| /* |
| * 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 <libpayload.h> |
| |
| #include "base/container_of.h" |
| #include "drivers/bus/i2c/i2c.h" |
| #include "drivers/bus/i2c/tegra.h" |
| |
| static int tegra_i2c_send_recv(TegraI2cRegs *regs, int read, |
| uint32_t *headers, int header_words, |
| uint8_t *data, int data_len) |
| { |
| while (data_len) { |
| uint32_t status = readl(®s->fifo_status); |
| int tx_empty = status & I2C_FIFO_STATUS_TX_FIFO_EMPTY_CNT_MASK; |
| tx_empty >>= I2C_FIFO_STATUS_TX_FIFO_EMPTY_CNT_SHIFT; |
| int rx_full = status & I2C_FIFO_STATUS_RX_FIFO_FULL_CNT_MASK; |
| rx_full >>= I2C_FIFO_STATUS_RX_FIFO_FULL_CNT_SHIFT; |
| |
| while (header_words && tx_empty) { |
| writel(*headers++, ®s->tx_packet_fifo); |
| header_words--; |
| tx_empty--; |
| } |
| |
| if (!header_words) { |
| if (read) { |
| while (data_len && rx_full) { |
| uint32_t word = readl(®s->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); |
| writel(word, ®s->tx_packet_fifo); |
| data_len -= todo; |
| data += sizeof(word); |
| tx_empty--; |
| } |
| } |
| } |
| |
| uint32_t transfer_status = |
| readl(®s->packet_transfer_status); |
| |
| if (transfer_status & I2C_PKT_STATUS_NOACK_ADDR) { |
| printf("%s: The address was not acknowledged.\n", |
| __func__); |
| return -1; |
| } else if (transfer_status & I2C_PKT_STATUS_NOACK_DATA) { |
| printf("%s: The data was not acknowledged.\n", |
| __func__); |
| return -1; |
| } else if (transfer_status & I2C_PKT_STATUS_ARB_LOST) { |
| printf("%s: Lost arbitration.\n", __func__); |
| return -1; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int tegra_i2c_request(TegraI2c *bus, uint8_t chip, int cont, |
| int restart, int read, void *data, int data_len) |
| { |
| TegraI2cRegs *regs = bus->regs; |
| uint32_t headers[3]; |
| |
| if (restart && cont) { |
| printf("%s: Repeat start and continue transfer are mutually " |
| "exclusive.\n", __func__); |
| return -1; |
| } |
| |
| headers[0] = (0 << IOHEADER_PROTHDRSZ_SHIFT) | |
| (1 << IOHEADER_PKTID_SHIFT) | |
| (bus->controller_id << IOHEADER_CONTROLLER_ID_SHIFT) | |
| IOHEADER_PROTOCOL_I2C | IOHEADER_PKTTYPE_REQUEST; |
| |
| headers[1] = (data_len - 1) << IOHEADER_PAYLOADSIZE_SHIFT; |
| |
| uint32_t slave_addr = (chip << 1) | (read ? 1 : 0); |
| headers[2] = IOHEADER_I2C_REQ_ADDR_MODE_7BIT | |
| (slave_addr << IOHEADER_I2C_REQ_SLAVE_ADDR_SHIFT); |
| if (read) |
| headers[2] |= IOHEADER_I2C_REQ_READ; |
| if (restart) |
| headers[2] |= IOHEADER_I2C_REQ_REPEAT_START; |
| if (cont) |
| headers[2] |= IOHEADER_I2C_REQ_CONTINUE_XFER; |
| |
| return tegra_i2c_send_recv(regs, read, headers, ARRAY_SIZE(headers), |
| data, data_len); |
| } |
| |
| static int i2c_readwrite(TegraI2c *bus, uint8_t chip, uint32_t addr, |
| int alen, uint8_t *buf, int len, int read) |
| { |
| const uint32_t max_payload = |
| (IOHEADER_PAYLOADSIZE_MASK + 1) >> IOHEADER_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; |
| } |
| |
| void i2c_init(TegraI2c *bus) |
| { |
| TegraI2cRegs *regs = bus->regs; |
| writel(I2C_CNFG_PACKET_MODE_EN, ®s->cnfg); |
| bus->initialized = 1; |
| } |
| |
| int i2c_read(I2cOps *me, uint8_t chip, uint32_t addr, |
| int addr_len, uint8_t *data, int data_len) |
| { |
| TegraI2c *bus = container_of(me, TegraI2c, ops); |
| if (!bus->initialized) |
| i2c_init(bus); |
| return i2c_readwrite(bus, chip, addr, addr_len, data, data_len, 1); |
| } |
| |
| int i2c_write(I2cOps *me, uint8_t chip, uint32_t addr, |
| int addr_len, uint8_t *data, int data_len) |
| { |
| TegraI2c *bus = container_of(me, TegraI2c, ops); |
| if (!bus->initialized) |
| i2c_init(bus); |
| return i2c_readwrite(bus, chip, addr, addr_len, data, data_len, 0); |
| } |
| |
| TegraI2c *new_tegra_i2c(void *regs, int controller_id) |
| { |
| TegraI2c *bus = xzalloc(sizeof(*bus)); |
| bus->ops.read = i2c_read; |
| bus->ops.write = i2c_write; |
| bus->regs = regs; |
| bus->controller_id = controller_id; |
| return bus; |
| } |