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-rw-r--r--drivers/i2c/busses/i2c-fsi.c776
1 files changed, 776 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c
new file mode 100644
index 000000000..10332693e
--- /dev/null
+++ b/drivers/i2c/busses/i2c-fsi.c
@@ -0,0 +1,776 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * FSI-attached I2C master algorithm
+ *
+ * Copyright 2018 IBM Corporation
+ *
+ * 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.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/fsi.h>
+#include <linux/i2c.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#define FSI_ENGID_I2C 0x7
+
+#define I2C_DEFAULT_CLK_DIV 6
+
+/* i2c registers */
+#define I2C_FSI_FIFO 0x00
+#define I2C_FSI_CMD 0x04
+#define I2C_FSI_MODE 0x08
+#define I2C_FSI_WATER_MARK 0x0C
+#define I2C_FSI_INT_MASK 0x10
+#define I2C_FSI_INT_COND 0x14
+#define I2C_FSI_OR_INT_MASK 0x14
+#define I2C_FSI_INTS 0x18
+#define I2C_FSI_AND_INT_MASK 0x18
+#define I2C_FSI_STAT 0x1C
+#define I2C_FSI_RESET_I2C 0x1C
+#define I2C_FSI_ESTAT 0x20
+#define I2C_FSI_RESET_ERR 0x20
+#define I2C_FSI_RESID_LEN 0x24
+#define I2C_FSI_SET_SCL 0x24
+#define I2C_FSI_PORT_BUSY 0x28
+#define I2C_FSI_RESET_SCL 0x2C
+#define I2C_FSI_SET_SDA 0x30
+#define I2C_FSI_RESET_SDA 0x34
+
+/* cmd register */
+#define I2C_CMD_WITH_START BIT(31)
+#define I2C_CMD_WITH_ADDR BIT(30)
+#define I2C_CMD_RD_CONT BIT(29)
+#define I2C_CMD_WITH_STOP BIT(28)
+#define I2C_CMD_FORCELAUNCH BIT(27)
+#define I2C_CMD_ADDR GENMASK(23, 17)
+#define I2C_CMD_READ BIT(16)
+#define I2C_CMD_LEN GENMASK(15, 0)
+
+/* mode register */
+#define I2C_MODE_CLKDIV GENMASK(31, 16)
+#define I2C_MODE_PORT GENMASK(15, 10)
+#define I2C_MODE_ENHANCED BIT(3)
+#define I2C_MODE_DIAG BIT(2)
+#define I2C_MODE_PACE_ALLOW BIT(1)
+#define I2C_MODE_WRAP BIT(0)
+
+/* watermark register */
+#define I2C_WATERMARK_HI GENMASK(15, 12)
+#define I2C_WATERMARK_LO GENMASK(7, 4)
+
+#define I2C_FIFO_HI_LVL 4
+#define I2C_FIFO_LO_LVL 4
+
+/* interrupt register */
+#define I2C_INT_INV_CMD BIT(15)
+#define I2C_INT_PARITY BIT(14)
+#define I2C_INT_BE_OVERRUN BIT(13)
+#define I2C_INT_BE_ACCESS BIT(12)
+#define I2C_INT_LOST_ARB BIT(11)
+#define I2C_INT_NACK BIT(10)
+#define I2C_INT_DAT_REQ BIT(9)
+#define I2C_INT_CMD_COMP BIT(8)
+#define I2C_INT_STOP_ERR BIT(7)
+#define I2C_INT_BUSY BIT(6)
+#define I2C_INT_IDLE BIT(5)
+
+/* status register */
+#define I2C_STAT_INV_CMD BIT(31)
+#define I2C_STAT_PARITY BIT(30)
+#define I2C_STAT_BE_OVERRUN BIT(29)
+#define I2C_STAT_BE_ACCESS BIT(28)
+#define I2C_STAT_LOST_ARB BIT(27)
+#define I2C_STAT_NACK BIT(26)
+#define I2C_STAT_DAT_REQ BIT(25)
+#define I2C_STAT_CMD_COMP BIT(24)
+#define I2C_STAT_STOP_ERR BIT(23)
+#define I2C_STAT_MAX_PORT GENMASK(22, 16)
+#define I2C_STAT_ANY_INT BIT(15)
+#define I2C_STAT_SCL_IN BIT(11)
+#define I2C_STAT_SDA_IN BIT(10)
+#define I2C_STAT_PORT_BUSY BIT(9)
