disable the adapter */
+ writeb(0, dev->base + DW_IC_ENABLE);
+
+ /* set standard and fast speed deviders for high/low periods */
+ writew((input_clock_khz * 40 / 10000)+1, /* std speed high, 4us */
+ dev->base + DW_IC_SS_SCL_HCNT);
+ writew((input_clock_khz * 47 / 10000)+1, /* std speed low, 4.7us */
+ dev->base + DW_IC_SS_SCL_LCNT);
+ writew((input_clock_khz * 6 / 10000)+1, /* fast speed high, 0.6us */
+ dev->base + DW_IC_FS_SCL_HCNT);
+ writew((input_clock_khz * 13 / 10000)+1, /* fast speed low, 1.3us */
+ dev->base + DW_IC_FS_SCL_LCNT);
+
+ /* configure the i2c master */
+ ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
+ DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
+ writew(ic_con, dev->base + DW_IC_CON);
+
+ return 0;
+}
+
+/*
+ * Waiting for bus not busy
+ */
+static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
+{
+ unsigned long timeout;
+
+ timeout = jiffies + HZ;
+ while (readb(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
+ if (time_after(jiffies, timeout)) {
+ dev_warn(dev->dev,
+ "timeout waiting for bus ready\n");
+ return -ETIMEDOUT;
+ }
+ schedule_timeout(1);
+ }
+
+ return 0;
+}
+
+/*
+ * Initiate low level master read/write transaction.
+ * This function is called from i2c_dw_xfer when starting a transfer.
+ * This function is also called from dw_i2c_pump_msg to continue a transfer
+ * that is longer than the size of the TX FIFO.
+ */
+static void
+i2c_dw_xfer_msg(struct i2c_adapter *adap)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+ struct i2c_msg *msgs = dev->msgs;
+ int num = dev->msgs_num;
+ u16 ic_con, intr_mask;
+ int tx_valid_bytes = readb(dev->base + DW_IC_TXFLR);
+ int tx_limit = dev->tx_fifo_depth - tx_valid_bytes;
+ int rx_limit = dev->rx_fifo_depth - readb(dev->base + DW_IC_RXFLR)
+ - tx_valid_bytes;
+ static u16 buf_len = 0;
+ static u16 addr;
+
+ if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
+ /* Disable the adapter */
+ writeb(0, dev->base + DW_IC_ENABLE);
+
+ /* set the slave (target) address */
+ writew(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
+
+ /* if the slave address is ten bit address, enable 10BITADDR */
+ ic_con = readw(dev->base + DW_IC_CON);
+ if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
+ ic_con |= DW_IC_CON_10BITADDR_MASTER;
+ else
+ ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
+ writew(ic_con, dev->base + DW_IC_CON);
+
+ /* Enable the adapter */
+ writeb(1, dev->base + DW_IC_ENABLE);
+
+ addr = msgs[dev->msg_write_idx].addr;
+ }
+
+ for (; dev->msg_write_idx < num; dev->msg_write_idx++) {
+ static u8 *buf;
+
+ /* if target address has changed, we need to
+ * reprogram the target address in the i2c
+ * adapter when we are done with this transfer
+ */
+ if (msgs[dev->msg_write_idx].addr != addr)
+ return;
+
+ if (msgs[dev->msg_write_idx].len == 0) {
+ dev_err(dev->dev,
+ "%s: invalid message length\n", __func__);
+ dev->msg_err = -EINVAL;
+ return;
+ }
+
+ if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
+ /* new i2c_msg */
+ buf = msgs[dev->msg_write_idx].buf;
+ buf_len = msgs[dev->msg_write_idx].len;
+ }
+
+ for (; buf_len > 0 && tx_limit > 0 && rx_limit > 0; buf_len--)
+ if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
+ writew(0x100, dev->base + DW_IC_DATA_CMD);
+ rx_limit--; tx_limit--;
+ } else {
+ writew(*buf++, dev->base + DW_IC_DATA_CMD);
+ tx_limit--;
+ }
+ }
+
+ intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
+ if (buf_len > 0) { /* more bytes to be written */
+ intr_mask |= DW_IC_INTR_TX_EMPTY;
+ dev->status |= STATUS_WRITE_IN_PROGRESS;
+ } else
+ dev->status &= ~STATUS_WRITE_IN_PROGRESS;
+ writew(intr_mask, dev->base + DW_IC_INTR_MASK);
+}
+
+static void
+i2c_dw_read(struct i2c_adapter *adap)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+ struct i2c_msg *msgs = dev->msgs;
+ int num = dev->msgs_num;
+ u16 addr = msgs[dev->msg_read_idx].addr;
+ int rx_valid = readw(dev->base + DW_IC_RXFLR);
+
+ for (; dev->msg_read_idx < num; dev->msg_read_idx++) {
+ static int len;
+ static u8 *buf;
+
+ if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
+ continue;
+
+ /* different i2c client, reprogram the i2c adapter */
+ if (msgs[dev->msg_read_idx].addr != addr)
+ return;
+
+ if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
+ len = msgs[dev->msg_read_idx].len;
+ buf = msgs[dev->msg_read_idx].buf;
+ }
+
+ for (; len > 0 && rx_valid > 0; len--, rx_valid--)
+ *buf++ = readb(dev->base + DW_IC_DATA_CMD);
+
+ if (len > 0) {
+ dev->status |= STATUS_READ_IN_PROGRESS;
+ return;
+ } else
+ dev->status &= ~STATUS_READ_IN_PROGRESS;
+ }
+}
+
+/*
+ * Prepare controller for a transaction and call i2c_dw_xfer_msg
+ */
+static int
+i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+ int ret;
+
+ dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
+
+ mutex_lock(&dev->lock);
+
+ INIT_COMPLETION(dev->cmd_complete);
+ dev->msgs = msgs;
+ dev->msgs_num = num;
+ dev->cmd_err = 0;
+ dev->msg_write_idx = 0;
+ dev->msg_read_idx = 0;
+ dev->msg_err = 0;
+ dev->status = STATUS_IDLE;
+
+ ret = i2c_dw_wait_bus_not_busy(dev);
+ if (ret < 0)
+ goto done;
+
+ /* start the transfers */
+ i2c_dw_xfer_msg(adap);
+
+ /* wait for tx to complete */
+ ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
+ if (ret == 0) {
+ dev_err(dev->dev, "controller timed out\n");
+ i2c_dw_init(dev);
+ ret = -ETIMEDOUT;
+ goto done;
+ } else if (ret < 0)
+ goto done;
+
+ if (dev->msg_err) {
+ ret = dev->msg_err;
+ goto done;
+ }
+
+ /* no error */
+ if (likely(!dev->cmd_err)) {
+ /* read rx fifo, and disable the adapter */
+ do {
+ i2c_dw_read(adap);
+ } while (dev->status & STATUS_READ_IN_PROGRESS);
+ writeb(0, dev->base + DW_IC_ENABLE);
+ ret = num;
+ goto done;
+ }
+
+ /* We have an error */
+ if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
+ unsigned long abort_source = dev->abort_source;
+ int i;
+
+ for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) {
+ dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
+ }
+ }
+ ret = -EIO;
+
+done:
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
+static u32 i2c_dw_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
+}
+
+static void dw_i2c_pump_msg(unsigned long data)
+{
+ struct dw_i2c_dev *dev = (struct dw_i2c_dev *) data;
+ u16 intr_mask;
+
+ i2c_dw_read(&dev->adapter);
+ i2c_dw_xfer_msg(&dev->adapter);
+
+ intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
+ if (dev->status & STATUS_WRITE_IN_PROGRESS)
+ intr_mask |= DW_IC_INTR_TX_EMPTY;
+ writew(intr_mask, dev->base + DW_IC_INTR_MASK);
+}
+
+/*
+ * Interrupt service routine. This gets called whenever an I2C interrupt
+ * occurs.
