Support GPIO Physical Presence Detect Devices

This commit makes the necessary changes to support the GPIO devices
used for physical presence detection:
- New attribute GPIO_INFO_PHYS_PRES
- Enable GPIO Device Driver by default
- GPIO Device Driver updated to support new device type
- Added new GPIO PCA9551 layer to sit on top of GPIO Device Driver

Change-Id: I952007503eb5d9fe873adea2eaaeccff21ae18a6
RTC:211220
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/84655
Reviewed-by: Ilya Smirnov <ismirno@us.ibm.com>
Reviewed-by: Christopher J Engel <cjengel@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Nicholas E Bofferding <bofferdn@us.ibm.com>

8 files changed, 592 insertions, 20 deletions

diff --git a/src/include/usr/gpio/gpioddreasoncodes.H b/src/include/usr/gpio/gpioddreasoncodes.H
index 20ad10002..d794ff470 100644
--- a/src/include/usr/gpio/gpioddreasoncodes.H
+++ b/src/include/usr/gpio/gpioddreasoncodes.H
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2014                             */
+/* Contributors Listed Below - COPYRIGHT 2014,2019                        */
 /* [+] Google Inc.                                                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
@@ -40,10 +40,13 @@ namespace GPIO
         GPIO_READ           = 0x01,
         GPIO_WRITE          = 0x02,
         GPIO_READATTRIBUTES = 0x03,
+
+        // Use 0x10-0x1F range for PCA9551 functions
+        GPIO_PCA9551_SET_LED = 0x10,
     };
 
     /**
-     * @enum grioReasonCode
+     * @enum gpioReasonCode
      */
     enum gpioReasonCode
     {
@@ -51,6 +54,9 @@ namespace GPIO
         GPIO_ATTR_INFO_NOT_FOUND        = GPIO_COMP_ID | 0x01,
         GPIO_I2C_TARGET_NOT_FOUND       = GPIO_COMP_ID | 0x02,
         GPIO_INVALID_OP                 = GPIO_COMP_ID | 0x03,
+
+        // Use 0x10-0x1F range for PCA9551 functions
+        GPIO_PCA9551_DATA_MISMATCH      = GPIO_COMP_ID | 0x10,
     };
 
 };
diff --git a/src/include/usr/gpio/gpioif.H b/src/include/usr/gpio/gpioif.H
index 03a5a9a89..2a010039b 100644
--- a/src/include/usr/gpio/gpioif.H
+++ b/src/include/usr/gpio/gpioif.H
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2014                             */
+/* Contributors Listed Below - COPYRIGHT 2014,2019                        */
 /* [+] Google Inc.                                                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
@@ -26,6 +26,8 @@
 #ifndef __GPIOIF_H
 #define __GPIOIF_H
 
+#include <errl/errlentry.H>
+
 namespace GPIO
 {
 /**
@@ -33,10 +35,125 @@ namespace GPIO
  */
 enum gpioDevice_t
 {
-    PCA95X_GPIO = 0,
+                                // Corresponds to attribute ...
+    PCA95X_GPIO            = 0, // GPIO_INFO
+    PCA9551_GPIO_PHYS_PRES = 1, // GPIO_INFO_PHYS_PRES
     INVALID_GPIO,
 };
 
