On Thu, Sep 25, 2008 at 10:53:50AM +0300, Tony Lindgren wrote:
> From: Nishanth Menon <menon.nishanth@xxxxxxxxx>
>
> Based on an earlier patch from Nishant Menon:
>
> - Transfers can use FIFO on FIFO capable devices
> - Prevents errors for HSI2C if FIFO is not used
> - Implemented errenous handling of STT-STP handling on SDP2430
>
> Also merged in is a fix from Jaron Marini to fix occasional i2c
> hang if OMAP_I2C_CON_STT remains asserted.
This looks ok
> Signed-off-by: Jason P Marini <jason.marini@xxxxxxxxx>
> Signed-off-by: Nishanth Menon <menon.nishanth@xxxxxxxxx>
> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-omap.c | 189 ++++++++++++++++++++++++++++++++---------
> 1 files changed, 149 insertions(+), 40 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
> index 0d30790..ded4636 100644
> --- a/drivers/i2c/busses/i2c-omap.c
> +++ b/drivers/i2c/busses/i2c-omap.c
> @@ -55,8 +55,11 @@
> #define OMAP_I2C_SCLL_REG 0x34
> #define OMAP_I2C_SCLH_REG 0x38
> #define OMAP_I2C_SYSTEST_REG 0x3c
> +#define OMAP_I2C_BUFSTAT_REG 0x40
>
> /* I2C Interrupt Enable Register (OMAP_I2C_IE): */
> +#define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */
> +#define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer drain int enable */
> #define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */
> #define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */
> #define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */
> @@ -64,7 +67,8 @@
> #define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */
>
> /* I2C Status Register (OMAP_I2C_STAT): */
> -#define OMAP_I2C_STAT_SBD (1 << 15) /* Single byte data */
> +#define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */
> +#define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */
> #define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */
> #define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */
> #define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */
> @@ -78,12 +82,14 @@
>
> /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
> #define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */
> +#define OMAP_I2C_BUF_RXFIF_CLR (1 << 14) /* RX FIFO Clear */
> #define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */
> +#define OMAP_I2C_BUF_TXFIF_CLR (1 << 6) /* TX FIFO Clear */
>
> /* I2C Configuration Register (OMAP_I2C_CON): */
> #define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */
> #define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */
> -#define OMAP_I2C_CON_OPMODE (1 << 12) /* High Speed support */
> +#define OMAP_I2C_CON_OPMODE_HS (1 << 12) /* High Speed support */
> #define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */
> #define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */
> #define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */
> @@ -127,7 +133,12 @@ struct omap_i2c_dev {
> u8 *buf;
> size_t buf_len;
> struct i2c_adapter adapter;
> + u8 fifo_size; /* use as flag and value
> + * fifo_size==0 implies no fifo
> + * if set, should be trsh+1
> + */
> unsigned rev1:1;
> + unsigned b_hw:1; /* bad h/w fixes */
> unsigned idle:1;
> u16 iestate; /* Saved interrupt register */
> };
> @@ -310,6 +321,14 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
> omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, scll);
> omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, sclh);
>
> + if (dev->fifo_size)
> + /* Note: setup required fifo size - 1 */
> + omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG,
> + (dev->fifo_size - 1) << 8 | /* RTRSH */
> + OMAP_I2C_BUF_RXFIF_CLR |
> + (dev->fifo_size - 1) | /* XTRSH */
> + OMAP_I2C_BUF_TXFIF_CLR);
> +
> /* Take the I2C module out of reset: */
> omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
>
> @@ -317,7 +336,8 @@ static int omap_i2c_init(struct omap_i2c_dev *dev)
> omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
> (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
> OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
> - OMAP_I2C_IE_AL));
> + OMAP_I2C_IE_AL) | ((dev->fifo_size) ?