+ */
+static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
+{
+ struct dw_i2c_dev *dev = dev_id;
+ u16 stat;
+
+ stat = readw(dev->base + DW_IC_INTR_STAT);
+ dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
+ if (stat & DW_IC_INTR_TX_ABRT) {
+ dev->abort_source = readw(dev->base + DW_IC_TX_ABRT_SOURCE);
+ dev->cmd_err |= DW_IC_ERR_TX_ABRT;
+ dev->status = STATUS_IDLE;
+ } else if (stat & DW_IC_INTR_TX_EMPTY)
+ tasklet_schedule(&dev->pump_msg);
+
+ readb(dev->base + DW_IC_CLR_INTR); /* clear interrupts */
+ writew(0, dev->base + DW_IC_INTR_MASK); /* disable interrupts */
+ if (stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
+ complete(&dev->cmd_complete);
+
+ return IRQ_HANDLED;
+}
+
+static struct i2c_algorithm i2c_dw_algo = {
+ .master_xfer = i2c_dw_xfer,
+ .functionality = i2c_dw_func,
+};
+
+static int dw_i2c_probe(struct platform_device *pdev)
+{
+ struct dw_i2c_dev *dev;
+ struct i2c_adapter *adap;
+ struct resource *mem, *irq, *ioarea;
+ int r;
+
+ /* NOTE: driver uses the static register mapping */
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!mem) {
+ dev_err(&pdev->dev, "no mem resource?\n");
+ return -ENODEV;
+ }
+
+ irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!irq) {
+ dev_err(&pdev->dev, "no irq resource?\n");
+ return -ENODEV;
+ }
+
+ ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
+ pdev->name);
+ if (!ioarea) {
+ dev_err(&pdev->dev, "I2C region already claimed\n");
+ return -EBUSY;
+ }
+
+ dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
+ if (!dev) {
+ r = -ENOMEM;
+ goto err_release_region;
+ }
+
+ init_completion(&dev->cmd_complete);
+ tasklet_init(&dev->pump_msg, dw_i2c_pump_msg, (unsigned long) dev);
+ mutex_init(&dev->lock);
+ dev->dev = get_device(&pdev->dev);
+ dev->irq = irq->start;
+ platform_set_drvdata(pdev, dev);
+
+ dev->clk = clk_get(&pdev->dev, "I2CCLK");
+ if (IS_ERR(dev->clk)) {
+ r = -ENODEV;
+ goto err_free_mem;
+ }
+ clk_enable(dev->clk);
+
+ dev->base = ioremap(mem->start, mem->end - mem->start + 1);
+ if (dev->base == NULL) {
+ dev_err(&pdev->dev, "failure mapping io resources\n");
+ r = -EBUSY;
+ goto err_unuse_clocks;
+ }
+ dev->tx_fifo_depth =
+ ((readl(dev->base + DW_IC_COMP_PARAM_1) & 0x00ff0000) >> 16) + 1;
+ dev->rx_fifo_depth =
+ ((readl(dev->base + DW_IC_COMP_PARAM_1) & 0x0000ff00) >> 8) + 1;
+ i2c_dw_init(dev);
+
+ writew(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
+ r = request_irq(dev->irq, i2c_dw_isr, 0, pdev->name, dev);
+ if (r) {
+ dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
+ goto err_iounmap;
+ }
+
+ adap = &dev->adapter;
+ i2c_set_adapdata(adap, dev);
+ adap->owner = THIS_MODULE;
+ adap->class = I2C_CLASS_HWMON;
+ strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
+ sizeof(adap->name));
+ adap->algo = &i2c_dw_algo;
+ adap->dev.parent = &pdev->dev;
+
+ adap->nr = pdev->id;
+ r = i2c_add_numbered_adapter(adap);
+ if (r) {
+ dev_err(&pdev->dev, "failure adding adapter\n");
+ goto err_free_irq;
+ }
+
+ return 0;
+
+err_free_irq:
+ free_irq(dev->irq, dev);
+err_iounmap:
+ iounmap(dev->base);
+err_unuse_clocks:
+ clk_disable(dev->clk);
+ clk_put(dev->clk);
+ dev->clk = NULL;
+err_free_mem:
+ platform_set_drvdata(pdev, NULL);
+ put_device(&pdev->dev);
+ kfree(dev);
+err_release_region:
+ release_mem_region(mem->start, (mem->end - mem->start) + 1);
+
+ return r;
+}
+
+static int dw_i2c_remove(struct platform_device *pdev)
+{
+ struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+ struct resource *mem;
+
+ platform_set_drvdata(pdev, NULL);
+ i2c_del_adapter(&dev->adapter);
+ put_device(&pdev->dev);
+
+ clk_disable(dev->clk);
+ clk_put(dev->clk);
+ dev->clk = NULL;
+
+ writeb(0, dev->base + DW_IC_ENABLE);
+ free_irq(dev->irq, dev);
+ kfree(dev);
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ release_mem_region(mem->start, (mem->end - mem->start) + 1);
+ return 0;
+}
+
+/* work with hotplug and coldplug */
+MODULE_ALIAS("platform:i2c_designware");
+
+static struct platform_driver dw_i2c_driver = {
+ .probe = dw_i2c_probe,
+ .remove = dw_i2c_remove,
+ .driver = {
+ .name = "i2c_designware",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init dw_i2c_init_driver(void)
+{
+ return platform_driver_register(&dw_i2c_driver);
+}
+module_init(dw_i2c_init_driver);
+
+static void __exit dw_i2c_exit_driver(void)
+{
+ platform_driver_unregister(&dw_i2c_driver);
+}
+module_exit(dw_i2c_exit_driver);
+
+MODULE_AUTHOR("Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>");
+MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
+MODULE_LICENSE("GPL");
--
1.6.2.4
^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
[not found] ` <1242725005-6431-1-git-send-email-baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
2009-05-26 21:39 ` Ben Dooks
@ 2009-05-27 19:23 ` Linus Walleij
[not found] ` <63386a3d0905271223k470bb89elbbb566b68c0d7cd7-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
1 sibling, 1 reply; 12+ messages in thread
From: Linus Walleij @ 2009-05-27 19:23 UTC (permalink / raw)
To: Baruch Siach; +Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA, Ben Dooks
Just some comments since I've been reading a lot of drivers lately...
2009/5/19 Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>:
>
> Signed-off-by: Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
> ---
> drivers/i2c/busses/Kconfig | 9 +
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-designware.c | 587 +++++++++++++++++++++++++++++++++++
> 3 files changed, 597 insertions(+), 0 deletions(-)
> create mode 100644 drivers/i2c/busses/i2c-designware.c
>
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index f1c6ca7..cef1567 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -326,6 +326,15 @@ config I2C_DAVINCI
> devices such as DaVinci NIC.
> For details please see http://www.ti.com/davinci
>
> +config I2C_DESIGNWARE
> + tristate "Synopsys DesignWare"
> + help
> + If you say yes to this option, support will be included for the
> + Synopsys DesignWare I2C adapter. Only master mode is supported.
> +
> + This driver can also be built as a module. If so, the module
> + will be called i2c-designware.
> +
> config I2C_GPIO
> tristate "GPIO-based bitbanging I2C"
> depends on GENERIC_GPIO
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index 776acb6..c2be11e 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -30,6 +30,7 @@ obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
> obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o
> obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
> obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o
> +obj-$(CONFIG_I2C_DESIGNWARE) += i2c-designware.o
> obj-$(CONFIG_I2C_GPIO) += i2c-gpio.o
> obj-$(CONFIG_I2C_HIGHLANDER) += i2c-highlander.o
> obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o
> diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c
> new file mode 100644
> index 0000000..0138fea
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-designware.c
> @@ -0,0 +1,587 @@
> +/*
> + * Synopsys Designware I2C adapter driver (master only).
> + *
> + * Based on the TI DAVINCI I2C adapter driver.
> + *
> + * Copyright (C) 2006 Texas Instruments.
> + * Copyright (C) 2007 MontaVista Software Inc.
> + * Copyright (C) 2009 Provigent Ltd.
> + *
> + * ----------------------------------------------------------------------------
> + *
> + * 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.
> + * ----------------------------------------------------------------------------
> + *
> + */
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/clk.h>
> +#include <linux/errno.h>
> +#include <linux/sched.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/io.h>
> +
> +/*
> + * Registers offset
> + */
> +#define DW_IC_CON 0x0
> +#define DW_IC_TAR 0x4
> +#define DW_IC_DATA_CMD 0x10
> +#define DW_IC_SS_SCL_HCNT 0x14
> +#define DW_IC_SS_SCL_LCNT 0x18
> +#define DW_IC_FS_SCL_HCNT 0x1c
> +#define DW_IC_FS_SCL_LCNT 0x20
> +#define DW_IC_INTR_STAT 0x2c
> +#define DW_IC_INTR_MASK 0x30
> +#define DW_IC_CLR_INTR 0x40
> +#define DW_IC_ENABLE 0x6c
> +#define DW_IC_STATUS 0x70
> +#define DW_IC_TXFLR 0x74
> +#define DW_IC_RXFLR 0x78
> +#define DW_IC_COMP_PARAM_1 0xf4
> +#define DW_IC_TX_ABRT_SOURCE 0x80
> +
> +#define DW_IC_CON_MASTER 0x1
> +#define DW_IC_CON_SPEED_STD 0x2
> +#define DW_IC_CON_SPEED_FAST 0x4
> +#define DW_IC_CON_10BITADDR_MASTER 0x10
> +#define DW_IC_CON_RESTART_EN 0x20
> +#define DW_IC_CON_SLAVE_DISABLE 0x40
> +
> +#define DW_IC_INTR_TX_EMPTY 0x10
> +#define DW_IC_INTR_TX_ABRT 0x40
> +#define DW_IC_INTR_STOP_DET 0x200
> +
> +#define DW_IC_STATUS_ACTIVITY 0x1
> +
> +#define DW_IC_ERR_TX_ABRT 0x1
> +
> +/*
> + * status codes
> + */
> +#define STATUS_IDLE 0x0
> +#define STATUS_WRITE_IN_PROGRESS 0x1
> +#define STATUS_READ_IN_PROGRESS 0x2
> +
> +/*
> + * hardware abort codes
> + *
> + * only expected abort codes are listed here
> + * refer to the datasheet for the full list
Write here that this is the bit number in register DW_IC_TX_ABRT_SOURCE
that's good to know!