 
+/* The following enums and interfaces are specific to PCA9551 GPIO Devices.
+ * Documentation here: https://www.nxp.com/docs/en/data-sheet/PCA9551.pdf
+ */
+
+/**
+ * @brief Specific to PCA9551: LED Bit Mask to match how their status is read
+ *        back from LED "INPUT" register on PCA9551 Devices
+ */
+enum PCA9551_LEDS_t : uint8_t
+{
+    PCA9551_LED0            = 0x01,
+    PCA9551_LED1            = 0x02,
+    PCA9551_LED2            = 0x04,
+    PCA9551_LED3            = 0x08,
+    PCA9551_LED4            = 0x10,
+    PCA9551_LED5            = 0x20,
+    PCA9551_LED6            = 0x40,
+    PCA9551_LED7            = 0x80,
+};
+
+/**
+ * @brief Specific to PCA9551: Values used by the LED select registers
+ *        to determine the source of the LED data.
+ */
+enum PCA9551_LED_Output_Settings_t : uint8_t
+{
+    PCA9551_OUTPUT_LOW            = 0x00, // LED on
+    PCA9551_OUTPUT_HIGH_IMPEDANCE = 0x01, // LED off; default
+    PCA9551_OUTPUT_PWM0           = 0x02, // Output blinks at PWM0 rate
+    PCA9551_OUTPUT_PWM1           = 0x03, // Output blinks at PWM1 rate
+};
+
+/**
+ * @brief Specific to PCA9551: Control register definition:
+          sepcificies which register the operation will target
+ */
+enum PCA9551_Registers_t : uint8_t
+{
+    PCA9551_REGISTER_INPUT = 0x00, // INPUT (read only) input register
+    PCA9551_REGISTER_PCS0  = 0x01, // PSC0 (r/w) frequency prescaler 0
+    PCA9551_REGISTER_PWM0  = 0x02, // PWM0 (r/w) PWM register 0
+    PCA9551_REGISTER_PCS1  = 0x03, // PSC1 (r/w) frequency prescaler 1
+    PCA9551_REGISTER_PWM1  = 0x04, // PWM1 (r/w) PWM register 1
+    PCA9551_REGISTER_LS0   = 0x05, // LS0  (r/w) LED0 to LED3 selector
+    PCA9551_REGISTER_LS1   = 0x06, // LS1  (r/w) LED4 to LED7 selector
+};
+
+/**
+ * @brief Specific to PCA9551: Helper constants to work with the bits in the
+ *        PCA9551 registers
+ */
+enum PCA9551_Constants_t : uint8_t
+{
+    // Mask shifted to apply 2-bit settings to a specific LED in the output
+    // settings register
+    PCA9551_LED_SETTINGS_MASK = 0x03,
+
+    // Amount to shift the LED value per LED when walking through the LEDs
+    // in the INPUT register (related to PCA9551_LEDS_t above)
+    PCA9551_LED_SHIFT_AMOUNT = 0x01,
+
+    // Amount to shift the LED Settings MASK per LED when walking through the
+    // LEDs in the output settings register (ie, 2 bits at a time)
+    PCA9551_LED_SETTINGS_MASK_SHIFT_AMOUNT = 0x02,
+
+    // LED Divider: While the INPUT register can contain all 8 LED values
+    // (since each value is represented by one bit), the SETTINGS registers
+    // (PCA9551_REGISTER_LS0 and PCA9551_REGISTER_LS1) can only cover 4 LEDs
+    // each since each setting requires 2 bits.
+    // This divisor takes LEDs 4 to 7 and makes them look like LEDs 0 to 3
+    PCA9551_LED_SETTINGS_DIVISOR = 0x80,
+};
+
+/**
+ * @brief Returns the PCA9551 Device's INPUT register which reflects the state
+ *        of the device's LEDs (aka pins)
+ *
+ * @param[in] i_target - Target that contains ATTR_GPIO_INFO_PHYS_PRES attribute
+ *                       to run the commands against
+ *
+ * @param[out] o_led_data - The INPUT register data from the device
+ *
+ * @return errlHndl_t nullptr on success; non-nullptr on error.
+ */
+errlHndl_t gpioPca9551GetLeds(TARGETING::Target * i_target,
+                              uint8_t & o_led_data);
+
+/**
+ * @brief Sets the given LED (aka pin) of a PCA9551 Device to a certain setting
+ *        and returns the INPUT register which reflects the state of device's
+ *        LEDs (aka pins) after the setting has been run
+ *
+ * @param[in] i_target - Target that contains ATTR_GPIO_INFO_PHYS_PRES attribute
+ *                       to run the commands against
+ *
+ * @param[in] i_led - The specific LED Target that contains ATTR_GPIO_INFO_PHYS_PRES attribute
+ *                       to run the commands against
+ *
+ * @param[in] i_setting - the output setting to set the LED to
+ *
+ * @param[out] o_led_data - The INPUT register data from the device after the
+ *                          'set' procedure has been run allowing the caller to
+ *                          evaluate if the set actually went through
+ *
+ * @return errlHndl_t nullptr on success; non-nullptr on error.
+ */
+
+errlHndl_t gpioPca9551SetLed(TARGETING::Target * i_target,
+                             const PCA9551_LEDS_t i_led,
+                             const PCA9551_LED_Output_Settings_t i_setting,
+                             uint8_t & o_led_data);
+
+
 }; // GPIO NAMESPACE
 #endif
