This patch does i2c init/re-init for every transfer.
Avoids a i2c controller reset every time
Signed-off-by: Jouni Hogander <jouni.hogander@xxxxxxxxx>
Signed-off-by: Rajendra Nayak <rnayak@xxxxxx>
---
drivers/i2c/busses/i2c-omap.c | 41 +++++++++++++++++++++++++++--------------
1 files changed, 27 insertions(+), 14 deletions(-)
Index: linux-omap-2.6/drivers/i2c/busses/i2c-omap.c
===================================================================
--- linux-omap-2.6.orig/drivers/i2c/busses/i2c-omap.c 2008-09-25 16:26:40.000000000 +0530
+++ linux-omap-2.6/drivers/i2c/busses/i2c-omap.c 2008-09-25 16:27:14.000000000 +0530
@@ -147,6 +147,10 @@ struct omap_i2c_dev {
unsigned b_hw:1; /* bad h/w fixes */
unsigned idle:1;
u16 iestate; /* Saved interrupt register */
+ u16 pscstate;
+ u16 scllstate;
+ u16 sclhstate;
+ u16 bufstate;
};
static inline void omap_i2c_write_reg(struct omap_i2c_dev *i2c_dev,
@@ -209,16 +213,20 @@ static void omap_i2c_unidle(struct omap_
if (dev->iclk != NULL)
clk_enable(dev->iclk);
clk_enable(dev->fclk);
+ if (cpu_is_omap34xx()) {
+ omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
+ omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
+ omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
+ omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, dev->bufstate);
+ }
dev->idle = 0;
- if (dev->iestate)
- omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
+ omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
}
static void omap_i2c_idle(struct omap_i2c_dev *dev)
{
u16 iv;
- dev->iestate = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, 0);
if (dev->rev1)
iv = omap_i2c_read_reg(dev, OMAP_I2C_IV_REG);
@@ -238,7 +246,7 @@ static void omap_i2c_idle(struct omap_i2
static int omap_i2c_init(struct omap_i2c_dev *dev)
{
- u16 psc = 0, scll = 0, sclh = 0;
+ u16 psc = 0, scll = 0, sclh = 0, buf = 0;
u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
unsigned long fclk_rate = 12000000;
unsigned long timeout;
@@ -327,23 +335,28 @@ static int omap_i2c_init(struct omap_i2c
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);
+ if (dev->fifo_size) {
+ /* Note: setup required fifo size - 1. RTRSH and XTRSH */
+ buf = (dev->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR |
+ (dev->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR;
+ omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
+ }
/* Take the I2C module out of reset: */
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
/* Enable interrupts */
- omap_i2c_write_reg(dev, OMAP_I2C_IE_REG,
- (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
+ dev->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
OMAP_I2C_IE_AL) | ((dev->fifo_size) ?
- (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0));
+ (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
+ omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
+ if (cpu_is_omap34xx()) {
+ dev->pscstate = psc;
+ dev->scllstate = scll;
+ dev->sclhstate = sclh;
+ dev->bufstate = buf;
+ }
return 0;
}
--
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