summaryrefslogtreecommitdiffstats
path: root/drivers/i2c/busses/i2c-au1550.c
diff options
context:
space:
mode:
authorManuel Lauss <mano@roarinelk.homelinux.net>2008-07-14 22:38:34 +0200
committerJean Delvare <khali@mahadeva.delvare>2008-07-14 22:38:34 +0200
commitf09f71b24e77a2f2b4e5c98311c8804fc61ad8bc (patch)
tree6213e3f5ddf6d929dc294bec952903b3691ae505 /drivers/i2c/busses/i2c-au1550.c
parentf6a7110520037ba786f17b53790c6eb8a3d4ef55 (diff)
i2c-au1550: Fix PM support
Fix driver power management: - suspend the PSC while driver is idle. - move PSC init/deinit to separate functions, as PSC must be initialized/shutdown on resume/suspend. Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-au1550.c')
-rw-r--r--drivers/i2c/busses/i2c-au1550.c130
1 files changed, 75 insertions, 55 deletions
diff --git a/drivers/i2c/busses/i2c-au1550.c b/drivers/i2c/busses/i2c-au1550.c
index cae9dc89d88..66a04c2c660 100644
--- a/drivers/i2c/busses/i2c-au1550.c
+++ b/drivers/i2c/busses/i2c-au1550.c
@@ -269,9 +269,13 @@ static int
au1550_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
{
struct i2c_au1550_data *adap = i2c_adap->algo_data;
+ volatile psc_smb_t *sp = (volatile psc_smb_t *)adap->psc_base;
struct i2c_msg *p;
int i, err = 0;
+ sp->psc_ctrl = PSC_CTRL_ENABLE;
+ au_sync();
+
for (i = 0; !err && i < num; i++) {
p = &msgs[i];
err = do_address(adap, p->addr, p->flags & I2C_M_RD,
@@ -288,6 +292,10 @@ au1550_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
*/
if (err == 0)
err = num;
+
+ sp->psc_ctrl = PSC_CTRL_SUSPEND;
+ au_sync();
+
return err;
}
@@ -302,6 +310,61 @@ static const struct i2c_algorithm au1550_algo = {
.functionality = au1550_func,
};
+static void i2c_au1550_setup(struct i2c_au1550_data *priv)
+{
+ volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base;
+ u32 stat;
+
+ sp->psc_ctrl = PSC_CTRL_DISABLE;
+ au_sync();
+ sp->psc_sel = PSC_SEL_PS_SMBUSMODE;
+ sp->psc_smbcfg = 0;
+ au_sync();
+ sp->psc_ctrl = PSC_CTRL_ENABLE;
+ au_sync();
+ do {
+ stat = sp->psc_smbstat;
+ au_sync();
+ } while ((stat & PSC_SMBSTAT_SR) == 0);
+
+ sp->psc_smbcfg = (PSC_SMBCFG_RT_FIFO8 | PSC_SMBCFG_TT_FIFO8 |
+ PSC_SMBCFG_DD_DISABLE);
+
+ /* Divide by 8 to get a 6.25 MHz clock. The later protocol
+ * timings are based on this clock.
+ */
+ sp->psc_smbcfg |= PSC_SMBCFG_SET_DIV(PSC_SMBCFG_DIV8);
+ sp->psc_smbmsk = PSC_SMBMSK_ALLMASK;
+ au_sync();
+
+ /* Set the protocol timer values. See Table 71 in the
+ * Au1550 Data Book for standard timing values.
+ */
+ sp->psc_smbtmr = PSC_SMBTMR_SET_TH(0) | PSC_SMBTMR_SET_PS(15) | \
+ PSC_SMBTMR_SET_PU(15) | PSC_SMBTMR_SET_SH(15) | \
+ PSC_SMBTMR_SET_SU(15) | PSC_SMBTMR_SET_CL(15) | \
+ PSC_SMBTMR_SET_CH(15);
+ au_sync();
+
+ sp->psc_smbcfg |= PSC_SMBCFG_DE_ENABLE;
+ do {
+ stat = sp->psc_smbstat;
+ au_sync();
+ } while ((stat & PSC_SMBSTAT_SR) == 0);
+
+ sp->psc_ctrl = PSC_CTRL_SUSPEND;
+ au_sync();
+}
+
+static void i2c_au1550_disable(struct i2c_au1550_data *priv)
+{
+ volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base;
+
+ sp->psc_smbcfg = 0;
+ sp->psc_ctrl = PSC_CTRL_DISABLE;
+ au_sync();
+}
+
/*
* registering functions to load algorithms at runtime
* Prior to calling us, the 50MHz clock frequency and routing
@@ -311,9 +374,7 @@ static int __devinit
i2c_au1550_probe(struct platform_device *pdev)
{
struct i2c_au1550_data *priv;
- volatile psc_smb_t *sp;
struct resource *r;
- u32 stat;
int ret;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -348,43 +409,7 @@ i2c_au1550_probe(struct platform_device *pdev)
/* Now, set up the PSC for SMBus PIO mode.