diff --git a/src/usr/gpio/HBconfig b/src/usr/gpio/HBconfig
index e5f650eb9..20ed72dd0 100644
--- a/src/usr/gpio/HBconfig
+++ b/src/usr/gpio/HBconfig
@@ -1,4 +1,4 @@
 config GPIODD
-    default n
+    default y
     help
         Enable GPIO device driver support
diff --git a/src/usr/gpio/gpio_pca9551.C b/src/usr/gpio/gpio_pca9551.C
new file mode 100644
index 000000000..2bc4b955b
--- /dev/null
+++ b/src/usr/gpio/gpio_pca9551.C
@@ -0,0 +1,343 @@
+/* IBM_PROLOG_BEGIN_TAG                                                   */
+/* This is an automatically generated prolog.                             */
+/*                                                                        */
+/* $Source: src/usr/gpio/gpio_pca9551.C $                                 */
+/*                                                                        */
+/* OpenPOWER HostBoot Project                                             */
+/*                                                                        */
+/* Contributors Listed Below - COPYRIGHT 2019                             */
+/* [+] International Business Machines Corp.                              */
+/*                                                                        */
+/*                                                                        */
+/* Licensed under the Apache License, Version 2.0 (the "License");        */
+/* you may not use this file except in compliance with the License.       */
+/* You may obtain a copy of the License at                                */
+/*                                                                        */
+/*     http://www.apache.org/licenses/LICENSE-2.0                         */
+/*                                                                        */
+/* Unless required by applicable law or agreed to in writing, software    */
+/* distributed under the License is distributed on an "AS IS" BASIS,      */
+/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or        */
+/* implied. See the License for the specific language governing           */
+/* permissions and limitations under the License.                         */
+/*                                                                        */
+/* IBM_PROLOG_END_TAG                                                     */
+/**
+ * @file gpio_pca9551.C
+ *
+ * @brief Implements Interfaces Specific to the PCA9551 GPIO Devices
+ *
+ * @note  Reference: https://www.nxp.com/docs/en/data-sheet/PCA9551.pdf
+ *
+ */
+
+
+#include <trace/interface.H>
+#include <errl/errlentry.H>
+#include <errl/errlmanager.H>
+#include <errl/errludtarget.H>
+#include <errl/errludstring.H>
+#include <targeting/common/targetservice.H>
+#include <targeting/common/commontargeting.H>
+#include <devicefw/driverif.H>
+#include "gpiodd.H"
+#include <gpio/gpioddreasoncodes.H>
+#include <gpio/gpioif.H>
+#include <config.h>
+
+extern trace_desc_t* g_trac_gpio;
+
+// Set to TRACFCOMP to enble unit race
+#define TRACUCOMP(args...)  TRACDCOMP(args)
+
+using namespace DeviceFW;
+using namespace TARGETING;
+
+namespace GPIO
+{
+
+
+void gpioPca9551SetReigsterHelper(const PCA9551_LEDS_t i_led,
+                                  const PCA9551_LED_Output_Settings_t i_setting,
+                                  uint8_t & io_led_register_data)
+{
+   uint8_t l_led = i_led;
+   uint8_t l_mask = PCA9551_LED_SETTINGS_MASK; // 2-bit mask shifted over to
+                                               // match i_led's value
+   uint8_t l_setting = i_setting; // will be shifted with 2-bit mask before it is applied
+
+   // Adjust values for LEDs 4 to 7 to match calculations below for LEDs 0 to 3
+   if (i_led > PCA9551_LED3)
+   {
+       l_led = l_led / PCA9551_LED_SETTINGS_DIVISOR;
+   }
+   TRACUCOMP(g_trac_gpio, "gpioPca9551SetReigsterHelper: "
+             "i_led=0x%.2X, l_led=0x%.2X, l_mask=0x%.2X, "
+             "l_setting=0x%.2X, data0=0x%.2X",
+             i_led, l_led, l_mask, l_setting,io_led_register_data);
+
+   // Move 2-bit mask and setting to cover the correct values
+   // Setting register is uint8_t broken into 4 2-bit setting sections:
+   // [LED3 Setting][LED2 Setting][LED1 Setting][LED0 Setting]
+   // --OR--
+   // [LED7 Setting][LED6 Setting][LED5 Setting][LED4 Setting]
+
+   const uint8_t match = 0x01; // shift values until l_led == match
+
+   // l_led must be >= match or following loop won't work
+   assert(l_led >= match, "gpioPca9551SetReigsterHelper: l_led %d is < match %d", l_led, match);
+
+   TRACUCOMP(g_trac_gpio,"gpioPca9551SetReigsterHelper: Pre-loop: "
+             "l_led=0x%.2X, match=0x%.2X",