Makes me curious why the rest of the codes are unexpected, usually
error paths handle the unexpected but hey, I can live with degrees
of unexpectedness..
> + */
> +#define ABRT_7B_ADDR_NOACK 0
> +#define ABRT_10ADDR1_NOACK 1
> +#define ABRT_10ADDR2_NOACK 2
> +#define ABRT_TXDATA_NOACK 3
> +#define ABRT_GCALL_NOACK 4
> +#define ABRT_GCALL_READ 5
> +#define ABRT_SBYTE_ACKDET 7
> +#define ABRT_SBYTE_NORSTRT 9
> +#define ABRT_10B_RD_NORSTRT 10
> +#define ARB_MASTER_DIS 11
> +#define ARB_LOST 12
> +
> +static char *abort_sources[] = {
> + [ABRT_7B_ADDR_NOACK] =
> + "slave address not acknowledged (7bit mode)",
> + [ABRT_10ADDR1_NOACK] =
> + "first address byte not acknowledged (10bit mode)",
> + [ABRT_10ADDR2_NOACK] =
> + "second address byte not acknowledged (10bit mode)",
> + [ABRT_TXDATA_NOACK] =
> + "data not acknowledged",
> + [ABRT_GCALL_NOACK] =
> + "no acknowledgement for a general call",
> + [ABRT_GCALL_READ] =
> + "read after general call",
> + [ABRT_SBYTE_ACKDET] =
> + "start byte acknowledged",
> + [ABRT_SBYTE_NORSTRT] =
> + "trying to send start byte when restart is disabled",
> + [ABRT_10B_RD_NORSTRT] =
> + "trying to read when restart is disabled (10bit mode)",
> + [ARB_MASTER_DIS] =
> + "trying to use disabled adapter",
> + [ARB_LOST] =
> + "lost arbitration",
> +};
> +
> +struct dw_i2c_dev {
> + struct device *dev;
> + void __iomem *base;
> + struct completion cmd_complete;
> + struct tasklet_struct pump_msg;
> + struct mutex lock;
> + struct clk *clk;
> + int cmd_err;
> + struct i2c_msg *msgs;
> + int msgs_num;
> + int msg_write_idx;
> + int msg_read_idx;
> + int msg_err;
> + unsigned int status;
> + u16 abort_source;
> + int irq;
> + struct i2c_adapter adapter;
> + unsigned int tx_fifo_depth;
> + unsigned int rx_fifo_depth;
> +};
> +
> +/*
> + * This functions configures I2C and enables I2C.
> + * This function is called during I2C init function.
> + */
> +static int i2c_dw_init(struct dw_i2c_dev *dev)
Can this be tagged with __init?
> +{
> + u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
> + u16 ic_con;
> +
> + /* Disable the adapter */
> + writeb(0, dev->base + DW_IC_ENABLE);
> +
> + /* set standard and fast speed deviders for high/low periods */
> + writew((input_clock_khz * 40 / 10000)+1, /* std speed high, 4us */
> + dev->base + DW_IC_SS_SCL_HCNT);
> + writew((input_clock_khz * 47 / 10000)+1, /* std speed low, 4.7us */
> + dev->base + DW_IC_SS_SCL_LCNT);
> + writew((input_clock_khz * 6 / 10000)+1, /* fast speed high, 0.6us */
> + dev->base + DW_IC_FS_SCL_HCNT);
> + writew((input_clock_khz * 13 / 10000)+1, /* fast speed low, 1.3us */
> + dev->base + DW_IC_FS_SCL_LCNT);
> +
> + /* configure the i2c master */
> + ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
> + DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
> + writew(ic_con, dev->base + DW_IC_CON);
> +
> + return 0;
> +}
> +
> +/*
> + * Waiting for bus not busy
> + */
> +static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
> +{
> + unsigned long timeout;
> +
> + timeout = jiffies + HZ;
Is this timeout really valid if this device is clocked differently than
the CPU, as indicated when supplying a clk? Well, should work...
> + while (readb(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
> + if (time_after(jiffies, timeout)) {
> + dev_warn(dev->dev,
> + "timeout waiting for bus ready\n");
> + return -ETIMEDOUT;
> + }
> + schedule_timeout(1);
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * Initiate low level master read/write transaction.
> + * This function is called from i2c_dw_xfer when starting a transfer.
> + * This function is also called from dw_i2c_pump_msg to continue a transfer
> + * that is longer than the size of the TX FIFO.
> + */
> +static void
> +i2c_dw_xfer_msg(struct i2c_adapter *adap)
> +{
> + struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
> + struct i2c_msg *msgs = dev->msgs;
> + int num = dev->msgs_num;
> + u16 ic_con, intr_mask;
> + int tx_valid_bytes = readb(dev->base + DW_IC_TXFLR);
> + int tx_limit = dev->tx_fifo_depth - tx_valid_bytes;
> + int rx_limit = dev->rx_fifo_depth - readb(dev->base + DW_IC_RXFLR)
> + - tx_valid_bytes;
> + static u16 buf_len = 0;
> + static u16 addr;
> +
> + if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
> + /* Disable the adapter */
> + writeb(0, dev->base + DW_IC_ENABLE);
> +
> + /* set the slave (target) address */
> + writew(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
> +
> + /* if the slave address is ten bit address, enable 10BITADDR */
> + ic_con = readw(dev->base + DW_IC_CON);
> + if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
> + ic_con |= DW_IC_CON_10BITADDR_MASTER;
> + else
> + ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
> + writew(ic_con, dev->base + DW_IC_CON);
> +
> + /* Enable the adapter */
> + writeb(1, dev->base + DW_IC_ENABLE);
> +
> + addr = msgs[dev->msg_write_idx].addr;
> + }
> +
> + for (; dev->msg_write_idx < num; dev->msg_write_idx++) {
> + static u8 *buf;
> +
> + /* if target address has changed, we need to
> + * reprogram the target address in the i2c
> + * adapter when we are done with this transfer
> + */
> + if (msgs[dev->msg_write_idx].addr != addr)
> + return;
> +
> + if (msgs[dev->msg_write_idx].len == 0) {
> + dev_err(dev->dev,
> + "%s: invalid message length\n", __func__);
> + dev->msg_err = -EINVAL;
> + return;
> + }
> +
> + if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
> + /* new i2c_msg */
> + buf = msgs[dev->msg_write_idx].buf;
> + buf_len = msgs[dev->msg_write_idx].len;
> + }
> +
> + for (; buf_len > 0 && tx_limit > 0 && rx_limit > 0; buf_len--)
> + if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
> + writew(0x100, dev->base + DW_IC_DATA_CMD);
> + rx_limit--; tx_limit--;
> + } else {
> + writew(*buf++, dev->base + DW_IC_DATA_CMD);
> + tx_limit--;
> + }
> + }
> +
> + intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
> + if (buf_len > 0) { /* more bytes to be written */
> + intr_mask |= DW_IC_INTR_TX_EMPTY;
> + dev->status |= STATUS_WRITE_IN_PROGRESS;
> + } else
> + dev->status &= ~STATUS_WRITE_IN_PROGRESS;
> + writew(intr_mask, dev->base + DW_IC_INTR_MASK);
> +}
> +
> +static void
> +i2c_dw_read(struct i2c_adapter *adap)
> +{
> + struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
> + struct i2c_msg *msgs = dev->msgs;
> + int num = dev->msgs_num;
> + u16 addr = msgs[dev->msg_read_idx].addr;
> + int rx_valid = readw(dev->base + DW_IC_RXFLR);
> +
> + for (; dev->msg_read_idx < num; dev->msg_read_idx++) {
> + static int len;
> + static u8 *buf;
> +
> + if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
> + continue;
> +
> + /* different i2c client, reprogram the i2c adapter */
> + if (msgs[dev->msg_read_idx].addr != addr)
> + return;
> +
> + if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
> + len = msgs[dev->msg_read_idx].len;
> + buf = msgs[dev->msg_read_idx].buf;
> + }
> +
> + for (; len > 0 && rx_valid > 0; len--, rx_valid--)
> + *buf++ = readb(dev->base + DW_IC_DATA_CMD);
> +
> + if (len > 0) {
> + dev->status |= STATUS_READ_IN_PROGRESS;
> + return;
> + } else
> + dev->status &= ~STATUS_READ_IN_PROGRESS;
> + }
> +}
> +
> +/*
> + * Prepare controller for a transaction and call i2c_dw_xfer_msg
> + */
> +static int
> +i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
> +{
> + struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
> + int ret;
> +
> + dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
> +
> + mutex_lock(&dev->lock);
> +
> + INIT_COMPLETION(dev->cmd_complete);
> + dev->msgs = msgs;
> + dev->msgs_num = num;
> + dev->cmd_err = 0;
> + dev->msg_write_idx = 0;
> + dev->msg_read_idx = 0;
> + dev->msg_err = 0;
> + dev->status = STATUS_IDLE;
> +
> + ret = i2c_dw_wait_bus_not_busy(dev);
> + if (ret < 0)
> + goto done;
> +
> + /* start the transfers */
> + i2c_dw_xfer_msg(adap);
> +
> + /* wait for tx to complete */
> + ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
> + if (ret == 0) {
> + dev_err(dev->dev, "controller timed out\n");
> + i2c_dw_init(dev);
> + ret = -ETIMEDOUT;
> + goto done;
> + } else if (ret < 0)
> + goto done;
> +
> + if (dev->msg_err) {
> + ret = dev->msg_err;
> + goto done;
> + }
> +
> + /* no error */
> + if (likely(!dev->cmd_err)) {
> + /* read rx fifo, and disable the adapter */
> + do {
> + i2c_dw_read(adap);
> + } while (dev->status & STATUS_READ_IN_PROGRESS);
> + writeb(0, dev->base + DW_IC_ENABLE);
> + ret = num;
> + goto done;
> + }
> +
> + /* We have an error */
> + if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
> + unsigned long abort_source = dev->abort_source;
> + int i;
> +
> + for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) {
> + dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
> + }
> + }
> + ret = -EIO;
> +
> +done:
> + mutex_unlock(&dev->lock);
> +
> + return ret;
> +}
> +
> +static u32 i2c_dw_func(struct i2c_adapter *adap)
> +{
> + return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
> +}
> +
> +static void dw_i2c_pump_msg(unsigned long data)
> +{
> + struct dw_i2c_dev *dev = (struct dw_i2c_dev *) data;
> + u16 intr_mask;
> +
> + i2c_dw_read(&dev->adapter);
> + i2c_dw_xfer_msg(&dev->adapter);
> +
> + intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
> + if (dev->status & STATUS_WRITE_IN_PROGRESS)
> + intr_mask |= DW_IC_INTR_TX_EMPTY;
> + writew(intr_mask, dev->base + DW_IC_INTR_MASK);
> +}
> +
> +/*
> + * Interrupt service routine. This gets called whenever an I2C interrupt
> + * occurs.
