tegra: i2c: Add I2C driver
Add basic i2c driver for Tegra2 with 8- and 16-bit address support.
The driver requires CONFIG_OF_CONTROL to obtain its configuration
from the device tree.
(Simon Glass: sjg@chromium.org modified for upstream)
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Heiko Schocher <hs@denx.de>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/drivers/i2c/tegra_i2c.c b/drivers/i2c/tegra_i2c.c
new file mode 100644
index 0000000..21f6897
--- /dev/null
+++ b/drivers/i2c/tegra_i2c.c
@@ -0,0 +1,569 @@
+/*
+ * Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
+ * Copyright (c) 2010-2011 NVIDIA Corporation
+ * NVIDIA Corporation <www.nvidia.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <i2c.h>
+#include <asm/io.h>
+#include <asm/arch/clk_rst.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/funcmux.h>
+#include <asm/arch/gpio.h>
+#include <asm/arch/pinmux.h>
+#include <asm/arch/tegra_i2c.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static unsigned int i2c_bus_num;
+
+/* Information about i2c controller */
+struct i2c_bus {
+ int id;
+ enum periph_id periph_id;
+ int speed;
+ int pinmux_config;
+ struct i2c_control *control;
+ struct i2c_ctlr *regs;
+ int is_dvc; /* DVC type, rather than I2C */
+ int inited; /* bus is inited */
+};
+
+static struct i2c_bus i2c_controllers[TEGRA_I2C_NUM_CONTROLLERS];
+
+static void set_packet_mode(struct i2c_bus *i2c_bus)
+{
+ u32 config;
+
+ config = I2C_CNFG_NEW_MASTER_FSM_MASK | I2C_CNFG_PACKET_MODE_MASK;
+
+ if (i2c_bus->is_dvc) {
+ struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;
+
+ writel(config, &dvc->cnfg);
+ } else {
+ writel(config, &i2c_bus->regs->cnfg);
+ /*
+ * program I2C_SL_CNFG.NEWSL to ENABLE. This fixes probe
+ * issues, i.e., some slaves may be wrongly detected.
+ */
+ setbits_le32(&i2c_bus->regs->sl_cnfg, I2C_SL_CNFG_NEWSL_MASK);
+ }
+}
+
+static void i2c_reset_controller(struct i2c_bus *i2c_bus)
+{
+ /* Reset I2C controller. */
+ reset_periph(i2c_bus->periph_id, 1);
+
+ /* re-program config register to packet mode */
+ set_packet_mode(i2c_bus);
+}
+
+static void i2c_init_controller(struct i2c_bus *i2c_bus)
+{
+ /*
+ * Use PLLP - DP-04508-001_v06 datasheet indicates a divisor of 8
+ * here, in section 23.3.1, but in fact we seem to need a factor of
+ * 16 to get the right frequency.
+ */
+ clock_start_periph_pll(i2c_bus->periph_id, CLOCK_ID_PERIPH,
+ i2c_bus->speed * 2 * 8);
+
+ /* Reset I2C controller. */
+ i2c_reset_controller(i2c_bus);
+
+ /* Configure I2C controller. */
+ if (i2c_bus->is_dvc) { /* only for DVC I2C */
+ struct dvc_ctlr *dvc = (struct dvc_ctlr *)i2c_bus->regs;
+
+ setbits_le32(&dvc->ctrl3, DVC_CTRL_REG3_I2C_HW_SW_PROG_MASK);
+ }
+
+ funcmux_select(i2c_bus->periph_id, i2c_bus->pinmux_config);
+}
+
+static void send_packet_headers(
+ struct i2c_bus *i2c_bus,
+ struct i2c_trans_info *trans,
+ u32 packet_id)
+{
+ u32 data;
+
+ /* prepare header1: Header size = 0 Protocol = I2C, pktType = 0 */
+ data = PROTOCOL_TYPE_I2C << PKT_HDR1_PROTOCOL_SHIFT;
+ data |= packet_id << PKT_HDR1_PKT_ID_SHIFT;