+             l_led, match);
+   while ( match != l_led )
+   {
+       l_led = l_led >> PCA9551_LED_SHIFT_AMOUNT;
+       l_mask = l_mask << PCA9551_LED_SETTINGS_MASK_SHIFT_AMOUNT;
+       l_setting = l_setting << PCA9551_LED_SETTINGS_MASK_SHIFT_AMOUNT;
+       TRACUCOMP(g_trac_gpio,"gpioPca9551SetReigsterHelper: inside-loop: "
+                 "l_led=0x%.2X, l_mask=0x%.2X, l_setting=0x%.2X",
+                 l_led, l_mask, l_setting);
+   }
+   TRACUCOMP(g_trac_gpio, "gpioPca9551SetReigsterHelper: Post-loop: "
+             "l_mask=0x%.2X, l_setting=0x%.2X",
+             l_mask, l_setting);
+
+   // Apply Mask to Register data and then OR-in setting bits
+   io_led_register_data = (io_led_register_data & ~l_mask) | l_setting;
+   TRACUCOMP(g_trac_gpio, "gpioPca9551SetReigsterHelper: "
+             "io_led_register_data=0x%.2X",
+             io_led_register_data);
+
+   return;
+}
+
+
+errlHndl_t gpioPca9551GetLeds(TARGETING::Target * i_target,
+                              uint8_t & o_led_data)
+{
+    errlHndl_t err = nullptr;
+
+    TRACUCOMP(g_trac_gpio, ENTER_MRK"gpioPca9551GetLeds: "
+              "i_target 0x%.08X",
+              get_huid(i_target));
+
+    do
+    {
+
+    // Read PCA9551 INPUT Register to get Pin (aka LED) Values
+    uint8_t data = 0;
+    size_t data_len = sizeof(data);
+    const size_t exp_data_len = data_len;
+    uint64_t device_type = PCA9551_GPIO_PHYS_PRES;
+    uint64_t register_addr = PCA9551_REGISTER_INPUT;
+
+    err = DeviceFW::deviceOp
+            ( DeviceFW::READ,
+              i_target,
+              &data,
+              data_len,
+              DEVICE_GPIO_ADDRESS(device_type, register_addr)
+             );
+    if(err)
+    {
+        TRACFCOMP(g_trac_gpio, ERR_MRK"gpioPca9551GetLeds: "
+                  "Reading INPUT register failed");
+        break;
+    }
+    else
+    {
+        o_led_data = data;
+        TRACUCOMP(g_trac_gpio, INFO_MRK"gpioPca9551GetLeds: "
+                  "register_addr=0x%X, o_led_data=0x%.2X",
+                  register_addr, o_led_data);
+    }
+    assert(data_len==exp_data_len, "gpioPca9551GetLeds: expected %d size of data but got %d", exp_data_len, data_len);
+
+    } while (0);
+
+    if (err)
+    {
+        err->collectTrace( GPIO_COMP_NAME );
+    }
+
+    return err;
+}
+
+errlHndl_t gpioPca9551SetLed(TARGETING::Target * i_target,
+                             const PCA9551_LEDS_t i_led,
+                             const PCA9551_LED_Output_Settings_t i_setting,
+                             uint8_t & o_led_data)
+{
+    errlHndl_t err = nullptr;
+
+    TRACUCOMP(g_trac_gpio, ENTER_MRK"gpioPca9551SetLed: "
+              "i_target 0x%.8X, i_led=0x%.2X, i_setting=0x%.2X",
+              get_huid(i_target), i_led, i_setting);
+
+    do
+    {
+    uint64_t deviceType = PCA9551_GPIO_PHYS_PRES;
+
+    // First Read Select Register - either LS0 (LEDs 0-3) or LS1 (LEDs 4-7)
+    uint64_t register_addr = PCA9551_REGISTER_LS0;
+    if (i_led > PCA9551_LED3)
+    {
+       register_addr = PCA9551_REGISTER_LS1;
+    }
+    uint8_t data = 0;
+    size_t data_len = sizeof(data);
+    const size_t exp_data_len = data_len;
+
+    err = DeviceFW::deviceOp
+            ( DeviceFW::READ,
+              i_target,
+              &data,
+              data_len,
+              DEVICE_GPIO_ADDRESS(deviceType, register_addr)
+             );
+    if(err)
+    {
+        TRACFCOMP(g_trac_gpio, ERR_MRK"gpioPca9551SetLed: "
+                  "Reading LED Select register 0x%X failed",
+                  register_addr);
+        break;
+    }
+    else
+    {
+        TRACUCOMP(g_trac_gpio, INFO_MRK"gpioPca9551SetLed: "
+                  "LED Select register_addr=0x%X, data=0x%.2X",
+                  register_addr, data);
+    }
+    assert(data_len==exp_data_len, "gpioPca9551SetLed: expected %d size of data but got %d", exp_data_len, data_len);
+
+
+    // Create Setting Register to Write Back:
+    uint8_t write_data = data;
+    gpioPca9551SetReigsterHelper(i_led, i_setting, write_data);
+
+    // Write LED Select Register
+    data = write_data;
+
+    err = DeviceFW::deviceOp
+            ( DeviceFW::WRITE,
+              i_target,
+              &data,
+              data_len,
+              DEVICE_GPIO_ADDRESS(deviceType, register_addr)
+             );
+    if(err)
+    {
+        TRACFCOMP(g_trac_gpio, ERR_MRK"gpioPca9551SetLed: "
+                  "Writing LED Select register 0x%X failed",
+                  register_addr);
+        break;
+    }
+    else
+    {
+        TRACUCOMP(g_trac_gpio, INFO_MRK"gpioPca9551SetLed: "