> + */
> +static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
> +{
> + struct dw_i2c_dev *dev = dev_id;
> + u16 stat;
> +
> + stat = readw(dev->base + DW_IC_INTR_STAT);
> + dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
> + if (stat & DW_IC_INTR_TX_ABRT) {
> + dev->abort_source = readw(dev->base + DW_IC_TX_ABRT_SOURCE);
> + dev->cmd_err |= DW_IC_ERR_TX_ABRT;
> + dev->status = STATUS_IDLE;
> + } else if (stat & DW_IC_INTR_TX_EMPTY)
> + tasklet_schedule(&dev->pump_msg);
> +
> + readb(dev->base + DW_IC_CLR_INTR); /* clear interrupts */
> + writew(0, dev->base + DW_IC_INTR_MASK); /* disable interrupts */
> + if (stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
> + complete(&dev->cmd_complete);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static struct i2c_algorithm i2c_dw_algo = {
> + .master_xfer = i2c_dw_xfer,
> + .functionality = i2c_dw_func,
> +};
> +
> +static int dw_i2c_probe(struct platform_device *pdev)
Can you tag this with __init?
> +{
> + struct dw_i2c_dev *dev;
> + struct i2c_adapter *adap;
> + struct resource *mem, *irq, *ioarea;
> + int r;
> +
> + /* NOTE: driver uses the static register mapping */
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!mem) {
> + dev_err(&pdev->dev, "no mem resource?\n");
> + return -ENODEV;
I've seen other drivers use -ENOENT which makes sense.
> + }
> +
> + irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> + if (!irq) {
> + dev_err(&pdev->dev, "no irq resource?\n");
> + return -ENODEV;
-ENOENT
> + }
> +
> + ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
Use resource_size(mem) instead of the last argument.
> + pdev->name);
> + if (!ioarea) {
> + dev_err(&pdev->dev, "I2C region already claimed\n");
> + return -EBUSY;
> + }
> +
> + dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
> + if (!dev) {
> + r = -ENOMEM;
> + goto err_release_region;
> + }
> +
> + init_completion(&dev->cmd_complete);
> + tasklet_init(&dev->pump_msg, dw_i2c_pump_msg, (unsigned long) dev);
> + mutex_init(&dev->lock);
> + dev->dev = get_device(&pdev->dev);
> + dev->irq = irq->start;
> + platform_set_drvdata(pdev, dev);
> +
> + dev->clk = clk_get(&pdev->dev, "I2CCLK");
> + if (IS_ERR(dev->clk)) {
> + r = -ENODEV;
> + goto err_free_mem;
> + }
> + clk_enable(dev->clk);
> +
> + dev->base = ioremap(mem->start, mem->end - mem->start + 1);
resource_size()
> + if (dev->base == NULL) {
> + dev_err(&pdev->dev, "failure mapping io resources\n");
> + r = -EBUSY;
> + goto err_unuse_clocks;
> + }
> + dev->tx_fifo_depth =
> + ((readl(dev->base + DW_IC_COMP_PARAM_1) & 0x00ff0000) >> 16) + 1;
> + dev->rx_fifo_depth =
> + ((readl(dev->base + DW_IC_COMP_PARAM_1) & 0x0000ff00) >> 8) + 1;
> + i2c_dw_init(dev);
> +
> + writew(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
> + r = request_irq(dev->irq, i2c_dw_isr, 0, pdev->name, dev);
> + if (r) {
> + dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
> + goto err_iounmap;
> + }
> +
> + adap = &dev->adapter;
> + i2c_set_adapdata(adap, dev);
> + adap->owner = THIS_MODULE;
> + adap->class = I2C_CLASS_HWMON;
> + strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
> + sizeof(adap->name));
> + adap->algo = &i2c_dw_algo;
> + adap->dev.parent = &pdev->dev;
> +
> + adap->nr = pdev->id;
> + r = i2c_add_numbered_adapter(adap);
> + if (r) {
> + dev_err(&pdev->dev, "failure adding adapter\n");
> + goto err_free_irq;
> + }
> +
> + return 0;
> +
> +err_free_irq:
> + free_irq(dev->irq, dev);
> +err_iounmap:
> + iounmap(dev->base);
> +err_unuse_clocks:
> + clk_disable(dev->clk);
> + clk_put(dev->clk);
> + dev->clk = NULL;
> +err_free_mem:
> + platform_set_drvdata(pdev, NULL);
> + put_device(&pdev->dev);
> + kfree(dev);
> +err_release_region:
> + release_mem_region(mem->start, (mem->end - mem->start) + 1);
resource_size()
> +
> + return r;
> +}
> +
> +static int dw_i2c_remove(struct platform_device *pdev)
Can you tag this with __exit?
> +{
> + struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
> + struct resource *mem;
> +
> + platform_set_drvdata(pdev, NULL);
> + i2c_del_adapter(&dev->adapter);
> + put_device(&pdev->dev);
> +
> + clk_disable(dev->clk);
> + clk_put(dev->clk);
> + dev->clk = NULL;
> +
> + writeb(0, dev->base + DW_IC_ENABLE);
> + free_irq(dev->irq, dev);
> + kfree(dev);
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + release_mem_region(mem->start, (mem->end - mem->start) + 1);
resource_size()
But I usually cache important resources in the driver private struct
(struct dw_i2c_dev in this case)
> + return 0;
> +}
> +
> +/* work with hotplug and coldplug */
> +MODULE_ALIAS("platform:i2c_designware");
> +
> +static struct platform_driver dw_i2c_driver = {
> + .probe = dw_i2c_probe,
Can you remove this and use platform_driver_probe() as detaile below instead?
> + .remove = dw_i2c_remove,
If the function can be tagges __exit, this can be tagged
__exit_p(dw_i2c_remove);
> + .driver = {
> + .name = "i2c_designware",
> + .owner = THIS_MODULE,
> + },
> +};
> +
> +static int __init dw_i2c_init_driver(void)
> +{
> + return platform_driver_register(&dw_i2c_driver);
return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
and remove the .probe field in the driver.
> +}
> +module_init(dw_i2c_init_driver);
> +
> +static void __exit dw_i2c_exit_driver(void)
> +{
> + platform_driver_unregister(&dw_i2c_driver);
> +}
> +module_exit(dw_i2c_exit_driver);
> +
> +MODULE_AUTHOR("Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>");
> +MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
> +MODULE_LICENSE("GPL");
> --
> 1.6.2.4
>
Yours,
Linus Walleij
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
[not found] ` <63386a3d0905271223k470bb89elbbb566b68c0d7cd7-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
@ 2009-05-28 4:10 ` Baruch Siach
2009-05-28 7:32 ` Linus Walleij
0 siblings, 1 reply; 12+ messages in thread
From: Baruch Siach @ 2009-05-28 4:10 UTC (permalink / raw)
To: Linus Walleij; +Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA, Ben Dooks
Hi Linus,
On Wed, May 27, 2009 at 09:23:22PM +0200, Linus Walleij wrote:
> Just some comments since I've been reading a lot of drivers lately...
