wip: efi stub

Make tegra UART, Device detection framework accesible for all devices

drivers/firmware/efi/libstub/efi-stub.c

@@ -140,6 +140,12 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	enum winrt_device_names winrt_device = unknown_device;
 	int i;
 
+	u8 buf_recv[4];
+	u8 buf_send = 0;
+	u32 size = 1;
+	u8 address = 0x48;
+	u8 tmp;
+
 	efi_system_table = sys_table_arg;
 
 	/* Check if we were booted by the EFI firmware */
@@ -152,6 +158,26 @@ efi_status_t __efiapi efi_pe_entry(efi_handle_t handle,
 	if (status != EFI_SUCCESS)
 		goto fail;
 
+/*
+	for (i = 0; i < 256; i++) {
+		if (i % 16 == 0) {
+			efi_printk("\n");
+			efi_printk("%02x: ", i);
+		}
+
+		i2c_recv_buf_small(buf_recv, size, 0, address, i);
+		efi_printk("%02x ", buf_recv[0]);
+	}
+
+	while(true) {
+		i2c_recv_buf_small(buf_recv, size, 0, address, buf_send);
+		if (tmp != buf_recv[0]) {
+			tmp = buf_recv[0];
+			efi_info("first byte: %04x\n", tmp);
+		}
+	}
+*/
+
 	/*
 	 * Figure out on which Windows RT device is booted.
 	 */
@@ -423,3 +449,86 @@ void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
 		++*count;
 	}
 }
+
+////////////////////////////////////////////////////////////////////////////////
+/////////////////////////////////////  I2C  ////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+
+#define vu32 volatile u32
+
+static void _i2c_wait(vu32 *base)
+{
+	u32 i;
+	base[0x23] = 0x25;
+	for (i = 0; i < 20; i++)
+	{
+		if (!(base[0x23] & 1))
+			break;
+	}
+}
+
+/**
+ * @brief i2c send package
+ * Sends a package to the I2C Bus
+ * @param idx i2c controller
+ * @param x slave address
+ * @param buf data to be transmitted
+ * @param size data size
+ * @return int error code
+ */
+static int _i2c_send_pkt(u32 idx, u32 x, u8 *buf, u32 size)
+{
+	vu32 *base = (vu32 *) 0x7000d000; //i2c_addrs[idx];
+	u32 tmp = 0;
+	if (size > 4)
+		return 0;
+
+	memcpy(&tmp, buf, size);
+
+	base[1] = x << 1; //Set x (send mode). x = address + 0=write
+	base[3] = tmp; //Set value. data register
+	base[0] = (2 * size - 2) | 0x2800; //Set size and send mode.
+	_i2c_wait(base); //Kick transaction.
+
+	base[0] = (base[0] & 0xFFFFFDFF) | 0x200;
+	while (base[7] & 0x100)
+		;
+
+	if (base[7] << 28)
+		return 0;
+
+	return 1;
+}
+
+static int _i2c_recv_pkt(u32 idx, u8 *buf, u32 size, u32 x)
+{
+	vu32 *base = (vu32 *) 0x7000d000; //i2c_addrs[idx];
+	u32 tmp;
+
+	if (size > 4)
+		return 0;
+
+	base[1] = (x << 1) | 1; //Set x (recv mode).
+	base[0] = (2 * size - 2) | 0x2840; //Set size and recv mode.
+	_i2c_wait(base); //Kick transaction.
+
+	base[0] = (base[0] & 0xFFFFFDFF) | 0x200;
+	while (base[7] & 0x100)
+		;
+
+	if (base[7] << 28)
+		return 0;
+
+	tmp = base[3]; //Get value.
+	memcpy(buf, &tmp, size);
+
+	return 1;
+}
+
+int i2c_recv_buf_small(u8 *buf, u32 size, u32 idx, u32 x, u32 y)
+{
+	int res = _i2c_send_pkt(idx, x, (u8 *)&y, 1);
+	if (res)
+		res = _i2c_recv_pkt(idx, buf, size, x);
+	return res;
+}

drivers/firmware/efi/libstub/efistub.h

@@ -910,3 +910,8 @@ enum winrt_device_names winrt_setup(void);
 void tegra_uart_print(const char *string);
 void tegra_uart_init(void);
 
+/**
+ * I2C Stuff
+ */
+int i2c_recv_buf_small(u8 *buf, u32 size, u32 idx, u32 x, u32 y);
+

drivers/firmware/efi/libstub/tegra_uart.c

@@ -123,4 +123,3 @@ void tegra_uart_print(const char *string)
 		++string;
 	}
 }
-