+                  "Writing LED Select register_addr=0x%X, data=0x%.2X",
+                  register_addr, data);
+    }
+    assert(data_len==exp_data_len, "gpioPca9551SetLed: expected %d size of data but got %d", exp_data_len, data_len);
+
+
+    // Read Back LED Select Register
+    data = 0;
+    err = DeviceFW::deviceOp
+            ( DeviceFW::READ,
+              i_target,
+              &data,
+              data_len,
+              DEVICE_GPIO_ADDRESS(deviceType, register_addr)
+             );
+    if(err)
+    {
+        TRACFCOMP(g_trac_gpio, ERR_MRK"gpioPca9551SetLed: "
+                  "Reading LED Select register 0x%X failed",
+                  register_addr);
+        break;
+    }
+    else
+    {
+        TRACUCOMP(g_trac_gpio, INFO_MRK"gpioPca9551SetLed: "
+                  "LED Select register_addr=0x%X, data=0x%.2X",
+                  register_addr, data);
+    }
+    assert(data_len==exp_data_len, "gpioPca9551SetLed: expected %d size of data but got %d", exp_data_len, data_len);
+
+    // Compare data written and data read back
+    if (data != write_data)
+    {
+        TRACFCOMP(g_trac_gpio, ERR_MRK"gpioPca9551SetLed: "
+                  "Reading Back LED Select register 0x%X had unexpected data=",
+                  "0x%.2X. Expected 0x%.2X",
+                  register_addr, data, write_data);
+
+        /*@
+         * @errortype
+         * @reasoncode       GPIO_PCA9551_DATA_MISMATCH
+         * @severity         ERRORLOG::ERRL_SEV_UNRECOVERABLE
+         * @moduleid         GPIO_PCA9551_SET_LED
+         * @userdata1[0:31]  HUID of Master Processor Target
+         * @userdata1[32:63] Input LED to Set
+         * @userdata2[0:31]  Expected Data (aka data written)
+         * @userdata2[32:63] Data Read Back
+         * @devdesc          Setting of LED value did not appear to work
+         * @custdesc         A problem occurred during the IPL
+         *                   of the system.
+         */
+        err = new ERRORLOG::ErrlEntry(ERRORLOG::ERRL_SEV_UNRECOVERABLE,
+                                      GPIO_PCA9551_SET_LED,
+                                      GPIO_PCA9551_DATA_MISMATCH,
+                                      TWO_UINT32_TO_UINT64(
+                                        get_huid(i_target),
+                                        i_led),
+                                      TWO_UINT32_TO_UINT64(
+                                        write_data,
+                                        data),
+                                      ERRORLOG::ErrlEntry::ADD_SW_CALLOUT);
+
+        break;
+    }
+
+    // Read PCA9551 INPUT Register to get Pin (aka LED) Values
+    data = 0;
+    data_len = sizeof(data);
+    register_addr = PCA9551_REGISTER_INPUT;
+
+    err = DeviceFW::deviceOp
+            ( DeviceFW::READ,
+              i_target,
+              &data,
+              data_len,
+              DEVICE_GPIO_ADDRESS(deviceType, register_addr)
+             );
+    if(err)
+    {
+        TRACFCOMP(g_trac_gpio, ERR_MRK"gpioPca9551SetLed: "
+                  "Reading INPUT register failed");
+        break;
+    }
+    else
+    {
+        o_led_data = data;
+        TRACUCOMP(g_trac_gpio, INFO_MRK"gpioPca9551SetLed: "
+                  "INPUT register_addr=0x%X, o_led_data=0x%.2X",
+                  register_addr, o_led_data);
+    }
+    assert(data_len==exp_data_len, "gpioPca9551SetLed: expected %d size of data but got %d", exp_data_len, data_len);
+
+    } while (0);
+
+    if (err)
+    {
+        err->collectTrace( GPIO_COMP_NAME );
+    }
+
+    return err;
+
+}
+
+}; // end namespace GPIO
+
diff --git a/src/usr/gpio/gpiodd.C b/src/usr/gpio/gpiodd.C
index 559dab79e..69cde2b70 100644
--- a/src/usr/gpio/gpiodd.C
+++ b/src/usr/gpio/gpiodd.C
@@ -5,7 +5,7 @@
 /*                                                                        */
 /* OpenPOWER HostBoot Project                                             */
 /*                                                                        */
-/* Contributors Listed Below - COPYRIGHT 2014,2018                        */
+/* Contributors Listed Below - COPYRIGHT 2014,2019                        */
 /* [+] Google Inc.                                                        */
 /* [+] International Business Machines Corp.                              */
 /*                                                                        */
@@ -34,6 +34,8 @@
 #include <devicefw/driverif.H>
 #include "gpiodd.H"
 #include <gpio/gpioddreasoncodes.H>
+#include <gpio/gpioif.H>
+#include <config.h>
 