Thank you very much.
> 2009/5/19 Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>:
> >
> > Signed-off-by: Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
> > ---
> > drivers/i2c/busses/Kconfig | 9 +
> > drivers/i2c/busses/Makefile | 1 +
> > drivers/i2c/busses/i2c-designware.c | 587 +++++++++++++++++++++++++++++++++++
> > 3 files changed, 597 insertions(+), 0 deletions(-)
> > create mode 100644 drivers/i2c/busses/i2c-designware.c
> >
> > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> > index f1c6ca7..cef1567 100644
> > --- a/drivers/i2c/busses/Kconfig
> > +++ b/drivers/i2c/busses/Kconfig
> > @@ -326,6 +326,15 @@ config I2C_DAVINCI
> > devices such as DaVinci NIC.
> > For details please see http://www.ti.com/davinci
> >
> > +config I2C_DESIGNWARE
> > + tristate "Synopsys DesignWare"
> > + help
> > + If you say yes to this option, support will be included for the
> > + Synopsys DesignWare I2C adapter. Only master mode is supported.
> > +
> > + This driver can also be built as a module. If so, the module
> > + will be called i2c-designware.
> > +
> > config I2C_GPIO
> > tristate "GPIO-based bitbanging I2C"
> > depends on GENERIC_GPIO
> > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> > index 776acb6..c2be11e 100644
> > --- a/drivers/i2c/busses/Makefile
> > +++ b/drivers/i2c/busses/Makefile
> > @@ -30,6 +30,7 @@ obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
> > obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o
> > obj-$(CONFIG_I2C_CPM) += i2c-cpm.o
> > obj-$(CONFIG_I2C_DAVINCI) += i2c-davinci.o
> > +obj-$(CONFIG_I2C_DESIGNWARE) += i2c-designware.o
> > obj-$(CONFIG_I2C_GPIO) += i2c-gpio.o
> > obj-$(CONFIG_I2C_HIGHLANDER) += i2c-highlander.o
> > obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o
> > diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c
> > new file mode 100644
> > index 0000000..0138fea
> > --- /dev/null
> > +++ b/drivers/i2c/busses/i2c-designware.c
> > @@ -0,0 +1,587 @@
> > +/*
> > + * Synopsys Designware I2C adapter driver (master only).
> > + *
> > + * Based on the TI DAVINCI I2C adapter driver.
> > + *
> > + * Copyright (C) 2006 Texas Instruments.
> > + * Copyright (C) 2007 MontaVista Software Inc.
> > + * Copyright (C) 2009 Provigent Ltd.
> > + *
> > + * ----------------------------------------------------------------------------
> > + *
> > + * 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.
> > + * ----------------------------------------------------------------------------
> > + *
> > + */
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/clk.h>
> > +#include <linux/errno.h>
> > +#include <linux/sched.h>
> > +#include <linux/err.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/io.h>
> > +
> > +/*
> > + * Registers offset
> > + */
> > +#define DW_IC_CON 0x0
> > +#define DW_IC_TAR 0x4
> > +#define DW_IC_DATA_CMD 0x10
> > +#define DW_IC_SS_SCL_HCNT 0x14
> > +#define DW_IC_SS_SCL_LCNT 0x18
> > +#define DW_IC_FS_SCL_HCNT 0x1c
> > +#define DW_IC_FS_SCL_LCNT 0x20
> > +#define DW_IC_INTR_STAT 0x2c
> > +#define DW_IC_INTR_MASK 0x30
> > +#define DW_IC_CLR_INTR 0x40
> > +#define DW_IC_ENABLE 0x6c
> > +#define DW_IC_STATUS 0x70
> > +#define DW_IC_TXFLR 0x74
> > +#define DW_IC_RXFLR 0x78
> > +#define DW_IC_COMP_PARAM_1 0xf4
> > +#define DW_IC_TX_ABRT_SOURCE 0x80
> > +
> > +#define DW_IC_CON_MASTER 0x1
> > +#define DW_IC_CON_SPEED_STD 0x2
> > +#define DW_IC_CON_SPEED_FAST 0x4
> > +#define DW_IC_CON_10BITADDR_MASTER 0x10
> > +#define DW_IC_CON_RESTART_EN 0x20
> > +#define DW_IC_CON_SLAVE_DISABLE 0x40
> > +
> > +#define DW_IC_INTR_TX_EMPTY 0x10
> > +#define DW_IC_INTR_TX_ABRT 0x40
> > +#define DW_IC_INTR_STOP_DET 0x200
> > +
> > +#define DW_IC_STATUS_ACTIVITY 0x1
> > +
> > +#define DW_IC_ERR_TX_ABRT 0x1
> > +
> > +/*
> > + * status codes
> > + */
> > +#define STATUS_IDLE 0x0
> > +#define STATUS_WRITE_IN_PROGRESS 0x1
> > +#define STATUS_READ_IN_PROGRESS 0x2
> > +
> > +/*
> > + * hardware abort codes
> > + *
> > + * only expected abort codes are listed here
> > + * refer to the datasheet for the full list
>
> Write here that this is the bit number in register DW_IC_TX_ABRT_SOURCE
> that's good to know!
OK.
> Makes me curious why the rest of the codes are unexpected, usually
> error paths handle the unexpected but hey, I can live with degrees
> of unexpectedness..
Aborts no. 6 and 8 are related to high seed which is not supported by this
driver. Aborts no. 13-15 are only relevant for hardware operating as slave,
which is not supported as well.
> > + */
> > +#define ABRT_7B_ADDR_NOACK 0
> > +#define ABRT_10ADDR1_NOACK 1
> > +#define ABRT_10ADDR2_NOACK 2
> > +#define ABRT_TXDATA_NOACK 3
> > +#define ABRT_GCALL_NOACK 4
> > +#define ABRT_GCALL_READ 5
> > +#define ABRT_SBYTE_ACKDET 7
> > +#define ABRT_SBYTE_NORSTRT 9
> > +#define ABRT_10B_RD_NORSTRT 10
> > +#define ARB_MASTER_DIS 11
> > +#define ARB_LOST 12
> > +
> > +static char *abort_sources[] = {
> > + [ABRT_7B_ADDR_NOACK] =
> > + "slave address not acknowledged (7bit mode)",
> > + [ABRT_10ADDR1_NOACK] =
> > + "first address byte not acknowledged (10bit mode)",
> > + [ABRT_10ADDR2_NOACK] =
> > + "second address byte not acknowledged (10bit mode)",
> > + [ABRT_TXDATA_NOACK] =
> > + "data not acknowledged",
> > + [ABRT_GCALL_NOACK] =
> > + "no acknowledgement for a general call",
> > + [ABRT_GCALL_READ] =
> > + "read after general call",
> > + [ABRT_SBYTE_ACKDET] =
> > + "start byte acknowledged",
> > + [ABRT_SBYTE_NORSTRT] =
> > + "trying to send start byte when restart is disabled",
> > + [ABRT_10B_RD_NORSTRT] =
> > + "trying to read when restart is disabled (10bit mode)",
> > + [ARB_MASTER_DIS] =
> > + "trying to use disabled adapter",
> > + [ARB_LOST] =
> > + "lost arbitration",
> > +};
> > +
> > +struct dw_i2c_dev {
> > + struct device *dev;
> > + void __iomem *base;
> > + struct completion cmd_complete;
> > + struct tasklet_struct pump_msg;
> > + struct mutex lock;
> > + struct clk *clk;
> > + int cmd_err;
> > + struct i2c_msg *msgs;
> > + int msgs_num;
> > + int msg_write_idx;
> > + int msg_read_idx;
> > + int msg_err;
> > + unsigned int status;
> > + u16 abort_source;
> > + int irq;
> > + struct i2c_adapter adapter;
> > + unsigned int tx_fifo_depth;
> > + unsigned int rx_fifo_depth;
> > +};
> > +
> > +/*
> > + * This functions configures I2C and enables I2C.
> > + * This function is called during I2C init function.
> > + */
> > +static int i2c_dw_init(struct dw_i2c_dev *dev)
>
> Can this be tagged with __init?
No. It's called from i2c_dw_xfer() at run time in case of timeout.
>
> > +{
> > + u32 input_clock_khz = clk_get_rate(dev->clk) / 1000;
> > + u16 ic_con;
> > +
> > + /* Disable the adapter */
> > + writeb(0, dev->base + DW_IC_ENABLE);
> > +
> > + /* set standard and fast speed deviders for high/low periods */
> > + writew((input_clock_khz * 40 / 10000)+1, /* std speed high, 4us */
> > + dev->base + DW_IC_SS_SCL_HCNT);
> > + writew((input_clock_khz * 47 / 10000)+1, /* std speed low, 4.7us */
> > + dev->base + DW_IC_SS_SCL_LCNT);
> > + writew((input_clock_khz * 6 / 10000)+1, /* fast speed high, 0.6us */
> > + dev->base + DW_IC_FS_SCL_HCNT);
> > + writew((input_clock_khz * 13 / 10000)+1, /* fast speed low, 1.3us */
> > + dev->base + DW_IC_FS_SCL_LCNT);
> > +
> > + /* configure the i2c master */
> > + ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
> > + DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
> > + writew(ic_con, dev->base + DW_IC_CON);
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Waiting for bus not busy
> > + */
> > +static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
> > +{
> > + unsigned long timeout;
> > +
> > + timeout = jiffies + HZ;
>
> Is this timeout really valid if this device is clocked differently than
> the CPU, as indicated when supplying a clk? Well, should work...
