[PATCH PM-0] OMAP3: I2C: Implement i2c save/restore

Jouni Hogander
2008-09-17T09:44:13Z

Save and restore needed registers instead of re-init.

Signed-off-by: Jouni Hogander <jouni.hogander@nokia.com>
---
drivers/i2c/busses/i2c-omap.c | 47 +++++++++++++++++++++++++++--------------
1 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index a661ed3..211d7b5 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -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 +213,22 @@ static void omap_i2c_unidle(struct omap_i2c_dev *dev)
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 +248,7 @@ static void omap_i2c_idle(struct omap_i2c_dev *dev)

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 +337,30 @@ 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);
+ 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;
}

@@ -503,8 +520,6 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)

omap_i2c_unidle(dev);

- omap_i2c_init(dev);
-
if ((r = omap_i2c_wait_for_bb(dev)) < 0)
goto out;

--
1.5.5