+ data |= i2c_bus->id << PKT_HDR1_CTLR_ID_SHIFT;
+ writel(data, &i2c_bus->control->tx_fifo);
+ debug("pkt header 1 sent (0x%x)\n", data);
+
+ /* prepare header2 */
+ data = (trans->num_bytes - 1) << PKT_HDR2_PAYLOAD_SIZE_SHIFT;
+ writel(data, &i2c_bus->control->tx_fifo);
+ debug("pkt header 2 sent (0x%x)\n", data);
+
+ /* prepare IO specific header: configure the slave address */
+ data = trans->address << PKT_HDR3_SLAVE_ADDR_SHIFT;
+
+ /* Enable Read if it is not a write transaction */
+ if (!(trans->flags & I2C_IS_WRITE))
+ data |= PKT_HDR3_READ_MODE_MASK;
+
+ /* Write I2C specific header */
+ writel(data, &i2c_bus->control->tx_fifo);
+ debug("pkt header 3 sent (0x%x)\n", data);
+}
+
+static int wait_for_tx_fifo_empty(struct i2c_control *control)
+{
+ u32 count;
+ int timeout_us = I2C_TIMEOUT_USEC;
+
+ while (timeout_us >= 0) {
+ count = (readl(&control->fifo_status) & TX_FIFO_EMPTY_CNT_MASK)
+ >> TX_FIFO_EMPTY_CNT_SHIFT;
+ if (count == I2C_FIFO_DEPTH)
+ return 1;
+ udelay(10);
+ timeout_us -= 10;
+ }
+
+ return 0;
+}
+
+static int wait_for_rx_fifo_notempty(struct i2c_control *control)
+{
+ u32 count;
+ int timeout_us = I2C_TIMEOUT_USEC;
+
+ while (timeout_us >= 0) {
+ count = (readl(&control->fifo_status) & TX_FIFO_FULL_CNT_MASK)
+ >> TX_FIFO_FULL_CNT_SHIFT;
+ if (count)
+ return 1;
+ udelay(10);
+ timeout_us -= 10;
+ }
+
+ return 0;
+}
+
+static int wait_for_transfer_complete(struct i2c_control *control)
+{
+ int int_status;
+ int timeout_us = I2C_TIMEOUT_USEC;
+
+ while (timeout_us >= 0) {
+ int_status = readl(&control->int_status);
+ if (int_status & I2C_INT_NO_ACK_MASK)
+ return -int_status;
+ if (int_status & I2C_INT_ARBITRATION_LOST_MASK)
+ return -int_status;
+ if (int_status & I2C_INT_XFER_COMPLETE_MASK)
+ return 0;
+
+ udelay(10);
+ timeout_us -= 10;
+ }
+
+ return -1;
+}
+
+static int send_recv_packets(struct i2c_bus *i2c_bus,
+ struct i2c_trans_info *trans)
+{
+ struct i2c_control *control = i2c_bus->control;
+ u32 int_status;
+ u32 words;
+ u8 *dptr;
+ u32 local;
+ uchar last_bytes;
+ int error = 0;
+ int is_write = trans->flags & I2C_IS_WRITE;
+
+ /* clear status from previous transaction, XFER_COMPLETE, NOACK, etc. */
+ int_status = readl(&control->int_status);
+ writel(int_status, &control->int_status);
+
+ send_packet_headers(i2c_bus, trans, 1);
+
+ words = DIV_ROUND_UP(trans->num_bytes, 4);
+ last_bytes = trans->num_bytes & 3;
+ dptr = trans->buf;
+
+ while (words) {
+ u32 *wptr = (u32 *)dptr;
+
+ if (is_write) {
+ /* deal with word alignment */
+ if ((unsigned)dptr & 3) {
+ memcpy(&local, dptr, sizeof(u32));
+ writel(local, &control->tx_fifo);
+ debug("pkt data sent (0x%x)\n", local);
+ } else {
+ writel(*wptr, &control->tx_fifo);
+ debug("pkt data sent (0x%x)\n", *wptr);
+ }
+ if (!wait_for_tx_fifo_empty(control)) {
+ error = -1;
+ goto exit;
+ }
+ } else {
+ if (!wait_for_rx_fifo_notempty(control)) {
+ error = -1;
+ goto exit;
+ }
+ /*
+ * for the last word, we read into our local buffer,
+ * in case that caller did not provide enough buffer.