This really looks wrong. I'll look for some better way to do this.
> > + while (readb(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
> > + if (time_after(jiffies, timeout)) {
> > + dev_warn(dev->dev,
> > + "timeout waiting for bus ready\n");
> > + return -ETIMEDOUT;
> > + }
> > + schedule_timeout(1);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +/*
> > + * Initiate low level master read/write transaction.
> > + * This function is called from i2c_dw_xfer when starting a transfer.
> > + * This function is also called from dw_i2c_pump_msg to continue a transfer
> > + * that is longer than the size of the TX FIFO.
> > + */
> > +static void
> > +i2c_dw_xfer_msg(struct i2c_adapter *adap)
> > +{
> > + struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
> > + struct i2c_msg *msgs = dev->msgs;
> > + int num = dev->msgs_num;
> > + u16 ic_con, intr_mask;
> > + int tx_valid_bytes = readb(dev->base + DW_IC_TXFLR);
> > + int tx_limit = dev->tx_fifo_depth - tx_valid_bytes;
> > + int rx_limit = dev->rx_fifo_depth - readb(dev->base + DW_IC_RXFLR)
> > + - tx_valid_bytes;
> > + static u16 buf_len = 0;
> > + static u16 addr;
> > +
> > + if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
> > + /* Disable the adapter */
> > + writeb(0, dev->base + DW_IC_ENABLE);
> > +
> > + /* set the slave (target) address */
> > + writew(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR);
> > +
> > + /* if the slave address is ten bit address, enable 10BITADDR */
> > + ic_con = readw(dev->base + DW_IC_CON);
> > + if (msgs[dev->msg_write_idx].flags & I2C_M_TEN)
> > + ic_con |= DW_IC_CON_10BITADDR_MASTER;
> > + else
> > + ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
> > + writew(ic_con, dev->base + DW_IC_CON);
> > +
> > + /* Enable the adapter */
> > + writeb(1, dev->base + DW_IC_ENABLE);
> > +
> > + addr = msgs[dev->msg_write_idx].addr;
> > + }
> > +
> > + for (; dev->msg_write_idx < num; dev->msg_write_idx++) {
> > + static u8 *buf;
> > +
> > + /* if target address has changed, we need to
> > + * reprogram the target address in the i2c
> > + * adapter when we are done with this transfer
> > + */
> > + if (msgs[dev->msg_write_idx].addr != addr)
> > + return;
> > +
> > + if (msgs[dev->msg_write_idx].len == 0) {
> > + dev_err(dev->dev,
> > + "%s: invalid message length\n", __func__);
> > + dev->msg_err = -EINVAL;
> > + return;
> > + }
> > +
> > + if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) {
> > + /* new i2c_msg */
> > + buf = msgs[dev->msg_write_idx].buf;
> > + buf_len = msgs[dev->msg_write_idx].len;
> > + }
> > +
> > + for (; buf_len > 0 && tx_limit > 0 && rx_limit > 0; buf_len--)
> > + if (msgs[dev->msg_write_idx].flags & I2C_M_RD) {
> > + writew(0x100, dev->base + DW_IC_DATA_CMD);
> > + rx_limit--; tx_limit--;
> > + } else {
> > + writew(*buf++, dev->base + DW_IC_DATA_CMD);
> > + tx_limit--;
> > + }
> > + }
> > +
> > + intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
> > + if (buf_len > 0) { /* more bytes to be written */
> > + intr_mask |= DW_IC_INTR_TX_EMPTY;
> > + dev->status |= STATUS_WRITE_IN_PROGRESS;
> > + } else
> > + dev->status &= ~STATUS_WRITE_IN_PROGRESS;
> > + writew(intr_mask, dev->base + DW_IC_INTR_MASK);
> > +}
> > +
> > +static void
> > +i2c_dw_read(struct i2c_adapter *adap)
> > +{
> > + struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
> > + struct i2c_msg *msgs = dev->msgs;
> > + int num = dev->msgs_num;
> > + u16 addr = msgs[dev->msg_read_idx].addr;
> > + int rx_valid = readw(dev->base + DW_IC_RXFLR);
> > +
> > + for (; dev->msg_read_idx < num; dev->msg_read_idx++) {
> > + static int len;
> > + static u8 *buf;
> > +
> > + if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
> > + continue;
> > +
> > + /* different i2c client, reprogram the i2c adapter */
> > + if (msgs[dev->msg_read_idx].addr != addr)
> > + return;
> > +
> > + if (!(dev->status & STATUS_READ_IN_PROGRESS)) {
> > + len = msgs[dev->msg_read_idx].len;
> > + buf = msgs[dev->msg_read_idx].buf;
> > + }
> > +
> > + for (; len > 0 && rx_valid > 0; len--, rx_valid--)
> > + *buf++ = readb(dev->base + DW_IC_DATA_CMD);
> > +
> > + if (len > 0) {
> > + dev->status |= STATUS_READ_IN_PROGRESS;
> > + return;
> > + } else
> > + dev->status &= ~STATUS_READ_IN_PROGRESS;
> > + }
> > +}
> > +
> > +/*
> > + * Prepare controller for a transaction and call i2c_dw_xfer_msg
> > + */
> > +static int
> > +i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
> > +{
> > + struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
> > + int ret;
> > +
> > + dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
> > +
> > + mutex_lock(&dev->lock);
> > +
> > + INIT_COMPLETION(dev->cmd_complete);
> > + dev->msgs = msgs;
> > + dev->msgs_num = num;
> > + dev->cmd_err = 0;
> > + dev->msg_write_idx = 0;
> > + dev->msg_read_idx = 0;
> > + dev->msg_err = 0;
> > + dev->status = STATUS_IDLE;
> > +
> > + ret = i2c_dw_wait_bus_not_busy(dev);
> > + if (ret < 0)
> > + goto done;
> > +
> > + /* start the transfers */
> > + i2c_dw_xfer_msg(adap);
> > +
> > + /* wait for tx to complete */
> > + ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete, HZ);
> > + if (ret == 0) {
> > + dev_err(dev->dev, "controller timed out\n");
> > + i2c_dw_init(dev);
> > + ret = -ETIMEDOUT;
> > + goto done;
> > + } else if (ret < 0)
> > + goto done;
> > +
> > + if (dev->msg_err) {
> > + ret = dev->msg_err;
> > + goto done;
> > + }
> > +
> > + /* no error */
> > + if (likely(!dev->cmd_err)) {
> > + /* read rx fifo, and disable the adapter */
> > + do {
> > + i2c_dw_read(adap);
> > + } while (dev->status & STATUS_READ_IN_PROGRESS);
> > + writeb(0, dev->base + DW_IC_ENABLE);
> > + ret = num;
> > + goto done;
> > + }
> > +
> > + /* We have an error */
> > + if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
> > + unsigned long abort_source = dev->abort_source;
> > + int i;
> > +
> > + for_each_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) {
> > + dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]);
> > + }
> > + }
> > + ret = -EIO;
> > +
> > +done:
> > + mutex_unlock(&dev->lock);
> > +
> > + return ret;
> > +}
> > +
> > +static u32 i2c_dw_func(struct i2c_adapter *adap)
> > +{
> > + return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
> > +}
> > +
> > +static void dw_i2c_pump_msg(unsigned long data)
> > +{
> > + struct dw_i2c_dev *dev = (struct dw_i2c_dev *) data;
> > + u16 intr_mask;
> > +
> > + i2c_dw_read(&dev->adapter);
> > + i2c_dw_xfer_msg(&dev->adapter);
> > +
> > + intr_mask = DW_IC_INTR_STOP_DET | DW_IC_INTR_TX_ABRT;
> > + if (dev->status & STATUS_WRITE_IN_PROGRESS)
> > + intr_mask |= DW_IC_INTR_TX_EMPTY;
> > + writew(intr_mask, dev->base + DW_IC_INTR_MASK);
> > +}
> > +
> > +/*
> > + * Interrupt service routine. This gets called whenever an I2C interrupt
> > + * occurs.
