[PATCH] GTA0[12]: fix calypso sysfs power_on handling

[Paul Fertser]

This implements a proper scheme of controlling powering on of the Calypso
GSM modem which should be activated with a "push-button" connected to
MODEM_ON line.

Also a workaround for firmware bug of moko10 and earlier implemented to
force calypso to pull IRQ line down after powering on.

The "reset" sysfs node is left for compatibility with userspace (without it
gsm0710muxd breaks) but it does nothing (NC on hardware level on GTA02
anyway).

I tested flashing the GSM firmware (on GTA02) with this patch (using only
fluid and power_on node) and can confirm that it's working as reliably as
with accessing gpio directly per instructions.

The credit goes to Joerg Reisenweber for discussions and clarifications on
how this should be done properly.

Signed-off-by: Paul Fertser <fercerpav at gmail.com>
---
 arch/arm/plat-s3c24xx/neo1973_pm_gsm.c |   32 ++++++++++++++++++--------------
 1 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/arch/arm/plat-s3c24xx/neo1973_pm_gsm.c b/arch/arm/plat-s3c24xx/neo1973_pm_gsm.c
index 08cdf77..c493018 100644
--- a/arch/arm/plat-s3c24xx/neo1973_pm_gsm.c
+++ b/arch/arm/plat-s3c24xx/neo1973_pm_gsm.c
@@ -18,6 +18,7 @@
 #include <linux/console.h>
 #include <linux/errno.h>
 #include <linux/interrupt.h>
+#include <linux/delay.h>
 
 #include <mach/gpio.h>
 #include <asm/mach-types.h>
@@ -67,13 +68,12 @@ static ssize_t gsm_read(struct device *dev, struct device_attribute *attr,
 			char *buf)
 {
 	if (!strcmp(attr->attr.name, "power_on")) {
-		if (s3c2410_gpio_getpin(GTA01_GPIO_MODEM_ON))
-			goto out_1;
-	} else if (!strcmp(attr->attr.name, "reset")) {
-		if (machine_is_neo1973_gta01() && s3c2410_gpio_getpin(GTA01_GPIO_MODEM_RST))
-			goto out_1;
-		else if (machine_is_neo1973_gta02() && s3c2410_gpio_getpin(GTA02_GPIO_MODEM_RST))
-			goto out_1;
+		if (gta01_gsm.gpio_ngsm_en) {
+			if (!s3c2410_gpio_getpin(gta01_gsm.gpio_ngsm_en))
+				goto out_1;
+		} else if (machine_is_neo1973_gta02())
+			if (pcf50633_gpio_get(gta02_pcf, PCF50633_GPIO2))
+				goto out_1;
 	} else if (!strcmp(attr->attr.name, "download")) {
 		if (machine_is_neo1973_gta01()) {
 			if (s3c2410_gpio_getpin(GTA01_GPIO_MODEM_DNLOAD))
@@ -118,15 +118,24 @@ static ssize_t gsm_write(struct device *dev, struct device_attribute *attr,
 				case GTA02v5_SYSTEM_REV:
 				case GTA02v6_SYSTEM_REV:
 					pcf50633_gpio_set(gta02_pcf,
-							  PCF50633_GPIO2, 1);
+							  PCF50633_GPIO2, 7);
 					break;
 				}
 			}
+			msleep(100);
 
 			neo1973_gpb_setpin(GTA01_GPIO_MODEM_ON, 1);
-		} else {
+			msleep(500);
 			neo1973_gpb_setpin(GTA01_GPIO_MODEM_ON, 0);
 
+			/* workaround for calypso firmware moko10 and earlier,
+			   without this it will leave IRQ line high after booting */
+			s3c2410_gpio_setpin(S3C2410_GPH1, 1);
+			s3c2410_gpio_cfgpin(S3C2410_GPH1, S3C2410_GPH1_OUTP);
+			msleep(1000);
+			s3c2410_gpio_cfgpin(S3C2410_GPH1, S3C2410_GPH1_nRTS0);
+		} else {
+			/* FIXME should all GPIOs connected to the modem be tri-stated? */
 			if (machine_is_neo1973_gta02()) {
 				switch (system_rev) {
 				case GTA02v2_SYSTEM_REV:
@@ -151,11 +160,6 @@ static ssize_t gsm_write(struct device *dev, struct device_attribute *attr,
 					 "serial console\n");
 			}
 		}
-	} else if (!strcmp(attr->attr.name, "reset")) {
-		if (machine_is_neo1973_gta01())
-			neo1973_gpb_setpin(GTA01_GPIO_MODEM_RST, on);
-		else if (machine_is_neo1973_gta02())
-			neo1973_gpb_setpin(GTA02_GPIO_MODEM_RST, on);
 	} else if (!strcmp(attr->attr.name, "download")) {
 		if (machine_is_neo1973_gta01())
 			s3c2410_gpio_setpin(GTA01_GPIO_MODEM_DNLOAD, on);
-- 
1.5.2.2