+ */
+ local = readl(&control->rx_fifo);
+ if ((words == 1) && last_bytes)
+ memcpy(dptr, (char *)&local, last_bytes);
+ else if ((unsigned)dptr & 3)
+ memcpy(dptr, &local, sizeof(u32));
+ else
+ *wptr = local;
+ debug("pkt data received (0x%x)\n", local);
+ }
+ words--;
+ dptr += sizeof(u32);
+ }
+
+ if (wait_for_transfer_complete(control)) {
+ error = -1;
+ goto exit;
+ }
+ return 0;
+exit:
+ /* error, reset the controller. */
+ i2c_reset_controller(i2c_bus);
+
+ return error;
+}
+
+static int tegra2_i2c_write_data(u32 addr, u8 *data, u32 len)
+{
+ int error;
+ struct i2c_trans_info trans_info;
+
+ trans_info.address = addr;
+ trans_info.buf = data;
+ trans_info.flags = I2C_IS_WRITE;
+ trans_info.num_bytes = len;
+ trans_info.is_10bit_address = 0;
+
+ error = send_recv_packets(&i2c_controllers[i2c_bus_num], &trans_info);
+ if (error)
+ debug("tegra2_i2c_write_data: Error (%d) !!!\n", error);
+
+ return error;
+}
+
+static int tegra2_i2c_read_data(u32 addr, u8 *data, u32 len)
+{
+ int error;
+ struct i2c_trans_info trans_info;
+
+ trans_info.address = addr | 1;
+ trans_info.buf = data;
+ trans_info.flags = 0;
+ trans_info.num_bytes = len;
+ trans_info.is_10bit_address = 0;
+
+ error = send_recv_packets(&i2c_controllers[i2c_bus_num], &trans_info);
+ if (error)
+ debug("tegra2_i2c_read_data: Error (%d) !!!\n", error);
+
+ return error;
+}
+
+#ifndef CONFIG_OF_CONTROL
+#error "Please enable device tree support to use this driver"
+#endif
+
+unsigned int i2c_get_bus_speed(void)
+{
+ return i2c_controllers[i2c_bus_num].speed;
+}
+
+int i2c_set_bus_speed(unsigned int speed)
+{
+ struct i2c_bus *i2c_bus;
+
+ i2c_bus = &i2c_controllers[i2c_bus_num];
+ i2c_bus->speed = speed;
+ i2c_init_controller(i2c_bus);
+
+ return 0;
+}
+
+static int i2c_get_config(const void *blob, int node, struct i2c_bus *i2c_bus)
+{
+ i2c_bus->regs = (struct i2c_ctlr *)fdtdec_get_addr(blob, node, "reg");
+
+ /*
+ * We don't have a binding for pinmux yet. Leave it out for now. So
+ * far no one needs anything other than the default.
+ */
+ i2c_bus->pinmux_config = FUNCMUX_DEFAULT;
+ i2c_bus->speed = fdtdec_get_int(blob, node, "clock-frequency", 0);
+ i2c_bus->periph_id = clock_decode_periph_id(blob, node);
+
+ /*
+ * We can't specify the pinmux config in the fdt, so I2C2 will not
+ * work on Seaboard. It normally has no devices on it anyway.
+ * You could add in this little hack if you need to use it.
+ * The correct solution is a pinmux binding in the fdt.
+ *
+ * if (i2c_bus->periph_id == PERIPH_ID_I2C2)
+ * i2c_bus->pinmux_config = FUNCMUX_I2C2_PTA;
+ */
+ if (i2c_bus->periph_id == -1)
+ return -FDT_ERR_NOTFOUND;
+
+ return 0;
+}
+
+/*
+ * Process a list of nodes, adding them to our list of I2C ports.
+ *
+ * @param blob fdt blob
+ * @param node_list list of nodes to process (any <=0 are ignored)
+ * @param count number of nodes to process
+ * @param is_dvc 1 if these are DVC ports, 0 if standard I2C
+ * @return 0 if ok, -1 on error
+ */
+static int process_nodes(const void *blob, int node_list[], int count,
+ int is_dvc)
+{
+ struct i2c_bus *i2c_bus;
+ int i;
+
+ /* build the i2c_controllers[] for each controller */
+ for (i = 0; i < count; i++) {
+ int node = node_list[i];
+
+ if (node <= 0)
+ continue;
+
+ i2c_bus = &i2c_controllers[i];
+ i2c_bus->id = i;
+
+ if (i2c_get_config(blob, node, i2c_bus)) {
+ printf("i2c_init_board: failed to decode bus %d\n", i);
+ return -1;
+ }
+
+ i2c_bus->is_dvc = is_dvc;
+ if (is_dvc) {
+ i2c_bus->control =
+ &((struct dvc_ctlr *)i2c_bus->regs)->control;
+ } else {
+ i2c_bus->control = &i2c_bus->regs->control;
+ }
+ debug("%s: controller bus %d at %p, periph_id %d, speed %d: ",
+ is_dvc ? "dvc" : "i2c", i, i2c_bus->regs,
+ i2c_bus->periph_id, i2c_bus->speed);
+ i2c_init_controller(i2c_bus);
+ debug("ok\n");
+ i2c_bus->inited = 1;
+
+ /* Mark position as used */
+ node_list[i] = -1;
+ }
+
+ return 0;
+}
+