> > + */
> > +static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
> > +{
> > + struct dw_i2c_dev *dev = dev_id;
> > + u16 stat;
> > +
> > + stat = readw(dev->base + DW_IC_INTR_STAT);
> > + dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat);
> > + if (stat & DW_IC_INTR_TX_ABRT) {
> > + dev->abort_source = readw(dev->base + DW_IC_TX_ABRT_SOURCE);
> > + dev->cmd_err |= DW_IC_ERR_TX_ABRT;
> > + dev->status = STATUS_IDLE;
> > + } else if (stat & DW_IC_INTR_TX_EMPTY)
> > + tasklet_schedule(&dev->pump_msg);
> > +
> > + readb(dev->base + DW_IC_CLR_INTR); /* clear interrupts */
> > + writew(0, dev->base + DW_IC_INTR_MASK); /* disable interrupts */
> > + if (stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET))
> > + complete(&dev->cmd_complete);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static struct i2c_algorithm i2c_dw_algo = {
> > + .master_xfer = i2c_dw_xfer,
> > + .functionality = i2c_dw_func,
> > +};
> > +
> > +static int dw_i2c_probe(struct platform_device *pdev)
>
> Can you tag this with __init?
OK. __devinit is probably better.
> > +{
> > + struct dw_i2c_dev *dev;
> > + struct i2c_adapter *adap;
> > + struct resource *mem, *irq, *ioarea;
> > + int r;
> > +
> > + /* NOTE: driver uses the static register mapping */
> > + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + if (!mem) {
> > + dev_err(&pdev->dev, "no mem resource?\n");
> > + return -ENODEV;
>
> I've seen other drivers use -ENOENT which makes sense.
OK.
> > + }
> > +
> > + irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
> > + if (!irq) {
> > + dev_err(&pdev->dev, "no irq resource?\n");
> > + return -ENODEV;
>
> -ENOENT
OK.
> > + }
> > +
> > + ioarea = request_mem_region(mem->start, (mem->end - mem->start) + 1,
>
> Use resource_size(mem) instead of the last argument.
OK.
> > + pdev->name);
> > + if (!ioarea) {
> > + dev_err(&pdev->dev, "I2C region already claimed\n");
> > + return -EBUSY;
> > + }
> > +
> > + dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
> > + if (!dev) {
> > + r = -ENOMEM;
> > + goto err_release_region;
> > + }
> > +
> > + init_completion(&dev->cmd_complete);
> > + tasklet_init(&dev->pump_msg, dw_i2c_pump_msg, (unsigned long) dev);
> > + mutex_init(&dev->lock);
> > + dev->dev = get_device(&pdev->dev);
> > + dev->irq = irq->start;
> > + platform_set_drvdata(pdev, dev);
> > +
> > + dev->clk = clk_get(&pdev->dev, "I2CCLK");
> > + if (IS_ERR(dev->clk)) {
> > + r = -ENODEV;
> > + goto err_free_mem;
> > + }
> > + clk_enable(dev->clk);
> > +
> > + dev->base = ioremap(mem->start, mem->end - mem->start + 1);
>
> resource_size()
OK.
> > + if (dev->base == NULL) {
> > + dev_err(&pdev->dev, "failure mapping io resources\n");
> > + r = -EBUSY;
> > + goto err_unuse_clocks;
> > + }
> > + dev->tx_fifo_depth =
> > + ((readl(dev->base + DW_IC_COMP_PARAM_1) & 0x00ff0000) >> 16) + 1;
> > + dev->rx_fifo_depth =
> > + ((readl(dev->base + DW_IC_COMP_PARAM_1) & 0x0000ff00) >> 8) + 1;
> > + i2c_dw_init(dev);
> > +
> > + writew(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */
> > + r = request_irq(dev->irq, i2c_dw_isr, 0, pdev->name, dev);
> > + if (r) {
> > + dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
> > + goto err_iounmap;
> > + }
> > +
> > + adap = &dev->adapter;
> > + i2c_set_adapdata(adap, dev);
> > + adap->owner = THIS_MODULE;
> > + adap->class = I2C_CLASS_HWMON;
> > + strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
> > + sizeof(adap->name));
> > + adap->algo = &i2c_dw_algo;
> > + adap->dev.parent = &pdev->dev;
> > +
> > + adap->nr = pdev->id;
> > + r = i2c_add_numbered_adapter(adap);
> > + if (r) {
> > + dev_err(&pdev->dev, "failure adding adapter\n");
> > + goto err_free_irq;
> > + }
> > +
> > + return 0;
> > +
> > +err_free_irq:
> > + free_irq(dev->irq, dev);
> > +err_iounmap:
> > + iounmap(dev->base);
> > +err_unuse_clocks:
> > + clk_disable(dev->clk);
> > + clk_put(dev->clk);
> > + dev->clk = NULL;
> > +err_free_mem:
> > + platform_set_drvdata(pdev, NULL);
> > + put_device(&pdev->dev);
> > + kfree(dev);
> > +err_release_region:
> > + release_mem_region(mem->start, (mem->end - mem->start) + 1);
>
> resource_size()
OK.
> > +
> > + return r;
> > +}
> > +
> > +static int dw_i2c_remove(struct platform_device *pdev)
>
> Can you tag this with __exit?
Or __devexit. OK.
> > +{
> > + struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
> > + struct resource *mem;
> > +
> > + platform_set_drvdata(pdev, NULL);
> > + i2c_del_adapter(&dev->adapter);
> > + put_device(&pdev->dev);
> > +
> > + clk_disable(dev->clk);
> > + clk_put(dev->clk);
> > + dev->clk = NULL;
> > +
> > + writeb(0, dev->base + DW_IC_ENABLE);
> > + free_irq(dev->irq, dev);
> > + kfree(dev);
> > +
> > + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > + release_mem_region(mem->start, (mem->end - mem->start) + 1);
>
> resource_size()
> But I usually cache important resources in the driver private struct
> (struct dw_i2c_dev in this case)
OK.
> > + return 0;
> > +}
> > +
> > +/* work with hotplug and coldplug */
> > +MODULE_ALIAS("platform:i2c_designware");
> > +
> > +static struct platform_driver dw_i2c_driver = {
> > + .probe = dw_i2c_probe,
>
> Can you remove this and use platform_driver_probe() as detaile below instead?
OK.
> > + .remove = dw_i2c_remove,
>
> If the function can be tagges __exit, this can be tagged
> __exit_p(dw_i2c_remove);
OK.
> > + .driver = {
> > + .name = "i2c_designware",
> > + .owner = THIS_MODULE,
> > + },
> > +};
> > +
> > +static int __init dw_i2c_init_driver(void)
> > +{
> > + return platform_driver_register(&dw_i2c_driver);
>
> return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
> and remove the .probe field in the driver.
OK.
> > +}
> > +module_init(dw_i2c_init_driver);
> > +
> > +static void __exit dw_i2c_exit_driver(void)
> > +{
> > + platform_driver_unregister(&dw_i2c_driver);
> > +}
> > +module_exit(dw_i2c_exit_driver);
> > +
> > +MODULE_AUTHOR("Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>");
> > +MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
> > +MODULE_LICENSE("GPL");
> > --
> > 1.6.2.4
> >
>
>
> Yours,
> Linus Walleij
baruch
--
~. .~ Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
- baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org - tel: +972.2.679.5364, http://www.tkos.co.il -
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
2009-05-28 4:10 ` Baruch Siach
@ 2009-05-28 7:32 ` Linus Walleij
[not found] ` <63386a3d0905280032x7f427213t2b9b027d5be2a472-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
0 siblings, 1 reply; 12+ messages in thread
From: Linus Walleij @ 2009-05-28 7:32 UTC (permalink / raw)
To: Baruch Siach; +Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA, Ben Dooks
2009/5/28 Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>:
>> > +static int dw_i2c_probe(struct platform_device *pdev)
>>
>> Can you tag this with __init?
>
> OK. __devinit is probably better.
(and same for exit)
Look in include/linux/init.h for the use of these macros. There
are many, many erroneous drivers in the kernel, and I think it
is mainly due to the fact that __devinit looks like it has something
to do with "devices", while it does not.
It should be named __hotpluginit or something so one can see
what it actually is.
I don't think any platform_device tagged with __devinit is
correct really, platform_device:s cannot be hotplugged that's
against the definition of a platform_device.
I should make more cleanup patches regarding this...
Linus
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
[not found] ` <63386a3d0905280032x7f427213t2b9b027d5be2a472-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
@ 2009-05-31 5:23 ` Baruch Siach
2009-05-31 18:47 ` Linus Walleij
2009-06-01 22:53 ` Ben Dooks
0 siblings, 2 replies; 12+ messages in thread
From: Baruch Siach @ 2009-05-31 5:23 UTC (permalink / raw)
To: Linus Walleij; +Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA, Ben Dooks
Hi Linus,
On Thu, May 28, 2009 at 09:32:37AM +0200, Linus Walleij wrote:
> 2009/5/28 Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>:
>
> >> > +static int dw_i2c_probe(struct platform_device *pdev)
> >>
> >> Can you tag this with __init?
> >
> > OK. __devinit is probably better.
>
> I don't think any platform_device tagged with __devinit is
> correct really, platform_device:s cannot be hotplugged that's
> against the definition of a platform_device.
