arm: tegra: enterprise: disable dsi_csi_rail in LP0

AVDD_DSI_CSI is shared by modem and dsi. If DSI turns
off this rail then HSIC fails after wakeup from modem.
This patch provides a way to turn on this rail from
modem as well as from DSI. Create two virtual power rails
from avdd_csi_dsi to control it from both the drivers separately.
This is enterprise specific change as per the power rail layout.

Bug 920881

(cherry picked from commit ab52b51c59f776ae770d48a28a2744e2db2e5d2f)
Reviewed-on: http://git-master/r/85656

Change-Id: I2e9c04a8f4e8d6fd20584b4e75657c1cb6d5c8bd
Signed-off-by: Vinayak Pane <vpane@nvidia.com>
Reviewed-on: http://git-master/r/89134
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Puneet Saxena <puneets@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>

1 files changed, 74 insertions, 0 deletions

diff --git a/arch/arm/mach-tegra/baseband-xmm-power.c b/arch/arm/mach-tegra/baseband-xmm-power.c
index 0e642d8ebcb3..2d41abc8571a 100644
--- a/arch/arm/mach-tegra/baseband-xmm-power.c
+++ b/arch/arm/mach-tegra/baseband-xmm-power.c
@@ -33,6 +33,7 @@
 #include <linux/suspend.h>
 #include <mach/usb_phy.h>
 #include "board.h"
+#include "board-enterprise.h"
 #include "devices.h"
 #include "gpio-names.h"
 #include "baseband-xmm-power.h"
@@ -107,11 +108,70 @@ static bool modem_sleep_flag;
 static spinlock_t xmm_lock;
 static DEFINE_MUTEX(xmm_onoff_mutex);
 static bool system_suspending;
+static struct regulator *enterprise_hsic_reg;
+static bool _hsic_reg_status;
 
 static void baseband_xmm_power_L2_resume(void);
 static int baseband_xmm_power_driver_handle_resume(
 			struct baseband_power_platform_data *data);
 
+static int tegra_baseband_rail_on(void)
+{
+	int ret;
+	struct board_info bi;
+	tegra_get_board_info(&bi);
+
+	/* only applicable to enterprise */
+	if (bi.board_id != BOARD_E1197)
+		return 0;
+
+	if (_hsic_reg_status == true)
+		return 0;
+
+	if (enterprise_hsic_reg == NULL) {
+		enterprise_hsic_reg = regulator_get(NULL, "avdd_hsic");
+		if (IS_ERR_OR_NULL(enterprise_hsic_reg)) {
+			pr_err("xmm: could not get regulator vddio_hsic\n");
+			enterprise_hsic_reg = NULL;
+			return PTR_ERR(enterprise_hsic_reg);
+		}
+	}
+	ret = regulator_enable(enterprise_hsic_reg);
+	if (ret < 0) {
+		pr_err("xmm: failed to enable regulator\n");
+		return ret;
+	}
+	_hsic_reg_status = true;
+	return 0;
+}
+
+static int tegra_baseband_rail_off(void)
+{
+	int ret;
+	struct board_info bi;
+	tegra_get_board_info(&bi);
+
+	/* only applicable to enterprise */
+	if (bi.board_id != BOARD_E1197)
+		return 0;
+
+	if (_hsic_reg_status == false)
+		return 0;
+
+	if (IS_ERR_OR_NULL(enterprise_hsic_reg)) {
+		pr_err("xmm: unbalanced disable on vddio_hsic regulator\n");
+		enterprise_hsic_reg = NULL;
+		return PTR_ERR(enterprise_hsic_reg);
+	}
+	ret = regulator_disable(enterprise_hsic_reg);
+	if (ret < 0) {
+		pr_err("xmm: failed to disable regulator\n");
+		return ret;
+	}
+	_hsic_reg_status = false;
+	return 0;
+}
+
 static int baseband_modem_power_on(struct baseband_power_platform_data *data)
 {
 	/* set IPC_HSIC_ACTIVE active */
@@ -146,6 +206,8 @@ static int baseband_xmm_power_on(struct platform_device *device)
 	if (baseband_xmm_powerstate != BBXMM_PS_UNINIT)
 		return -EINVAL;
 
+	tegra_baseband_rail_on();
+
 	/* reset the state machine */
 	baseband_xmm_powerstate = BBXMM_PS_INIT;
 	modem_sleep_flag = false;
@@ -245,6 +307,8 @@ static int baseband_xmm_power_off(struct platform_device *device)
 	spin_unlock_irqrestore(&xmm_lock, flags);
 	/* start registration process once again on xmm on */
 	register_hsic_device = true;
+
+	tegra_baseband_rail_off();
 	pr_debug("%s }\n", __func__);
 
 	return 0;
@@ -358,6 +422,10 @@ void baseband_xmm_set_power_status(unsigned int status)
 			}
 		}
 		pr_info("L3\n");
+		/* system is going to suspend */
+		if (baseband_xmm_powerstate == BBXMM_PS_L2)
+			tegra_baseband_rail_off();
+
 		baseband_xmm_powerstate = status;
 		spin_lock_irqsave(&xmm_lock, flags);
 		system_suspending = false;
@@ -383,6 +451,12 @@ void baseband_xmm_set_power_status(unsigned int status)
 		}
 		baseband_xmm_powerstate = status;
 		break;
+	case BBXMM_PS_L3TOL0:
+		/* poweron rail for L3 -> L0 (system resume) */
+		pr_debug("L3 -> L0, turning on power rail.\n");
+		tegra_baseband_rail_on();
+		baseband_xmm_powerstate = status;
+		break;
 	default:
 		baseband_xmm_powerstate = status;
 		break;