 trace_desc_t * g_trac_gpio = NULL;
 TRAC_INIT( & g_trac_gpio, GPIO_COMP_NAME, KILOBYTE );
@@ -57,6 +59,11 @@ DEVICE_REGISTER_ROUTE( DeviceFW::WILDCARD,
                        TARGETING::TYPE_MEMBUF,
                        gpioPerformOp);
 
+DEVICE_REGISTER_ROUTE( DeviceFW::WILDCARD,
+                       DeviceFW::GPIO,
+                       TARGETING::TYPE_PROC,
+                       gpioPerformOp);
+
 errlHndl_t gpioPerformOp(DeviceFW::OperationType i_opType,
                          TARGETING::Target * i_target,
                          void * io_buffer,
@@ -70,7 +77,8 @@ errlHndl_t gpioPerformOp(DeviceFW::OperationType i_opType,
     gpioInfo.deviceType = va_arg( i_args, uint64_t );
     gpioInfo.portAddr   = va_arg( i_args, uint64_t );
 
-    TRACDCOMP(g_trac_gpio, ENTER_MRK"gpioPerformOp(): "
+//MAB make TRACD
+    TRACFCOMP(g_trac_gpio, ENTER_MRK"gpioPerformOp(): "
               "optype %d deviceType %d portAddr %d",
               i_opType, gpioInfo.deviceType, gpioInfo.portAddr);
 