> + (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0));
> return 0;
> }
>
> @@ -364,6 +384,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
>
> omap_i2c_write_reg(dev, OMAP_I2C_CNT_REG, dev->buf_len);
>
> + /* Clear the FIFO Buffers */
> + w = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
> + w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
> + omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, w);
> +
> init_completion(&dev->cmd_complete);
> dev->cmd_err = 0;
>
> @@ -371,16 +396,38 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
>
> /* High speed configuration */
> if (dev->speed > 400)
> - w |= OMAP_I2C_CON_OPMODE;
> + w |= OMAP_I2C_CON_OPMODE_HS;
>
> if (msg->flags & I2C_M_TEN)
> w |= OMAP_I2C_CON_XA;
> if (!(msg->flags & I2C_M_RD))
> w |= OMAP_I2C_CON_TRX;
> - if (stop)
> + if (!dev->b_hw && stop)
> w |= OMAP_I2C_CON_STP;
> omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
>
> + /*
> + * Don't write stt and stp together on some hardware
> + */
> + if (dev->b_hw && stop) {
> + unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
> + u16 con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
> + while (con & OMAP_I2C_CON_STT) {
> + con = omap_i2c_read_reg(dev, OMAP_I2C_CON_REG);
> +
> + /* Let the user know if i2c is in a bad state */
> + if (time_after(jiffies, delay)) {
> + dev_err(dev->dev, "controller timed out "
> + "waiting for start condition to finish\n");
> + return -ETIMEDOUT;
> + }
> + cpu_relax();
> + }
> +
> + w |= OMAP_I2C_CON_STP;
> + w &= ~OMAP_I2C_CON_STT;
> + omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
> + }
> r = wait_for_completion_timeout(&dev->cmd_complete,
> OMAP_I2C_TIMEOUT);
> dev->buf_len = 0;
> @@ -525,7 +572,7 @@ omap_i2c_isr(int this_irq, void *dev_id)
> struct omap_i2c_dev *dev = dev_id;
> u16 bits;
> u16 stat, w;
> - int count = 0;
> + int err, count = 0;
>
> if (dev->idle)
> return IRQ_NONE;
> @@ -540,39 +587,94 @@ omap_i2c_isr(int this_irq, void *dev_id)
>
> omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
>
> - if (stat & OMAP_I2C_STAT_ARDY) {
> - omap_i2c_complete_cmd(dev, 0);
> - continue;
> + err = 0;
> + if (stat & OMAP_I2C_STAT_NACK) {
> + err |= OMAP_I2C_STAT_NACK;
> + omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
> + OMAP_I2C_CON_STP);
> }
> - if (stat & OMAP_I2C_STAT_RRDY) {
> - w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
> - if (dev->buf_len) {
> - *dev->buf++ = w;
> - dev->buf_len--;
> + if (stat & OMAP_I2C_STAT_AL) {
> + dev_err(dev->dev, "Arbitration lost\n");
> + err |= OMAP_I2C_STAT_AL;
> + }
> + if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
> + OMAP_I2C_STAT_AL))
> + omap_i2c_complete_cmd(dev, err);
> + if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
> + u8 num_bytes = 1;
> + if (dev->fifo_size) {
> + if (stat & OMAP_I2C_STAT_RRDY)
> + num_bytes = dev->fifo_size;
> + else
> + num_bytes = omap_i2c_read_reg(dev,
> + OMAP_I2C_BUFSTAT_REG);
> + }
> + while (num_bytes) {
> + num_bytes--;
> + w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
> if (dev->buf_len) {
> - *dev->buf++ = w >> 8;
> + *dev->buf++ = w;
> dev->buf_len--;
> + /* Data reg from 2430 is 8 bit wide */
> + if (!cpu_is_omap2430()) {
> + if (dev->buf_len) {
> + *dev->buf++ = w >> 8;
> + dev->buf_len--;
> + }
> + }
> + } else {
> + if (stat & OMAP_I2C_STAT_RRDY)
> + dev_err(dev->dev,
> + "RRDY IRQ while no data"
> + " requested\n");