+/* Sadly there is no error return from this function */
+void i2c_init_board(void)
+{
+ int node_list[TEGRA_I2C_NUM_CONTROLLERS];
+ const void *blob = gd->fdt_blob;
+ int count;
+
+ /* First get the normal i2c ports */
+ count = fdtdec_find_aliases_for_id(blob, "i2c",
+ COMPAT_NVIDIA_TEGRA20_I2C, node_list,
+ TEGRA_I2C_NUM_CONTROLLERS);
+ if (process_nodes(blob, node_list, count, 0))
+ return;
+
+ /* Now look for dvc ports */
+ count = fdtdec_add_aliases_for_id(blob, "i2c",
+ COMPAT_NVIDIA_TEGRA20_DVC, node_list,
+ TEGRA_I2C_NUM_CONTROLLERS);
+ if (process_nodes(blob, node_list, count, 1))
+ return;
+}
+
+void i2c_init(int speed, int slaveaddr)
+{
+ /* This will override the speed selected in the fdt for that port */
+ debug("i2c_init(speed=%u, slaveaddr=0x%x)\n", speed, slaveaddr);
+ i2c_set_bus_speed(speed);
+}
+
+/* i2c write version without the register address */
+int i2c_write_data(uchar chip, uchar *buffer, int len)
+{
+ int rc;
+
+ debug("i2c_write_data: chip=0x%x, len=0x%x\n", chip, len);
+ debug("write_data: ");
+ /* use rc for counter */
+ for (rc = 0; rc < len; ++rc)
+ debug(" 0x%02x", buffer[rc]);
+ debug("\n");
+
+ /* Shift 7-bit address over for lower-level i2c functions */
+ rc = tegra2_i2c_write_data(chip << 1, buffer, len);
+ if (rc)
+ debug("i2c_write_data(): rc=%d\n", rc);
+
+ return rc;
+}
+
+/* i2c read version without the register address */
+int i2c_read_data(uchar chip, uchar *buffer, int len)
+{
+ int rc;
+
+ debug("inside i2c_read_data():\n");
+ /* Shift 7-bit address over for lower-level i2c functions */
+ rc = tegra2_i2c_read_data(chip << 1, buffer, len);
+ if (rc) {
+ debug("i2c_read_data(): rc=%d\n", rc);
+ return rc;
+ }
+
+ debug("i2c_read_data: ");
+ /* reuse rc for counter*/
+ for (rc = 0; rc < len; ++rc)
+ debug(" 0x%02x", buffer[rc]);
+ debug("\n");
+
+ return 0;
+}
+
+/* Probe to see if a chip is present. */
+int i2c_probe(uchar chip)
+{
+ int rc;
+ uchar reg;
+
+ debug("i2c_probe: addr=0x%x\n", chip);
+ reg = 0;
+ rc = i2c_write_data(chip, ®, 1);
+ if (rc) {
+ debug("Error probing 0x%x.\n", chip);
+ return 1;
+ }
+ return 0;
+}
+
+static int i2c_addr_ok(const uint addr, const int alen)
+{
+ /* We support 7 or 10 bit addresses, so one or two bytes each */
+ return alen == 1 || alen == 2;
+}
+
+/* Read bytes */
+int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
+{
+ uint offset;
+ int i;
+
+ debug("i2c_read: chip=0x%x, addr=0x%x, len=0x%x\n",
+ chip, addr, len);
+ if (!i2c_addr_ok(addr, alen)) {
+ debug("i2c_read: Bad address %x.%d.\n", addr, alen);
+ return 1;
+ }
+ for (offset = 0; offset < len; offset++) {
+ if (alen) {
+ uchar data[alen];
+ for (i = 0; i < alen; i++) {
+ data[alen - i - 1] =
+ (addr + offset) >> (8 * i);
+ }
+ if (i2c_write_data(chip, data, alen)) {
+ debug("i2c_read: error sending (0x%x)\n",
+ addr);
+ return 1;
+ }
+ }
+ if (i2c_read_data(chip, buffer + offset, 1)) {
+ debug("i2c_read: error reading (0x%x)\n", addr);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/* Write bytes */
+int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
+{
+ uint offset;
+ int i;
+
+ debug("i2c_write: chip=0x%x, addr=0x%x, len=0x%x\n",
+ chip, addr, len);
+ if (!i2c_addr_ok(addr, alen)) {
+ debug("i2c_write: Bad address %x.%d.\n", addr, alen);
+ return 1;
+ }
+ for (offset = 0; offset < len; offset++) {
+ uchar data[alen + 1];
+ for (i = 0; i < alen; i++)
+ data[alen - i - 1] = (addr + offset) >> (8 * i);
+ data[alen] = buffer[offset];
+ if (i2c_write_data(chip, data, alen + 1)) {
+ debug("i2c_write: error sending (0x%x)\n", addr);
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+#if defined(CONFIG_I2C_MULTI_BUS)
+/*
+ * Functions for multiple I2C bus handling
+ */
+unsigned int i2c_get_bus_num(void)
+{
+ return i2c_bus_num;
+}
+
+int i2c_set_bus_num(unsigned int bus)
+{
+ if (bus >= TEGRA_I2C_NUM_CONTROLLERS || !i2c_controllers[bus].inited)
+ return -1;
+ i2c_bus_num = bus;
+
+ return 0;
+}
+#endif