*/
- sp = (volatile psc_smb_t *)priv->psc_base;
- sp->psc_ctrl = PSC_CTRL_DISABLE;
- au_sync();
- sp->psc_sel = PSC_SEL_PS_SMBUSMODE;
- sp->psc_smbcfg = 0;
- au_sync();
- sp->psc_ctrl = PSC_CTRL_ENABLE;
- au_sync();
- do {
- stat = sp->psc_smbstat;
- au_sync();
- } while ((stat & PSC_SMBSTAT_SR) == 0);
-
- sp->psc_smbcfg = (PSC_SMBCFG_RT_FIFO8 | PSC_SMBCFG_TT_FIFO8 |
- PSC_SMBCFG_DD_DISABLE);
-
- /* Divide by 8 to get a 6.25 MHz clock. The later protocol
- * timings are based on this clock.
- */
- sp->psc_smbcfg |= PSC_SMBCFG_SET_DIV(PSC_SMBCFG_DIV8);
- sp->psc_smbmsk = PSC_SMBMSK_ALLMASK;
- au_sync();
-
- /* Set the protocol timer values. See Table 71 in the
- * Au1550 Data Book for standard timing values.
- */
- sp->psc_smbtmr = PSC_SMBTMR_SET_TH(0) | PSC_SMBTMR_SET_PS(15) | \
- PSC_SMBTMR_SET_PU(15) | PSC_SMBTMR_SET_SH(15) | \
- PSC_SMBTMR_SET_SU(15) | PSC_SMBTMR_SET_CL(15) | \
- PSC_SMBTMR_SET_CH(15);
- au_sync();
-
- sp->psc_smbcfg |= PSC_SMBCFG_DE_ENABLE;
- do {
- stat = sp->psc_smbstat;
- au_sync();
- } while ((stat & PSC_SMBSTAT_DR) == 0);
+ i2c_au1550_setup(priv);
ret = i2c_add_numbered_adapter(&priv->adap);
if (ret == 0) {
@@ -392,10 +417,7 @@ i2c_au1550_probe(struct platform_device *pdev)
return 0;
}
- /* disable the PSC */
- sp->psc_smbcfg = 0;
- sp->psc_ctrl = PSC_CTRL_DISABLE;
- au_sync();
+ i2c_au1550_disable(priv);
release_resource(priv->ioarea);
kfree(priv->ioarea);
@@ -409,27 +431,24 @@ static int __devexit
i2c_au1550_remove(struct platform_device *pdev)
{
struct i2c_au1550_data *priv = platform_get_drvdata(pdev);
- volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base;
platform_set_drvdata(pdev, NULL);
i2c_del_adapter(&priv->adap);
- sp->psc_smbcfg = 0;
- sp->psc_ctrl = PSC_CTRL_DISABLE;
- au_sync();
+ i2c_au1550_disable(priv);
release_resource(priv->ioarea);
kfree(priv->ioarea);
kfree(priv);
return 0;
}
+#ifdef CONFIG_PM
static int
i2c_au1550_suspend(struct platform_device *pdev, pm_message_t state)
{
struct i2c_au1550_data *priv = platform_get_drvdata(pdev);
- volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base;
- sp->psc_ctrl = PSC_CTRL_SUSPEND;
- au_sync();
+ i2c_au1550_disable(priv);
+
return 0;
}
@@ -437,14 +456,15 @@ static int
i2c_au1550_resume(struct platform_device *pdev)
{
struct i2c_au1550_data *priv = platform_get_drvdata(pdev);
- volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base;
- sp->psc_ctrl = PSC_CTRL_ENABLE;
- au_sync();
- while (!(sp->psc_smbstat & PSC_SMBSTAT_SR))
- au_sync();
+ i2c_au1550_setup(priv);
+
return 0;
}
+#else
+#define i2c_au1550_suspend NULL
+#define i2c_au1550_resume NULL
+#endif
static struct platform_driver au1xpsc_smbus_driver = {
.driver = {