[PATCH v4 2/3] i2c: Add driver for Cadence I2C controller
Wolfram Sang
wsa at the-dreams.de
Fri Apr 4 07:38:47 PDT 2014
On Thu, Apr 03, 2014 at 10:59:26AM -0700, Soren Brinkmann wrote:
> Add a driver for the Cadence I2C controller. This controller is for
> example found in Xilinx Zynq.
>
> Signed-off-by: Soren Brinkmann <soren.brinkmann at xilinx.com>
> Tested-by: Michal Simek <michal.simek at xilinx.com>
> Reviewed-by: Harini Katakam <harinik at xilinx.com>
Only minor stuff, but since you resend anyhow because of 400kHz issue...
> +static void cdns_i2c_mrecv(struct cdns_i2c *id)
> +{
> + unsigned int ctrl_reg;
> + unsigned int isr_status;
> +
> + id->p_recv_buf = id->p_msg->buf;
> + id->recv_count = id->p_msg->len;
> +
> + /* Put the controller in master receive mode and clear the FIFO */
> + ctrl_reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
> + ctrl_reg |= CDNS_I2C_CR_RW | CDNS_I2C_CR_CLR_FIFO;
> +
> + if ((id->p_msg->flags & I2C_M_RECV_LEN) == I2C_M_RECV_LEN)
'if (id->p_msg->flags & I2C_M_RECV_LEN)' is enough.
> + /* Report the other error interrupts to application as EIO */
> + if (id->err_status & (CDNS_I2C_IXR_RX_UNF |
> + CDNS_I2C_IXR_TX_OVF |
> + CDNS_I2C_IXR_RX_OVF |
> + CDNS_I2C_IXR_NACK)) {
> + cdns_i2c_master_reset(adap);
> + return -EIO;
> + }
NACK is returned as -ENXIO. Check 'Documentation/i2c/fault-codes' for
standard patterns. I'd think the rest is EIO, though.
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