--- a/drivers/i2c/busses/i2c-cns3xxx.c +++ b/drivers/i2c/busses/i2c-cns3xxx.c @@ -2,8 +2,9 @@ * Cavium CNS3xxx I2C Host Controller * * Copyright 2010 Cavium Network - * Copyright 2011 Gateworks Corporation + * Copyright 2012 Gateworks Corporation * Chris Lang + * Tim Harvey * * This file is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License, Version 2, as @@ -63,13 +64,15 @@ #define STATE_ERROR 2 struct cns3xxx_i2c { - void __iomem *base; - wait_queue_head_t wait; - struct i2c_adapter adap; - struct i2c_msg *msg; - int state; /* see STATE_ */ - int rd_wr_len; - u8 *buf; + struct device *dev; + void __iomem *base; /* virtual */ + wait_queue_head_t wait; + struct i2c_adapter adap; + struct i2c_msg *msg; + u8 state; /* see STATE_ */ + u8 error; /* see TWI_STATUS register */ + int rd_wr_len; + u8 *buf; }; static u32 cns3xxx_i2c_func(struct i2c_adapter *adap) @@ -150,14 +153,18 @@ cns3xxx_i2c_xfer_msg(struct i2c_adapter // Start the Transfer i2c->state = 0; // Clear out the State + i2c->error = 0; I2C_CONTROLLER_REG |= (1 << 6); if (wait_event_timeout(i2c->wait, (i2c->state == STATE_ERROR) || (i2c->state == STATE_DONE), TWI_TIMEOUT)) { if (i2c->state == STATE_ERROR) { - return -EIO; + dev_dbg(i2c->dev, "controller error: 0x%2x", i2c->error); + return -EAGAIN; // try again } } else { + dev_err(i2c->dev, "controller timed out " + "waiting for start condition to finish\n"); return -ETIMEDOUT; } } @@ -238,6 +245,7 @@ static irqreturn_t cns3xxx_i2c_isr(int i if (stat & I2C_BUS_ERROR_FLAG) { i2c->state = STATE_ERROR; + i2c->error = (I2C_INTERRUPT_STATUS_REG & 0xff00)>>8; } else { if (i2c->msg->flags & I2C_M_RD) { for (i = 0; i <= i2c->rd_wr_len; i++) @@ -280,6 +288,7 @@ static int __devinit cns3xxx_i2c_probe(s goto request_mem_failed; } + i2c->dev = &pdev->dev; i2c->base = ioremap(res->start, res->end - res->start + 1); if (!i2c->base) { dev_err(&pdev->dev, "Unable to map registers\n");