* [PATCH] [OMAP] [I2C-2430] FIFO Handling support and broken hw workaround
@ 2007-05-12 0:48 nishanth menon
2007-05-16 22:04 ` Tony Lindgren
0 siblings, 1 reply; 2+ messages in thread
From: nishanth menon @ 2007-05-12 0:48 UTC (permalink / raw)
To: Linux OMAP
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Hi All,
*) xfers based can use FIFO on FIFO capable devices
*) Prevents errors for HSI2C if FIFO is not used
*) Should co-exist with no-FIFO support h/w also
*) Implemented errenous handling of STT-STP handling on SDP2430
Signed-off-by: Nishanth Menon <menon.nishanth@gmail.com>
Regards,
Nishanth Menon
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From 7e1c5803cd329d9ca7a3eaae114c36a402d9daba Mon Sep 17 00:00:00 2001
From: Nishanth Menon <menon.nishanth@gmail.com>
Date: Fri, 11 May 2007 19:36:02 -0500
Subject: [PATCH] [OMAP] [I2C-2430] FIFO Handling support and broken hw workaround
*) xfers based can use FIFO on FIFO capable devices
*) Prevents errors for HSI2C if FIFO is not used
*) Should co-exist with no-FIFO support h/w also
*) Implemented errenous handling of STT-STP handling on SDP2430
Signed-off-by: Nishanth Menon <menon.nishanth@gmail.com>
---
drivers/i2c/busses/i2c-omap.c | 153 +++++++++++++++++++++++++++++++----------
1 files changed, 115 insertions(+), 38 deletions(-)
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index fcc6592..1441ac8 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -61,8 +61,11 @@
#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 draining int enable */
+#define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer draining 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 */
@@ -70,7 +73,8 @@
#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 */
@@ -84,12 +88,14 @@
/* 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) */
@@ -133,7 +139,12 @@ 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 */
};
static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
@@ -296,6 +307,14 @@ 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);
@@ -303,7 +322,8 @@ 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;
}
@@ -375,6 +395,11 @@ 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;
@@ -382,16 +407,27 @@ 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);
+ if (dev->b_hw && stop) {
+ /* H/w behavior: dont write stt and stp together.. */
+ while (omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) & OMAP_I2C_CON_STT) {
+ /* Dont do anything - this will come in a couple of loops at max*/
+ }
+ 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;
@@ -555,45 +591,73 @@ omap_i2c_isr(int this_irq, void *dev_id)
omap_i2c_complete_cmd(dev, 0);
continue;
}
- 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--;
- /*
- * Data reg in 2430 is 8 bit wide,
- */
- if (!cpu_is_omap2430()) {
- if (dev->buf_len) {
- *dev->buf++ = w >> 8;
- dev->buf_len--;
+ if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
+ u8 num_bytes = 1;
+ if (dev->fifo_size) {
+ num_bytes = (stat & OMAP_I2C_STAT_RRDY) ? dev->fifo_size :
+ 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;
+ dev->buf_len--;
+ /*
+ * Data reg in 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--;
- /*
- * Data reg in 2430 is 8 bit wide,
- */
- if (!cpu_is_omap2430()) {
- if (dev->buf_len) {
- w |= *dev->buf++ << 8;
- dev->buf_len--;
+ if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
+ u8 num_bytes = 1;
+ if (dev->fifo_size) {
+ num_bytes = (stat & OMAP_I2C_STAT_XRDY) ? dev->fifo_size :
+ omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG);
+ }
+ while (num_bytes) {
+ num_bytes--;
+ w = 0;
+ if (dev->buf_len) {
+ w = *dev->buf++;
+ dev->buf_len--;
+ /*
+ * Data reg in 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) {
@@ -676,6 +740,19 @@ 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()) {
+ /* Set up the fifo size - Get total size */
+ dev->fifo_size = 0x8 <<
+ ((omap_i2c_read_reg(dev, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3);
+ /*
+ * 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);
--
1.5.0.6
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] [OMAP] [I2C-2430] FIFO Handling support and broken hw workaround
2007-05-12 0:48 [PATCH] [OMAP] [I2C-2430] FIFO Handling support and broken hw workaround nishanth menon
@ 2007-05-16 22:04 ` Tony Lindgren
0 siblings, 0 replies; 2+ messages in thread
From: Tony Lindgren @ 2007-05-16 22:04 UTC (permalink / raw)
To: nishanth menon; +Cc: Linux OMAP
* nishanth menon <menon.nishanth@gmail.com> [070511 17:53]:
> Hi All,
>
> *) xfers based can use FIFO on FIFO capable devices
> *) Prevents errors for HSI2C if FIFO is not used
> *) Should co-exist with no-FIFO support h/w also
> *) Implemented errenous handling of STT-STP handling on SDP2430
Great, pushing today.
Tony
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