+#define I2C_STAT_SELF_BUSY BIT(8)
+#define I2C_STAT_FIFO_COUNT GENMASK(7, 0)
+
+#define I2C_STAT_ERR (I2C_STAT_INV_CMD | \
+ I2C_STAT_PARITY | \
+ I2C_STAT_BE_OVERRUN | \
+ I2C_STAT_BE_ACCESS | \
+ I2C_STAT_LOST_ARB | \
+ I2C_STAT_NACK | \
+ I2C_STAT_STOP_ERR)
+#define I2C_STAT_ANY_RESP (I2C_STAT_ERR | \
+ I2C_STAT_DAT_REQ | \
+ I2C_STAT_CMD_COMP)
+
+/* extended status register */
+#define I2C_ESTAT_FIFO_SZ GENMASK(31, 24)
+#define I2C_ESTAT_SCL_IN_SY BIT(15)
+#define I2C_ESTAT_SDA_IN_SY BIT(14)
+#define I2C_ESTAT_S_SCL BIT(13)
+#define I2C_ESTAT_S_SDA BIT(12)
+#define I2C_ESTAT_M_SCL BIT(11)
+#define I2C_ESTAT_M_SDA BIT(10)
+#define I2C_ESTAT_HI_WATER BIT(9)
+#define I2C_ESTAT_LO_WATER BIT(8)
+#define I2C_ESTAT_PORT_BUSY BIT(7)
+#define I2C_ESTAT_SELF_BUSY BIT(6)
+#define I2C_ESTAT_VERSION GENMASK(4, 0)
+
+/* port busy register */
+#define I2C_PORT_BUSY_RESET BIT(31)
+
+/* wait for command complete or data request */
+#define I2C_CMD_SLEEP_MAX_US 500
+#define I2C_CMD_SLEEP_MIN_US 50
+
+/* wait after reset; choose time from legacy driver */
+#define I2C_RESET_SLEEP_MAX_US 2000
+#define I2C_RESET_SLEEP_MIN_US 1000
+
+/* choose timeout length from legacy driver; it's well tested */
+#define I2C_ABORT_TIMEOUT msecs_to_jiffies(100)
+
+struct fsi_i2c_master {
+ struct fsi_device *fsi;
+ u8 fifo_size;
+ struct list_head ports;
+ struct mutex lock;
+};
+
+struct fsi_i2c_port {
+ struct list_head list;
+ struct i2c_adapter adapter;
+ struct fsi_i2c_master *master;
+ u16 port;
+ u16 xfrd;
+};
+
+static int fsi_i2c_read_reg(struct fsi_device *fsi, unsigned int reg,
+ u32 *data)
+{
+ int rc;
+ __be32 data_be;
+
+ rc = fsi_device_read(fsi, reg, &data_be, sizeof(data_be));
+ if (rc)
+ return rc;
+
+ *data = be32_to_cpu(data_be);
+
+ return 0;
+}
+
+static int fsi_i2c_write_reg(struct fsi_device *fsi, unsigned int reg,
+ u32 *data)
+{
+ __be32 data_be = cpu_to_be32p(data);
+
+ return fsi_device_write(fsi, reg, &data_be, sizeof(data_be));
+}
+
+static int fsi_i2c_dev_init(struct fsi_i2c_master *i2c)
+{
+ int rc;
+ u32 mode = I2C_MODE_ENHANCED, extended_status, watermark;
+ u32 interrupt = 0;
+
+ /* since we use polling, disable interrupts */
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_INT_MASK, &interrupt);
+ if (rc)
+ return rc;
+
+ mode |= FIELD_PREP(I2C_MODE_CLKDIV, I2C_DEFAULT_CLK_DIV);
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return rc;
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_ESTAT, &extended_status);
+ if (rc)
+ return rc;
+
+ i2c->fifo_size = FIELD_GET(I2C_ESTAT_FIFO_SZ, extended_status);
+ watermark = FIELD_PREP(I2C_WATERMARK_HI,
+ i2c->fifo_size - I2C_FIFO_HI_LVL);
+ watermark |= FIELD_PREP(I2C_WATERMARK_LO, I2C_FIFO_LO_LVL);
+
+ return fsi_i2c_write_reg(i2c->fsi, I2C_FSI_WATER_MARK, &watermark);
+}
+
+static int fsi_i2c_set_port(struct fsi_i2c_port *port)