@@ -237,20 +245,51 @@ errlHndl_t gpioReadAttributes ( TARGETING::Target * i_target,
 {
     errlHndl_t err = NULL;
 
-    TARGETING::GpioInfo gpioData;
-
     bool attrReadErr = false;
 
+#ifndef CONFIG_FSP_BUILD
+    TARGETING::GpioInfo gpioData;
+#endif
+    TARGETING::GpioInfoPhysPres gpioDataPhysPres;
 
     switch(io_gpioInfo.deviceType)
     {
+#ifndef CONFIG_FSP_BUILD
         case PCA95X_GPIO:
             if( !( i_target->
                    tryGetAttr<TARGETING::ATTR_GPIO_INFO>( gpioData ) ) )
             {
                 attrReadErr = true;
             }
+            else
+            {
+                io_gpioInfo.i2cMasterPath = gpioData.i2cMasterPath;
+                io_gpioInfo.engine        = gpioData.engine;
+                io_gpioInfo.i2cPort       = gpioData.port;
+                io_gpioInfo.i2cDeviceAddr = gpioData.devAddr;
+                io_gpioInfo.i2cMuxBusSelector = gpioData.i2cMuxBusSelector;
+                io_gpioInfo.i2cMuxPath    = gpioData.i2cMuxPath;
+            }
             break;
+#endif
+        case PCA9551_GPIO_PHYS_PRES:
+
+            if( !( i_target->
+                   tryGetAttr<TARGETING::ATTR_GPIO_INFO_PHYS_PRES>(gpioDataPhysPres)))
+            {
+                attrReadErr = true;
+            }
+            else
+            {
+                io_gpioInfo.i2cMasterPath = gpioDataPhysPres.i2cMasterPath;
+                io_gpioInfo.engine        = gpioDataPhysPres.engine;
+                io_gpioInfo.i2cPort       = gpioDataPhysPres.port;
+                io_gpioInfo.i2cDeviceAddr = gpioDataPhysPres.devAddr;
+                io_gpioInfo.i2cMuxBusSelector = gpioDataPhysPres.i2cMuxBusSelector;
+                io_gpioInfo.i2cMuxPath    = gpioDataPhysPres.i2cMuxPath;
+            }
+            break;
+
         default:
 
             TRACFCOMP( g_trac_gpio,ERR_MRK"gpioReadAttributes() - "
@@ -309,16 +348,6 @@ errlHndl_t gpioReadAttributes ( TARGETING::Target * i_target,
         err->collectTrace( GPIO_COMP_NAME );
     }
 
-    if( !err )
-    {
-        io_gpioInfo.i2cMasterPath = gpioData.i2cMasterPath;
-        io_gpioInfo.engine        = gpioData.engine;
-        io_gpioInfo.i2cPort       = gpioData.port;
-        io_gpioInfo.i2cDeviceAddr = gpioData.devAddr;
-        io_gpioInfo.i2cMuxBusSelector = gpioData.i2cMuxBusSelector;
-        io_gpioInfo.i2cMuxPath    = gpioData.i2cMuxPath;
-    }
-
     return err;
 }
 
diff --git a/src/usr/gpio/makefile b/src/usr/gpio/makefile
index d40eaa130..fd42e2d1d 100644
--- a/src/usr/gpio/makefile
+++ b/src/usr/gpio/makefile
@@ -5,7 +5,7 @@
 #
 # OpenPOWER HostBoot Project
 #
-# Contributors Listed Below - COPYRIGHT 2014
+# Contributors Listed Below - COPYRIGHT 2014,2019
 # [+] Google Inc.
 # [+] International Business Machines Corp.
 #
@@ -27,6 +27,8 @@ ROOTPATH = ../../..
 MODULE = gpio
 
