i2c: add acquire_bus/release_bus hooks

Change-Id: I9f55bb824f264175ae5830a2853a1897e3a00139
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2470
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

headers/private/i2c/i2c.h

@@ -53,7 +53,8 @@ typedef struct {
 	status_t (*exec_command)(i2c_device cookie, i2c_op op,
 		const void *cmdBuffer, size_t cmdLength, void* dataBuffer,
 		size_t dataLength);
-
+	status_t (*acquire_bus)(i2c_device cookie);
+	void (*release_bus)(i2c_device cookie);
 } i2c_device_interface;
 
 
@@ -76,6 +77,8 @@ typedef struct {
 	status_t (*exec_command)(i2c_bus cookie, i2c_op op, i2c_addr slaveAddress,
 		const void *cmdBuffer, size_t cmdLength, void* dataBuffer,
 		size_t dataLength);
+	status_t (*acquire_bus)(i2c_bus cookie);
+	void (*release_bus)(i2c_bus cookie);
 } i2c_bus_interface;
 
 
@@ -119,12 +122,14 @@ typedef struct {
 
 	status_t (*scan_bus)(i2c_bus_cookie cookie);
 
+	status_t (*acquire_bus)(i2c_bus_cookie cookie);
+	void (*release_bus)(i2c_bus_cookie cookie);
+
 	status_t (*install_interrupt_handler)(i2c_bus_cookie cookie,
 		i2c_intr_cookie intrCookie, interrupt_handler handler, void* data);
 
 	status_t (*uninstall_interrupt_handler)(i2c_bus_cookie cookie,
 		i2c_intr_cookie intrCookie);
-
 } i2c_sim_interface;
 
 

src/add-ons/kernel/bus_managers/i2c/I2CBus.cpp

@@ -83,12 +83,31 @@ status_t
 I2CBus::Scan()
 {
 	CALLED();
-
-	fController->scan_bus(fCookie);
+	if (fController->scan_bus != NULL)
+		fController->scan_bus(fCookie);
 	return B_OK;
 }
 
 
+status_t
+I2CBus::AcquireBus()
+{
+	CALLED();
+	if (fController->acquire_bus != NULL)
+		return fController->acquire_bus(fCookie);
+	return B_OK;
+}
+
+
+void
+I2CBus::ReleaseBus()
+{
+	CALLED();
+	if (fController->release_bus != NULL)
+		fController->release_bus(fCookie);
+}
+
+
 static status_t
 i2c_init_bus(device_node *node, void **_bus)
 {
@@ -127,7 +146,7 @@ i2c_uninit_bus(void *_bus)
 }
 
 
-status_t
+static status_t
 i2c_scan_bus(void *_bus)
 {
 	I2CBus *bus = (I2CBus *)_bus;
@@ -147,6 +166,24 @@ i2c_bus_exec_command(void* _bus, i2c_op op, i2c_addr slaveAddress,
 }
 
 
+static status_t
+i2c_bus_acquire_bus(void* _bus)
+{
+	CALLED();
+	I2CBus* bus = (I2CBus*)_bus;
+	return bus->AcquireBus();
+}
+
+
+static void
+i2c_bus_release_bus(void* _bus)
+{
+	CALLED();
+	I2CBus* bus = (I2CBus*)_bus;
+	return bus->ReleaseBus();
+}
+
+
 static status_t
 std_ops(int32 op, ...)
 {
@@ -179,6 +216,8 @@ i2c_bus_interface gI2CBusModule = {
 		NULL, // rescan
 	},
 
-	i2c_bus_exec_command
+	i2c_bus_exec_command,
+	i2c_bus_acquire_bus,
+	i2c_bus_release_bus,
 };
 

src/add-ons/kernel/bus_managers/i2c/I2CDevice.cpp

@@ -39,6 +39,21 @@ I2CDevice::ExecCommand(i2c_op op, const void *cmdBuffer,
 }
 
 
+status_t
+I2CDevice::AcquireBus()
+{
+	CALLED();
+	return fBus->AcquireBus();
+}
+
+
+void
+I2CDevice::ReleaseBus()
+{
+	CALLED();
+	fBus->ReleaseBus();
+}
+
 
 static status_t
 i2c_init_device(device_node *node, void **_device)
@@ -101,6 +116,22 @@ i2c_exec_command(i2c_device _device, i2c_op op, const void *cmdBuffer,
 }
 