> + if (stat & OMAP_I2C_STAT_RDR)
> + dev_err(dev->dev,
> + "RDR IRQ while no data"
> + " requested\n");
> + break;
> }
> - } else
> - dev_err(dev->dev, "RRDY IRQ while no data "
> - "requested\n");
> - omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
> + }
> + omap_i2c_ack_stat(dev,
> + stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
> continue;
> }
> - if (stat & OMAP_I2C_STAT_XRDY) {
> - w = 0;
> - if (dev->buf_len) {
> - w = *dev->buf++;
> - dev->buf_len--;
> + if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
> + u8 num_bytes = 1;
> + if (dev->fifo_size) {
> + if (stat & OMAP_I2C_STAT_XRDY)
> + num_bytes = dev->fifo_size;
> + else
> + num_bytes = omap_i2c_read_reg(dev,
> + OMAP_I2C_BUFSTAT_REG);
> + }
> + while (num_bytes) {
> + num_bytes--;
> + w = 0;
> if (dev->buf_len) {
> - w |= *dev->buf++ << 8;
> + w = *dev->buf++;
> dev->buf_len--;
> + /* Data reg from 2430 is 8 bit wide */
> + if (!cpu_is_omap2430()) {
> + if (dev->buf_len) {
> + w |= *dev->buf++ << 8;
> + dev->buf_len--;
> + }
> + }
> + } else {
> + if (stat & OMAP_I2C_STAT_XRDY)
> + dev_err(dev->dev,
> + "XRDY IRQ while no "
> + "data to send\n");
> + if (stat & OMAP_I2C_STAT_XDR)
> + dev_err(dev->dev,
> + "XDR IRQ while no "
> + "data to send\n");
> + break;
> }
> - } else
> - dev_err(dev->dev, "XRDY IRQ while no "
> - "data to send\n");
> - omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
> - omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
> + omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
> + }
> + omap_i2c_ack_stat(dev,
> + stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
> continue;
> }
> if (stat & OMAP_I2C_STAT_ROVR) {
> @@ -580,18 +682,9 @@ omap_i2c_isr(int this_irq, void *dev_id)
> dev->cmd_err |= OMAP_I2C_STAT_ROVR;
> }
> if (stat & OMAP_I2C_STAT_XUDF) {
> - dev_err(dev->dev, "Transmit overflow\n");
> + dev_err(dev->dev, "Transmit underflow\n");
> dev->cmd_err |= OMAP_I2C_STAT_XUDF;
> }
> - if (stat & OMAP_I2C_STAT_NACK) {
> - omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
> - omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
> - OMAP_I2C_CON_STP);
> - }
> - if (stat & OMAP_I2C_STAT_AL) {
> - dev_err(dev->dev, "Arbitration lost\n");
> - omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
> - }
> }
>
> return count ? IRQ_HANDLED : IRQ_NONE;
> @@ -655,6 +748,22 @@ omap_i2c_probe(struct platform_device *pdev)
> if (cpu_is_omap15xx())
> dev->rev1 = omap_i2c_read_reg(dev, OMAP_I2C_REV_REG) < 0x20;
>
> + if (cpu_is_omap2430()) {
> + u16 s;
> +
> + /* Set up the fifo size - Get total size */
> + s = (omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
how about some constants for these instead of us having to guess what
is going on here?
> + dev->fifo_size = 0x8 << s;
> +
> + /*
> + * Set up notification threshold as half the total available
> + * size. This is to ensure that we can handle the status on int
> + * call back latencies.
> + */
> + dev->fifo_size = (dev->fifo_size / 2);
> + dev->b_hw = 1; /* Enable hardware fixes */
> + }
> +
> /* reset ASAP, clearing any IRQs */
> omap_i2c_init(dev);
>
> --
> 1.5.6.rc3.21.g8c6b5
>
>
> _______________________________________________
> i2c mailing list
> i2c@xxxxxxxxxxxxxx
> http://lists.lm-sensors.org/mailman/listinfo/i2c
--
Ben (ben@xxxxxxxxx, http://www.fluff.org/)
'a smiley only costs 4 bytes'
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