 OBJS += $(if $(CONFIG_GPIODD),gpiodd.o,)
+OBJS += $(if $(CONFIG_GPIODD),gpio_pca9551.o,)
+
 
 # no way to test this at the moment TODO RTC 111415
 #SUBDIRS = test.d
diff --git a/src/usr/targeting/common/xmltohb/attribute_types_hb.xml b/src/usr/targeting/common/xmltohb/attribute_types_hb.xml
index 3e651b498..8be123d99 100755
--- a/src/usr/targeting/common/xmltohb/attribute_types_hb.xml
+++ b/src/usr/targeting/common/xmltohb/attribute_types_hb.xml
@@ -325,6 +325,78 @@
     <hbOnly/>
   </attribute>
 
+  <attribute>
+    <id>GPIO_INFO_PHYS_PRES</id>
+    <description>Information needed to address GPIO device that corresponds
+                 to the Physical Presence Detect circuit</description>
+    <complexType>
+      <description>Structure to define the addessing for an I2C
+                     slave device.</description>
+      <field>
+        <name>i2cMasterPath</name>
+        <description>Entity path to the chip that contains the I2C
+                     master</description>
+        <type>EntityPath</type>
+        <default>physical:sys-0/node-0/proc-0</default>
+      </field>
+      <field>
+        <name>port</name>
+        <description>Port from the I2C Master device. This is a 6-bit
+                     value.</description>
+        <type>uint8_t</type>
+        <default>0</default>
+      </field>
+      <field>
+        <name>devAddr</name>
+        <description>Device address on the I2C bus. This is a 7-bit value,
+                     but then shifted 1 bit left.</description>
+        <type>uint8_t</type>
+        <default>0xC0</default>
+      </field>
+      <field>
+        <name>engine</name>
+        <description>I2C master engine. This is a 2-bit
+                     value.</description>
+        <type>uint8_t</type>
+        <default>2</default>
+      </field>
+      <field>
+        <name>windowOpenPin</name>
+        <description>Logical GPIO pin number used to open or close the physcial
+                     presence window</description>
+        <type>uint8_t</type>
+        <default>0</default>
+      </field>
+      <field>
+        <name>physicalPresencePin</name>
+        <description>Logical GPIO pin number used to determine if physical
+                     presence was asserted</description>
+        <type>uint8_t</type>
+        <default>1</default>
+      </field>
+      <!-- i2c Mux Bus Selector Definition -->
+      <field>
+        <default>0xFF</default>
+        <description>Determines which of the N selectable buses the mux
+                     will connect to. OxFF indicates no mux present
+                     or N/A.</description>
+        <name>i2cMuxBusSelector</name>
+        <type>uint8_t</type>
+      </field>
+      <!-- i2c Mux Path Definition -->
+      <field>
+        <!-- NOTE: physical:sys-0 implies that there is no mux in
+                   the bus path for this part.                     -->
+        <default>physical:sys-0</default>
+        <description>Entity path to the I2C mux for this device.</description>
+        <name>i2cMuxPath</name>
+        <type>EntityPath</type>
+      </field>
+    </complexType>
+    <persistency>non-volatile</persistency>
+    <readable/>
+  </attribute>
+
   <!-- TODO RTC 122856 When support for HB only volatile attributes with non-zero
      default is implemented, update default value to match the description,
      Until that happens, code must set the appropriate default if needed. -->
diff --git a/src/usr/targeting/common/xmltohb/target_types_hb.xml b/src/usr/targeting/common/xmltohb/target_types_hb.xml
index 26cf81f6f..080fbecae 100644
--- a/src/usr/targeting/common/xmltohb/target_types_hb.xml
+++ b/src/usr/targeting/common/xmltohb/target_types_hb.xml
@@ -116,6 +116,9 @@
       <id>FSI_SCOM_MUTEX</id>
     </attribute>
     <attribute>
+      <id>GPIO_INFO_PHYS_PRES</id>
+    </attribute>
+    <attribute>
       <id>HBRT_HYP_ID</id>
     </attribute>
     <attribute>