 
+static status_t
+i2c_acquire_bus(i2c_device _device)
+{
+	I2CDevice *device = (I2CDevice *)_device;
+	return device->AcquireBus();
+}
+
+
+static void
+i2c_release_bus(i2c_device _device)
+{
+	I2CDevice *device = (I2CDevice *)_device;
+	return device->ReleaseBus();
+}
+
+
 static status_t
 std_ops(int32 op, ...)
 {
@@ -140,4 +171,6 @@ i2c_device_interface gI2CDeviceModule = {
 		(void (*)(void *)) i2c_device_removed
 	},
 	i2c_exec_command,
+	i2c_acquire_bus,
+	i2c_release_bus,
 };

src/add-ons/kernel/bus_managers/i2c/I2CPrivate.h

@@ -51,6 +51,8 @@ public:
 			status_t			ExecCommand(i2c_op op, const void *cmdBuffer,
 									size_t cmdLength, void* dataBuffer,
 									size_t dataLength);
+			status_t			AcquireBus();
+			void				ReleaseBus();
 
 private:
 			device_node*		fNode;
@@ -73,6 +75,8 @@ public:
 			status_t			RegisterDevice(i2c_addr slaveAddress,
 									char* hid, char** cid,
 									acpi_handle acpiHandle);
+			status_t			AcquireBus();
+			void				ReleaseBus();
 
 private:
 			device_node*		fNode;

src/add-ons/kernel/bus_managers/i2c/bus_raw.cpp

@@ -87,9 +87,15 @@ i2c_bus_raw_control(void *_cookie, uint32 op, void *data, size_t length)
 				exec.buffer = buffer;
 			}
 
-			status_t status = bus->ExecCommand(exec.op, exec.addr,
+			status_t status = bus->AcquireBus();
+			if (status != B_OK)
+				return status;
+
+			status = bus->ExecCommand(exec.op, exec.addr,
 				&exec.cmdBuffer, exec.cmdLength, exec.buffer,
 				exec.bufferLength);
+			bus->ReleaseBus();
+
 			if (status != B_OK)
 				return status;
 

src/add-ons/kernel/busses/i2c/pch_i2c.cpp

@@ -370,6 +370,24 @@ scan_bus(i2c_bus_cookie cookie)
 }
 
 
+static status_t
+acquire_bus(i2c_bus_cookie cookie)
+{
+	CALLED();
+	pch_i2c_sim_info* bus = (pch_i2c_sim_info*)cookie;
+	return mutex_lock(&bus->lock);
+}
+
+
+static void
+release_bus(i2c_bus_cookie cookie)
+{
+	CALLED();
+	pch_i2c_sim_info* bus = (pch_i2c_sim_info*)cookie;
+	mutex_unlock(&bus->lock);
+}
+
+
 //	#pragma mark -
 
 
@@ -467,6 +485,7 @@ init_bus(device_node* node, void** bus_cookie)
 		goto err;
 	}
 
+	mutex_init(&bus->lock, "pch_i2c");
 	*bus_cookie = bus;
 	return status;
 
@@ -482,6 +501,7 @@ uninit_bus(void* bus_cookie)
 {
 	pch_i2c_sim_info* bus = (pch_i2c_sim_info*)bus_cookie;
 
+	mutex_destroy(&bus->lock);
 	remove_io_interrupt_handler(bus->irq,
 		(interrupt_handler)pch_i2c_interrupt_handler, bus);
 	if (bus->registersArea >= 0)
@@ -521,6 +541,8 @@ static i2c_sim_interface sPchI2cDeviceModule = {
 	set_sim,
 	exec_command,
 	scan_bus,
+	acquire_bus,
+	release_bus,
 };
 
 

src/add-ons/kernel/busses/i2c/pch_i2c.h

@@ -14,6 +14,7 @@ extern "C" {
 }
 
 #include <i2c.h>
+#include <lock.h>
 
 
 //#define TRACE_PCH_I2C
@@ -105,6 +106,7 @@ typedef struct {
 	uint32	flags;
 	int32	error;
 
+	mutex	lock;
 	status_t (*scan_bus)(i2c_bus_cookie cookie);
 } pch_i2c_sim_info;