diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware.c | 624 |
1 files changed, 0 insertions, 624 deletions
diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c deleted file mode 100644 index b444762e9b9..00000000000 --- a/drivers/i2c/busses/i2c-designware.c +++ /dev/null @@ -1,624 +0,0 @@ -/* - * 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 - -#define TIMEOUT 20 /* ms */ - -/* - * hardware abort codes from the DW_IC_TX_ABRT_SOURCE register - * - * 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 - private i2c-designware data - * @dev: driver model device node - * @base: IO registers pointer - * @cmd_complete: tx completion indicator - * @pump_msg: continue in progress transfers - * @lock: protect this struct and IO registers - * @clk: input reference clock - * @cmd_err: run time hadware error code - * @msgs: points to an array of messages currently being transfered - * @msgs_num: the number of elements in msgs - * @msg_write_idx: the element index of the current tx message in the msgs - * array - * @tx_buf_len: the length of the current tx buffer - * @tx_buf: the current tx buffer - * @msg_read_idx: the element index of the current rx message in the msgs - * array - * @rx_buf_len: the length of the current rx buffer - * @rx_buf: the current rx buffer - * @msg_err: error status of the current transfer - * @status: i2c master status, one of STATUS_* - * @abort_source: copy of the TX_ABRT_SOURCE register - * @irq: interrupt number for the i2c master - * @adapter: i2c subsystem adapter node - * @tx_fifo_depth: depth of the hardware tx fifo - * @rx_fifo_depth: depth of the hardware rx fifo - */ -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; - u16 tx_buf_len; - u8 *tx_buf; - int msg_read_idx; - u16 rx_buf_len; - u8 *rx_buf; - 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; -}; - -/** - * i2c_dw_init() - initialize the designware i2c master hardware - * @dev: device private data - * - * This functions configures and enables the I2C master. - * This function is called during I2C init function, and in case of timeout at - * run time. - */ -static void 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); -} - -/* - * Waiting for bus not busy - */ -static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev) -{ - int timeout = TIMEOUT; - - while (readb(dev->base + DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) { - if (timeout <= 0) { - dev_warn(dev->dev, "timeout waiting for bus ready\n"); - return -ETIMEDOUT; - } - timeout--; - mdelay(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_limit = dev->tx_fifo_depth - readb(dev->base + DW_IC_TXFLR); - int rx_limit = dev->rx_fifo_depth - readb(dev->base + DW_IC_RXFLR); - u16 addr = msgs[dev->msg_write_idx].addr; - u16 buf_len = dev->tx_buf_len; - - 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); - } - - for (; dev->msg_write_idx < num; dev->msg_write_idx++) { - /* 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 */ - dev->tx_buf = msgs[dev->msg_write_idx].buf; - buf_len = msgs[dev->msg_write_idx].len; - } - - while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) { - if (msgs[dev->msg_write_idx].flags & I2C_M_RD) { - writew(0x100, dev->base + DW_IC_DATA_CMD); - rx_limit--; - } else - writew(*(dev->tx_buf++), - dev->base + DW_IC_DATA_CMD); - tx_limit--; buf_len--; - } - } - - 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); - - dev->tx_buf_len = buf_len; -} - -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++) { - u16 len; - 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; - } else { - len = dev->rx_buf_len; - buf = dev->rx_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; - dev->rx_buf_len = len; - dev->rx_buf = buf; - 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 __devinit 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 -EINVAL; - } - - irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); - if (!irq) { - dev_err(&pdev->dev, "no irq resource?\n"); - return -EINVAL; - } - - ioarea = request_mem_region(mem->start, resource_size(mem), - 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, NULL); - if (IS_ERR(dev->clk)) { - r = -ENODEV; - goto err_free_mem; - } - clk_enable(dev->clk); - - dev->base = ioremap(mem->start, resource_size(mem)); - if (dev->base == NULL) { - dev_err(&pdev->dev, "failure mapping io resources\n"); - r = -EBUSY; - goto err_unuse_clocks; - } - { - u32 param1 = readl(dev->base + DW_IC_COMP_PARAM_1); - - dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1; - dev->rx_fifo_depth = ((param1 >> 8) & 0xff) + 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, resource_size(mem)); - - return r; -} - -static int __devexit 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, resource_size(mem)); - return 0; -} - -/* work with hotplug and coldplug */ -MODULE_ALIAS("platform:i2c_designware"); - -static struct platform_driver dw_i2c_driver = { - .remove = __devexit_p(dw_i2c_remove), - .driver = { - .name = "i2c_designware", - .owner = THIS_MODULE, - }, -}; - -static int __init dw_i2c_init_driver(void) -{ - return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe); -} -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@tkos.co.il>"); -MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter"); -MODULE_LICENSE("GPL"); |