diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware.c')
-rw-r--r-- | drivers/i2c/busses/i2c-designware.c | 847 |
1 files changed, 0 insertions, 847 deletions
diff --git a/drivers/i2c/busses/i2c-designware.c b/drivers/i2c/busses/i2c-designware.c deleted file mode 100644 index b7a51c4..0000000 --- a/drivers/i2c/busses/i2c-designware.c +++ /dev/null @@ -1,847 +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> -#include <linux/slab.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_RAW_INTR_STAT 0x34 -#define DW_IC_RX_TL 0x38 -#define DW_IC_TX_TL 0x3c -#define DW_IC_CLR_INTR 0x40 -#define DW_IC_CLR_RX_UNDER 0x44 -#define DW_IC_CLR_RX_OVER 0x48 -#define DW_IC_CLR_TX_OVER 0x4c -#define DW_IC_CLR_RD_REQ 0x50 -#define DW_IC_CLR_TX_ABRT 0x54 -#define DW_IC_CLR_RX_DONE 0x58 -#define DW_IC_CLR_ACTIVITY 0x5c -#define DW_IC_CLR_STOP_DET 0x60 -#define DW_IC_CLR_START_DET 0x64 -#define DW_IC_CLR_GEN_CALL 0x68 -#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_RX_UNDER 0x001 -#define DW_IC_INTR_RX_OVER 0x002 -#define DW_IC_INTR_RX_FULL 0x004 -#define DW_IC_INTR_TX_OVER 0x008 -#define DW_IC_INTR_TX_EMPTY 0x010 -#define DW_IC_INTR_RD_REQ 0x020 -#define DW_IC_INTR_TX_ABRT 0x040 -#define DW_IC_INTR_RX_DONE 0x080 -#define DW_IC_INTR_ACTIVITY 0x100 -#define DW_IC_INTR_STOP_DET 0x200 -#define DW_IC_INTR_START_DET 0x400 -#define DW_IC_INTR_GEN_CALL 0x800 - -#define DW_IC_INTR_DEFAULT_MASK (DW_IC_INTR_RX_FULL | \ - DW_IC_INTR_TX_EMPTY | \ - DW_IC_INTR_TX_ABRT | \ - DW_IC_INTR_STOP_DET) - -#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 ABRT_MASTER_DIS 11 -#define ARB_LOST 12 - -#define DW_IC_TX_ABRT_7B_ADDR_NOACK (1UL << ABRT_7B_ADDR_NOACK) -#define DW_IC_TX_ABRT_10ADDR1_NOACK (1UL << ABRT_10ADDR1_NOACK) -#define DW_IC_TX_ABRT_10ADDR2_NOACK (1UL << ABRT_10ADDR2_NOACK) -#define DW_IC_TX_ABRT_TXDATA_NOACK (1UL << ABRT_TXDATA_NOACK) -#define DW_IC_TX_ABRT_GCALL_NOACK (1UL << ABRT_GCALL_NOACK) -#define DW_IC_TX_ABRT_GCALL_READ (1UL << ABRT_GCALL_READ) -#define DW_IC_TX_ABRT_SBYTE_ACKDET (1UL << ABRT_SBYTE_ACKDET) -#define DW_IC_TX_ABRT_SBYTE_NORSTRT (1UL << ABRT_SBYTE_NORSTRT) -#define DW_IC_TX_ABRT_10B_RD_NORSTRT (1UL << ABRT_10B_RD_NORSTRT) -#define DW_IC_TX_ABRT_MASTER_DIS (1UL << ABRT_MASTER_DIS) -#define DW_IC_TX_ARB_LOST (1UL << ARB_LOST) - -#define DW_IC_TX_ABRT_NOACK (DW_IC_TX_ABRT_7B_ADDR_NOACK | \ - DW_IC_TX_ABRT_10ADDR1_NOACK | \ - DW_IC_TX_ABRT_10ADDR2_NOACK | \ - DW_IC_TX_ABRT_TXDATA_NOACK | \ - DW_IC_TX_ABRT_GCALL_NOACK) - -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)", - [ABRT_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 - * @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 transferred - * @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 mutex lock; - struct clk *clk; - int cmd_err; - struct i2c_msg *msgs; - int msgs_num; - int msg_write_idx; - u32 tx_buf_len; - u8 *tx_buf; - int msg_read_idx; - u32 rx_buf_len; - u8 *rx_buf; - int msg_err; - unsigned int status; - u32 abort_source; - int irq; - struct i2c_adapter adapter; - unsigned int tx_fifo_depth; - unsigned int rx_fifo_depth; -}; - -static u32 -i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset) -{ - /* - * DesignWare I2C core doesn't seem to have solid strategy to meet - * the tHD;STA timing spec. Configuring _HCNT based on tHIGH spec - * will result in violation of the tHD;STA spec. - */ - if (cond) - /* - * Conditional expression: - * - * IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH - * - * This is based on the DW manuals, and represents an ideal - * configuration. The resulting I2C bus speed will be - * faster than any of the others. - * - * If your hardware is free from tHD;STA issue, try this one. - */ - return (ic_clk * tSYMBOL + 5000) / 10000 - 8 + offset; - else - /* - * Conditional expression: - * - * IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf) - * - * This is just experimental rule; the tHD;STA period turned - * out to be proportinal to (_HCNT + 3). With this setting, - * we could meet both tHIGH and tHD;STA timing specs. - * - * If unsure, you'd better to take this alternative. - * - * The reason why we need to take into account "tf" here, - * is the same as described in i2c_dw_scl_lcnt(). - */ - return (ic_clk * (tSYMBOL + tf) + 5000) / 10000 - 3 + offset; -} - -static u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset) -{ - /* - * Conditional expression: - * - * IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf) - * - * DW I2C core starts counting the SCL CNTs for the LOW period - * of the SCL clock (tLOW) as soon as it pulls the SCL line. - * In order to meet the tLOW timing spec, we need to take into - * account the fall time of SCL signal (tf). Default tf value - * should be 0.3 us, for safety. - */ - return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset; -} - -/** - * 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; - u32 ic_con, hcnt, lcnt; - - /* Disable the adapter */ - writel(0, dev->base + DW_IC_ENABLE); - - /* set standard and fast speed deviders for high/low periods */ - - /* Standard-mode */ - hcnt = i2c_dw_scl_hcnt(input_clock_khz, - 40, /* tHD;STA = tHIGH = 4.0 us */ - 3, /* tf = 0.3 us */ - 0, /* 0: DW default, 1: Ideal */ - 0); /* No offset */ - lcnt = i2c_dw_scl_lcnt(input_clock_khz, - 47, /* tLOW = 4.7 us */ - 3, /* tf = 0.3 us */ - 0); /* No offset */ - writel(hcnt, dev->base + DW_IC_SS_SCL_HCNT); - writel(lcnt, dev->base + DW_IC_SS_SCL_LCNT); - dev_dbg(dev->dev, "Standard-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); - - /* Fast-mode */ - hcnt = i2c_dw_scl_hcnt(input_clock_khz, - 6, /* tHD;STA = tHIGH = 0.6 us */ - 3, /* tf = 0.3 us */ - 0, /* 0: DW default, 1: Ideal */ - 0); /* No offset */ - lcnt = i2c_dw_scl_lcnt(input_clock_khz, - 13, /* tLOW = 1.3 us */ - 3, /* tf = 0.3 us */ - 0); /* No offset */ - writel(hcnt, dev->base + DW_IC_FS_SCL_HCNT); - writel(lcnt, dev->base + DW_IC_FS_SCL_LCNT); - dev_dbg(dev->dev, "Fast-mode HCNT:LCNT = %d:%d\n", hcnt, lcnt); - - /* Configure Tx/Rx FIFO threshold levels */ - writel(dev->tx_fifo_depth - 1, dev->base + DW_IC_TX_TL); - writel(0, dev->base + DW_IC_RX_TL); - - /* 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; - writel(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 (readl(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; -} - -static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) -{ - struct i2c_msg *msgs = dev->msgs; - u32 ic_con; - - /* Disable the adapter */ - writel(0, dev->base + DW_IC_ENABLE); - - /* set the slave (target) address */ - writel(msgs[dev->msg_write_idx].addr, dev->base + DW_IC_TAR); - - /* if the slave address is ten bit address, enable 10BITADDR */ - ic_con = readl(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; - writel(ic_con, dev->base + DW_IC_CON); - - /* Enable the adapter */ - writel(1, dev->base + DW_IC_ENABLE); - - /* Enable interrupts */ - writel(DW_IC_INTR_DEFAULT_MASK, dev->base + DW_IC_INTR_MASK); -} - -/* - * Initiate (and continue) low level master read/write transaction. - * This function is only called from i2c_dw_isr, and pumping i2c_msg - * messages into the tx buffer. Even if the size of i2c_msg data is - * longer than the size of the tx buffer, it handles everything. - */ -static void -i2c_dw_xfer_msg(struct dw_i2c_dev *dev) -{ - struct i2c_msg *msgs = dev->msgs; - u32 intr_mask; - int tx_limit, rx_limit; - u32 addr = msgs[dev->msg_write_idx].addr; - u32 buf_len = dev->tx_buf_len; - u8 *buf = dev->tx_buf;; - - intr_mask = DW_IC_INTR_DEFAULT_MASK; - - for (; dev->msg_write_idx < dev->msgs_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) { - dev_err(dev->dev, - "%s: invalid target address\n", __func__); - dev->msg_err = -EINVAL; - break; - } - - if (msgs[dev->msg_write_idx].len == 0) { - dev_err(dev->dev, - "%s: invalid message length\n", __func__); - dev->msg_err = -EINVAL; - break; - } - - 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; - } - - tx_limit = dev->tx_fifo_depth - readl(dev->base + DW_IC_TXFLR); - rx_limit = dev->rx_fifo_depth - readl(dev->base + DW_IC_RXFLR); - - while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) { - if (msgs[dev->msg_write_idx].flags & I2C_M_RD) { - writel(0x100, dev->base + DW_IC_DATA_CMD); - rx_limit--; - } else - writel(*buf++, dev->base + DW_IC_DATA_CMD); - tx_limit--; buf_len--; - } - - dev->tx_buf = buf; - dev->tx_buf_len = buf_len; - - if (buf_len > 0) { - /* more bytes to be written */ - dev->status |= STATUS_WRITE_IN_PROGRESS; - break; - } else - dev->status &= ~STATUS_WRITE_IN_PROGRESS; - } - - /* - * If i2c_msg index search is completed, we don't need TX_EMPTY - * interrupt any more. - */ - if (dev->msg_write_idx == dev->msgs_num) - intr_mask &= ~DW_IC_INTR_TX_EMPTY; - - if (dev->msg_err) - intr_mask = 0; - - writel(intr_mask, dev->base + DW_IC_INTR_MASK); -} - -static void -i2c_dw_read(struct dw_i2c_dev *dev) -{ - struct i2c_msg *msgs = dev->msgs; - int rx_valid; - - for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) { - u32 len; - u8 *buf; - - if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD)) - continue; - - 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; - } - - rx_valid = readl(dev->base + DW_IC_RXFLR); - - for (; len > 0 && rx_valid > 0; len--, rx_valid--) - *buf++ = readl(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; - } -} - -static int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev) -{ - unsigned long abort_source = dev->abort_source; - int i; - - if (abort_source & DW_IC_TX_ABRT_NOACK) { - for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) - dev_dbg(dev->dev, - "%s: %s\n", __func__, abort_sources[i]); - return -EREMOTEIO; - } - - for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources)) - dev_err(dev->dev, "%s: %s\n", __func__, abort_sources[i]); - - if (abort_source & DW_IC_TX_ARB_LOST) - return -EAGAIN; - else if (abort_source & DW_IC_TX_ABRT_GCALL_READ) - return -EINVAL; /* wrong msgs[] data */ - else - return -EIO; -} - -/* - * 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; - dev->abort_source = 0; - - ret = i2c_dw_wait_bus_not_busy(dev); - if (ret < 0) - goto done; - - /* start the transfers */ - i2c_dw_xfer_init(dev); - - /* 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)) { - /* Disable the adapter */ - writel(0, dev->base + DW_IC_ENABLE); - ret = num; - goto done; - } - - /* We have an error */ - if (dev->cmd_err == DW_IC_ERR_TX_ABRT) { - ret = i2c_dw_handle_tx_abort(dev); - goto done; - } - 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 | - I2C_FUNC_SMBUS_BYTE | - I2C_FUNC_SMBUS_BYTE_DATA | - I2C_FUNC_SMBUS_WORD_DATA | - I2C_FUNC_SMBUS_I2C_BLOCK; -} - -static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev) -{ - u32 stat; - - /* - * The IC_INTR_STAT register just indicates "enabled" interrupts. - * Ths unmasked raw version of interrupt status bits are available - * in the IC_RAW_INTR_STAT register. - * - * That is, - * stat = readl(IC_INTR_STAT); - * equals to, - * stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK); - * - * The raw version might be useful for debugging purposes. - */ - stat = readl(dev->base + DW_IC_INTR_STAT); - - /* - * Do not use the IC_CLR_INTR register to clear interrupts, or - * you'll miss some interrupts, triggered during the period from - * readl(IC_INTR_STAT) to readl(IC_CLR_INTR). - * - * Instead, use the separately-prepared IC_CLR_* registers. - */ - if (stat & DW_IC_INTR_RX_UNDER) - readl(dev->base + DW_IC_CLR_RX_UNDER); - if (stat & DW_IC_INTR_RX_OVER) - readl(dev->base + DW_IC_CLR_RX_OVER); - if (stat & DW_IC_INTR_TX_OVER) - readl(dev->base + DW_IC_CLR_TX_OVER); - if (stat & DW_IC_INTR_RD_REQ) - readl(dev->base + DW_IC_CLR_RD_REQ); - if (stat & DW_IC_INTR_TX_ABRT) { - /* - * The IC_TX_ABRT_SOURCE register is cleared whenever - * the IC_CLR_TX_ABRT is read. Preserve it beforehand. - */ - dev->abort_source = readl(dev->base + DW_IC_TX_ABRT_SOURCE); - readl(dev->base + DW_IC_CLR_TX_ABRT); - } - if (stat & DW_IC_INTR_RX_DONE) - readl(dev->base + DW_IC_CLR_RX_DONE); - if (stat & DW_IC_INTR_ACTIVITY) - readl(dev->base + DW_IC_CLR_ACTIVITY); - if (stat & DW_IC_INTR_STOP_DET) - readl(dev->base + DW_IC_CLR_STOP_DET); - if (stat & DW_IC_INTR_START_DET) - readl(dev->base + DW_IC_CLR_START_DET); - if (stat & DW_IC_INTR_GEN_CALL) - readl(dev->base + DW_IC_CLR_GEN_CALL); - - return stat; -} - -/* - * 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; - u32 stat; - - stat = i2c_dw_read_clear_intrbits(dev); - dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat); - - if (stat & DW_IC_INTR_TX_ABRT) { - dev->cmd_err |= DW_IC_ERR_TX_ABRT; - dev->status = STATUS_IDLE; - - /* - * Anytime TX_ABRT is set, the contents of the tx/rx - * buffers are flushed. Make sure to skip them. - */ - writel(0, dev->base + DW_IC_INTR_MASK); - goto tx_aborted; - } - - if (stat & DW_IC_INTR_RX_FULL) - i2c_dw_read(dev); - - if (stat & DW_IC_INTR_TX_EMPTY) - i2c_dw_xfer_msg(dev); - - /* - * No need to modify or disable the interrupt mask here. - * i2c_dw_xfer_msg() will take care of it according to - * the current transmit status. - */ - -tx_aborted: - if ((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err) - 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, *ioarea; - int irq, 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_irq(pdev, 0); - if (irq < 0) { - dev_err(&pdev->dev, "no irq resource?\n"); - return irq; /* -ENXIO */ - } - - 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); - mutex_init(&dev->lock); - dev->dev = get_device(&pdev->dev); - dev->irq = irq; - 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); - - writel(0, dev->base + DW_IC_INTR_MASK); /* disable IRQ */ - r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, 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; - - writel(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"); |