* Tony Lindgren <[EMAIL PROTECTED]> [080925 10:54]:
> From: Nishanth Menon <[EMAIL PROTECTED]>
>
> 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.
>
> Signed-off-by: Jason P Marini <[EMAIL PROTECTED]>
> Signed-off-by: Nishanth Menon <[EMAIL PROTECTED]>
> Signed-off-by: Tony Lindgren <[EMAIL PROTECTED]>
Here's this one update with current email address for Nishant
Menon as requested by Nishant.
Tony
>From 5ee572214da6efd0dfbd3765616caa0f03aca25d Mon Sep 17 00:00:00 2001
From: Nishanth Menon <[EMAIL PROTECTED]>
Date: Thu, 25 Sep 2008 10:46:43 +0300
Subject: [PATCH] i2c-omap: FIFO handling support and broken hw workaround for i2c-omap
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.
Signed-off-by: Jason P Marini <[EMAIL PROTECTED]>
Signed-off-by: Nishanth Menon <[EMAIL PROTECTED]>
Signed-off-by: Tony Lindgren <[EMAIL PROTECTED]>
---
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;
+ 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
