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Diffstat (limited to 'src/soc/nvidia/tegra/i2c.c')
-rw-r--r--src/soc/nvidia/tegra/i2c.c180
1 files changed, 180 insertions, 0 deletions
diff --git a/src/soc/nvidia/tegra/i2c.c b/src/soc/nvidia/tegra/i2c.c
new file mode 100644
index 0000000000..ddb54a56c0
--- /dev/null
+++ b/src/soc/nvidia/tegra/i2c.c
@@ -0,0 +1,180 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2013 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <arch/io.h>
+#include <console/console.h>
+#include <device/i2c.h>
+#include <stdlib.h>
+#include <string.h>
+#include <soc/addressmap.h>
+
+#include "i2c.h"
+
+static int tegra_i2c_send_recv(struct tegra_i2c_regs *regs, int read,
+ uint32_t *headers, int header_words,
+ uint8_t *data, int data_len)
+{
+ while (data_len) {
+ uint32_t status = read32(&regs->fifo_status);
+ int tx_empty =
+ status & TEGRA_I2C_FIFO_STATUS_TX_FIFO_EMPTY_CNT_MASK;
+ tx_empty >>= TEGRA_I2C_FIFO_STATUS_TX_FIFO_EMPTY_CNT_SHIFT;
+ int rx_full =
+ status & TEGRA_I2C_FIFO_STATUS_RX_FIFO_FULL_CNT_MASK;
+ rx_full >>= TEGRA_I2C_FIFO_STATUS_RX_FIFO_FULL_CNT_SHIFT;
+
+ while (header_words && tx_empty) {
+ write32(*headers++, &regs->tx_packet_fifo);
+ header_words--;
+ tx_empty--;
+ }
+
+ if (!header_words) {
+ if (read) {
+ while (data_len && rx_full) {
+ uint32_t word = read32(&regs->rx_fifo);
+ int todo = MIN(data_len, sizeof(word));
+
+ memcpy(data, &word, todo);
+ data_len -= todo;
+ data += sizeof(word);
+ rx_full--;
+ }
+ } else {
+ while (data_len && tx_empty) {
+ uint32_t word;
+ int todo = MIN(data_len, sizeof(word));
+
+ memcpy(&word, data, todo);
+ write32(word, &regs->tx_packet_fifo);
+ data_len -= todo;
+ data += sizeof(word);
+ tx_empty--;
+ }
+ }
+ }
+
+ uint32_t transfer_status =
+ read32(&regs->packet_transfer_status);
+
+ if (transfer_status & TEGRA_I2C_PKT_STATUS_NOACK_ADDR_MASK) {
+ printk(BIOS_ERR,
+ "%s: The address was not acknowledged.\n",
+ __func__);
+ return -1;
+ } else if (transfer_status &
+ TEGRA_I2C_PKT_STATUS_NOACK_DATA_MASK) {
+ printk(BIOS_ERR,
+ "%s: The data was not acknowledged.\n",
+ __func__);
+ return -1;
+ } else if (transfer_status &
+ TEGRA_I2C_PKT_STATUS_ARB_LOST_MASK) {
+ printk(BIOS_ERR,
+ "%s: Lost arbitration.\n",
+ __func__);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+static int tegra_i2c_request(int bus, unsigned chip, int cont, int restart,
+ int read, void *data, int data_len)
+{
+ struct tegra_i2c_regs * const regs = tegra_i2c_bases[bus];
+ uint32_t headers[3];
+
+ if (restart && cont) {
+ printk(BIOS_ERR, "%s: Repeat start and continue xfer are "
+ "mutually exclusive.\n", __func__);
+ return -1;
+ }
+
+ headers[0] = (0 << IOHEADER_WORD0_PROTHDRSZ_SHIFT) |
+ (1 << IOHEADER_WORD0_PKTID_SHIFT) |
+ (bus << IOHEADER_WORD0_CONTROLLER_ID_SHIFT) |
+ IOHEADER_WORD0_PROTOCOL_I2C |
+ IOHEADER_WORD0_PKTTYPE_REQUEST;
+
+ headers[1] = (data_len - 1) << IOHEADER_WORD1_PAYLOADSIZE_SHIFT;
+
+ uint32_t slave_addr = (chip << 1) | (read ? 1 : 0);
+ headers[2] = IOHEADER_I2C_REQ_ADDRESS_MODE_7BIT |
+ (slave_addr << IOHEADER_I2C_REQ_SLAVE_ADDR_SHIFT);
+ if (read)
+ headers[2] |= IOHEADER_I2C_REQ_READ_WRITE_READ;
+ else
+ headers[2] |= IOHEADER_I2C_REQ_READ_WRITE_WRITE;
+ if (restart)
+ headers[2] |= IOHEADER_I2C_REQ_REPEAT_START_STOP_START;
+ if (cont)
+ headers[2] |= IOHEADER_I2C_REQ_CONTINUE_XFER_MASK;
+
+ return tegra_i2c_send_recv(regs, read, headers, ARRAY_SIZE(headers),
+ data, data_len);
+}
+
+static int i2c_readwrite(unsigned bus, unsigned chip, unsigned addr,
+ unsigned alen, uint8_t *buf, unsigned len, int read)
+{
+ const uint32_t max_payload =
+ (IOHEADER_WORD1_PAYLOADSIZE_MASK + 1) >>
+ IOHEADER_WORD1_PAYLOADSIZE_SHIFT;
+ uint8_t abuf[sizeof(addr)];
+
+ int i;
+ for (i = 0; i < alen; i++)
+ abuf[i] = addr >> ((alen - i - 1) * 8);
+
+ if (tegra_i2c_request(bus, chip, !read, 0, 0, abuf, alen))
+ return -1;
+
+ while (len) {
+ int todo = MIN(len, max_payload);
+ int cont = (todo < len);
+ if (tegra_i2c_request(bus, chip, cont, 0, read, buf, todo)) {
+ // We should reset the controller here.
+ return -1;
+ }
+ len -= todo;
+ buf += todo;
+ }
+ return 0;
+}
+
+int i2c_read(unsigned bus, unsigned chip, unsigned addr,
+ unsigned alen, uint8_t *buf, unsigned len)
+{
+ return i2c_readwrite(bus, chip, addr, alen, buf, len, 1);
+}
+
+int i2c_write(unsigned bus, unsigned chip, unsigned addr,
+ unsigned alen, const uint8_t *buf, unsigned len)
+{
+ return i2c_readwrite(bus, chip, addr, alen, (void *)buf, len, 0);
+}
+
+void i2c_init(unsigned bus)
+{
+ struct tegra_i2c_regs * const regs = tegra_i2c_bases[bus];
+
+ write32(TEGRA_I2C_CNFG_PACKET_MODE_EN_MASK, &regs->cnfg);
+}