Doesn't this __devinit have something to do with the ability to compile the
driver as a module (as is the case here)? See for example
drivers/watchdog/omap_wdt.c and commit
0e3912c75f42986c17d955542247bf04c6eef738
> I should make more cleanup patches regarding this...
baruch
--
~. .~ Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
- baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org - tel: +972.2.679.5364, http://www.tkos.co.il -
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
2009-05-31 5:23 ` Baruch Siach
@ 2009-05-31 18:47 ` Linus Walleij
[not found] ` <63386a3d0905311147h5a92bb3cy6659db914acd476e-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-01 22:53 ` Ben Dooks
1 sibling, 1 reply; 12+ messages in thread
From: Linus Walleij @ 2009-05-31 18:47 UTC (permalink / raw)
To: Baruch Siach; +Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA, Ben Dooks
2009/5/31 Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>:
> On Thu, May 28, 2009 at 09:32:37AM +0200, Linus Walleij wrote:
>> 2009/5/28 Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>:
>>
>> >> > +static int dw_i2c_probe(struct platform_device *pdev)
>> >>
>> >> Can you tag this with __init?
>> >
>> > OK. __devinit is probably better.
>>
>> I don't think any platform_device tagged with __devinit is
>> correct really, platform_device:s cannot be hotplugged that's
>> against the definition of a platform_device.
>
> Doesn't this __devinit have something to do with the ability to compile the
> driver as a module (as is the case here)? See for example
> drivers/watchdog/omap_wdt.c and commit
> 0e3912c75f42986c17d955542247bf04c6eef738
In that case I doubt that even module_init() could be __init, as it is.
The linkage handling of these symbols is defined in:
include/asm-generic/vmlinux.lds.h
As you can see:
#ifdef CONFIG_HOTPLUG
#define DEV_KEEP(sec) *(.dev##sec)
#define DEV_DISCARD(sec)
#else
#define DEV_KEEP(sec)
#define DEV_DISCARD(sec) *(.dev##sec)
#endif
Further down the file you can see how this is handled in different
kinds of symbols. It is kept if CONFIG_HOTPLUG is set, it is moved
into the DATA_DATA section and kept in memory (so that it can be
reused when devices are plugged/unplugged) else it is discarded
after init.
In practice this means that if you device is _NOT_ hot-pluggable, the
kernel will still nevertheless keep all the code in __devinit and
__devexit around which means that __devinit code cannot be
free:ed after init and it increases the footprint of your kernel for no
good reason.
Linus
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
[not found] ` <63386a3d0905311147h5a92bb3cy6659db914acd476e-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
@ 2009-06-01 3:43 ` Baruch Siach
0 siblings, 0 replies; 12+ messages in thread
From: Baruch Siach @ 2009-06-01 3:43 UTC (permalink / raw)
To: Linus Walleij; +Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA, Ben Dooks
Hi Linus,
On Sun, May 31, 2009 at 08:47:31PM +0200, Linus Walleij wrote:
> 2009/5/31 Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>:
> > On Thu, May 28, 2009 at 09:32:37AM +0200, Linus Walleij wrote:
> >> 2009/5/28 Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>:
> >>
> >> >> > +static int dw_i2c_probe(struct platform_device *pdev)
> >> >>
> >> >> Can you tag this with __init?
> >> >
> >> > OK. __devinit is probably better.
> >>
> >> I don't think any platform_device tagged with __devinit is
> >> correct really, platform_device:s cannot be hotplugged that's
> >> against the definition of a platform_device.
> >
> > Doesn't this __devinit have something to do with the ability to compile the
> > driver as a module (as is the case here)? See for example
> > drivers/watchdog/omap_wdt.c and commit
> > 0e3912c75f42986c17d955542247bf04c6eef738
>
> ...
>
> In practice this means that if you device is _NOT_ hot-pluggable, the
> kernel will still nevertheless keep all the code in __devinit and
> __devexit around which means that __devinit code cannot be
> free:ed after init and it increases the footprint of your kernel for no
> good reason.
Thanks for your detailed explanation. I'll go for __init then.
baruch
--
~. .~ Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
- baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org - tel: +972.2.679.5364, http://www.tkos.co.il -
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
2009-05-31 5:23 ` Baruch Siach
2009-05-31 18:47 ` Linus Walleij
@ 2009-06-01 22:53 ` Ben Dooks
[not found] ` <20090601225354.GB18453-elnMNo+KYs3pIgCt6eIbzw@public.gmane.org>
1 sibling, 1 reply; 12+ messages in thread
From: Ben Dooks @ 2009-06-01 22:53 UTC (permalink / raw)
To: Baruch Siach; +Cc: Linus Walleij, linux-i2c-u79uwXL29TY76Z2rM5mHXA, Ben Dooks
On Sun, May 31, 2009 at 08:23:45AM +0300, Baruch Siach wrote:
> Hi Linus,
>
> On Thu, May 28, 2009 at 09:32:37AM +0200, Linus Walleij wrote:
> > 2009/5/28 Baruch Siach <baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>:
> >
> > >> > +static int dw_i2c_probe(struct platform_device *pdev)
> > >>
> > >> Can you tag this with __init?
> > >
> > > OK. __devinit is probably better.
> >
> > I don't think any platform_device tagged with __devinit is
> > correct really, platform_device:s cannot be hotplugged that's
> > against the definition of a platform_device.
I disagree, just beucase they aren't in general doesn't mean they
cannot be. I have been looking at an implementation which uses
hotplug to generate devices from a board description file.
It also makes life difficult if you want to unbind/bind device via
sysfs. basically, __devinit and __devexit, are in my view the correct
things to use here.
> Doesn't this __devinit have something to do with the ability to compile the
> driver as a module (as is the case here)? See for example
> drivers/watchdog/omap_wdt.c and commit
> 0e3912c75f42986c17d955542247bf04c6eef738
This is an example where __devinit/_devexit are being used proplerly.
> > I should make more cleanup patches regarding this...
>
> baruch
>
> --
> ~. .~ Tk Open Systems
> =}------------------------------------------------ooO--U--Ooo------------{=
> - baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org - tel: +972.2.679.5364, http://www.tkos.co.il -
> --
> To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
> the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)
'a smiley only costs 4 bytes'
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
[not found] ` <20090601225354.GB18453-elnMNo+KYs3pIgCt6eIbzw@public.gmane.org>
@ 2009-06-02 6:57 ` Linus Walleij
0 siblings, 0 replies; 12+ messages in thread
From: Linus Walleij @ 2009-06-02 6:57 UTC (permalink / raw)
To: Ben Dooks; +Cc: Baruch Siach, linux-i2c-u79uwXL29TY76Z2rM5mHXA
2009/6/2 Ben Dooks <ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org>:
>> > I don't think any platform_device tagged with __devinit is
>> > correct really, platform_device:s cannot be hotplugged that's
>> > against the definition of a platform_device.
>
> I disagree, just beucase they aren't in general doesn't mean they
> cannot be. I have been looking at an implementation which uses
> hotplug to generate devices from a board description file.
OK I stand corrected!
Linus Walleij
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] i2c: driver for the Synopsys DesignWare I2C controller
[not found] ` <1243398392-1516-1-git-send-email-baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
@ 2009-06-13 9:28 ` Ben Dooks
0 siblings, 0 replies; 12+ messages in thread
From: Ben Dooks @ 2009-06-13 9:28 UTC (permalink / raw)
To: Baruch Siach; +Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA, Ben Dooks
Notes:
1) failed to fix resource_size()
2) No explanation over use of static in loop
Please sort these out and post a new patch.
--
Ben (ben-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, http://www.fluff.org/)
'a smiley only costs 4 bytes'
^ permalink raw reply [flat|nested] 12+ messages in thread
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2009-05-19 9:23 [PATCH] i2c: driver for the Synopsys DesignWare I2C controller Baruch Siach
[not found] ` <1242725005-6431-1-git-send-email-baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
2009-05-26 21:39 ` Ben Dooks
[not found] ` <20090526213917.GH23114-elnMNo+KYs3pIgCt6eIbzw@public.gmane.org>
2009-05-27 4:26 ` Baruch Siach
[not found] ` <1243398392-1516-1-git-send-email-baruch-NswTu9S1W3P6gbPvEgmw2w@public.gmane.org>
2009-06-13 9:28 ` Ben Dooks
2009-05-27 19:23 ` Linus Walleij
[not found] ` <63386a3d0905271223k470bb89elbbb566b68c0d7cd7-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-05-28 4:10 ` Baruch Siach
2009-05-28 7:32 ` Linus Walleij
[not found] ` <63386a3d0905280032x7f427213t2b9b027d5be2a472-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-05-31 5:23 ` Baruch Siach
2009-05-31 18:47 ` Linus Walleij
[not found] ` <63386a3d0905311147h5a92bb3cy6659db914acd476e-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2009-06-01 3:43 ` Baruch Siach
2009-06-01 22:53 ` Ben Dooks
[not found] ` <20090601225354.GB18453-elnMNo+KYs3pIgCt6eIbzw@public.gmane.org>
2009-06-02 6:57 ` Linus Walleij
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