tpm: atmel_twi: Make compatible with DM I2C busses

Commit 302c5db ("dm: tpm: Add Driver Model support for tpm_atmel_twi
driver") converted the Atmel TWI TPM driver itself to driver model, but
kept the legacy-style i2c_write/i2c_read calls.

Commit 3e7d940 ("dm: tpm: Every TPM drivers should depends on DM_TPM")
then made DM_I2C a dependency of the driver, effectively forcing users
to turn on CONFIG_DM_I2C_COMPAT to get it to work.

This patch adds the necessary dm_i2c_write/dm_i2c_read calls to make the
driver compatible with DM, but also keeps the legacy calls in ifdefs, so
that the driver is now compatible with both DM and non-DM setups.

Signed-off-by: Mario Six <mario.six@gdsys.cc>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Andreas Bießmann <andreas@biessmann.org>

drivers/tpm/Kconfig

@@ -15,7 +15,7 @@ config TPM_TIS_SANDBOX
 
 config TPM_ATMEL_TWI
 	bool "Enable Atmel TWI TPM device driver"
-	depends on TPM && DM_I2C
+	depends on TPM
 	help
 	  This driver supports an Atmel TPM device connected on the I2C bus.
 	  The usual tpm operations and the 'tpm' command can be used to talk

drivers/tpm/tpm_atmel_twi.c

@@ -81,14 +81,23 @@ static int tpm_atmel_twi_xfer(struct udevice *dev,
 	print_buffer(0, (void *)sendbuf, 1, send_size, 0);
 #endif
 
+#ifndef CONFIG_DM_I2C
 	res = i2c_write(0x29, 0, 0, (uchar *)sendbuf, send_size);
+#else
+	res = dm_i2c_write(dev, 0, sendbuf, send_size);
+#endif
 	if (res) {
 		printf("i2c_write returned %d\n", res);
 		return -1;
 	}
 
 	start = get_timer(0);
-	while ((res = i2c_read(0x29, 0, 0, recvbuf, 10))) {
+#ifndef CONFIG_DM_I2C
+	while ((res = i2c_read(0x29, 0, 0, recvbuf, 10)))
+#else
+	while ((res = dm_i2c_read(dev, 0, recvbuf, 10)))
+#endif
+	{
 		/* TODO Use TIS_TIMEOUT from tpm_tis_infineon.h */
 		if (get_timer(start) > ATMEL_TPM_TIMEOUT_MS) {
 			puts("tpm timed out\n");
@@ -99,7 +108,11 @@ static int tpm_atmel_twi_xfer(struct udevice *dev,
 	if (!res) {
 		*recv_len = get_unaligned_be32(recvbuf + 2);
 		if (*recv_len > 10)
+#ifndef CONFIG_DM_I2C
 			res = i2c_read(0x29, 0, 0, recvbuf, *recv_len);
+#else
+			res = dm_i2c_read(dev, 0, recvbuf, *recv_len);
+#endif
 	}
 	if (res) {
 		printf("i2c_read returned %d (rlen=%d)\n", res, *recv_len);