+{
+ int rc;
+ struct fsi_device *fsi = port->master->fsi;
+ u32 mode, dummy = 0;
+
+ rc = fsi_i2c_read_reg(fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return rc;
+
+ if (FIELD_GET(I2C_MODE_PORT, mode) == port->port)
+ return 0;
+
+ mode = (mode & ~I2C_MODE_PORT) | FIELD_PREP(I2C_MODE_PORT, port->port);
+ rc = fsi_i2c_write_reg(fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return rc;
+
+ /* reset engine when port is changed */
+ return fsi_i2c_write_reg(fsi, I2C_FSI_RESET_ERR, &dummy);
+}
+
+static int fsi_i2c_start(struct fsi_i2c_port *port, struct i2c_msg *msg,
+ bool stop)
+{
+ struct fsi_i2c_master *i2c = port->master;
+ u32 cmd = I2C_CMD_WITH_START | I2C_CMD_WITH_ADDR;
+
+ port->xfrd = 0;
+
+ if (msg->flags & I2C_M_RD)
+ cmd |= I2C_CMD_READ;
+
+ if (stop || msg->flags & I2C_M_STOP)
+ cmd |= I2C_CMD_WITH_STOP;
+
+ cmd |= FIELD_PREP(I2C_CMD_ADDR, msg->addr);
+ cmd |= FIELD_PREP(I2C_CMD_LEN, msg->len);
+
+ return fsi_i2c_write_reg(i2c->fsi, I2C_FSI_CMD, &cmd);
+}
+
+static int fsi_i2c_get_op_bytes(int op_bytes)
+{
+ /* fsi is limited to max 4 byte aligned ops */
+ if (op_bytes > 4)
+ return 4;
+ else if (op_bytes == 3)
+ return 2;
+ return op_bytes;
+}
+
+static int fsi_i2c_write_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg,
+ u8 fifo_count)
+{
+ int write;
+ int rc;
+ struct fsi_i2c_master *i2c = port->master;
+ int bytes_to_write = i2c->fifo_size - fifo_count;
+ int bytes_remaining = msg->len - port->xfrd;
+
+ bytes_to_write = min(bytes_to_write, bytes_remaining);
+
+ while (bytes_to_write) {
+ write = fsi_i2c_get_op_bytes(bytes_to_write);
+
+ rc = fsi_device_write(i2c->fsi, I2C_FSI_FIFO,
+ &msg->buf[port->xfrd], write);
+ if (rc)
+ return rc;
+
+ port->xfrd += write;
+ bytes_to_write -= write;
+ }
+
+ return 0;
+}
+
+static int fsi_i2c_read_fifo(struct fsi_i2c_port *port, struct i2c_msg *msg,
+ u8 fifo_count)
+{
+ int read;
+ int rc;
+ struct fsi_i2c_master *i2c = port->master;
+ int bytes_to_read;
+ int xfr_remaining = msg->len - port->xfrd;
+ u32 dummy;
+
+ bytes_to_read = min_t(int, fifo_count, xfr_remaining);
+
+ while (bytes_to_read) {
+ read = fsi_i2c_get_op_bytes(bytes_to_read);
+
+ if (xfr_remaining) {
+ rc = fsi_device_read(i2c->fsi, I2C_FSI_FIFO,
+ &msg->buf[port->xfrd], read);
+ if (rc)
+ return rc;
+
+ port->xfrd += read;
+ xfr_remaining -= read;
+ } else {
+ /* no more buffer but data in fifo, need to clear it */
+ rc = fsi_device_read(i2c->fsi, I2C_FSI_FIFO, &dummy,
+ read);
+ if (rc)
+ return rc;
+ }
+
+ bytes_to_read -= read;
+ }
+
+ return 0;
+}
+
+static int fsi_i2c_get_scl(struct i2c_adapter *adap)
+{
+ u32 stat = 0;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+
+ return !!(stat & I2C_STAT_SCL_IN);
+}
+
+static void fsi_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+ u32 dummy = 0;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ if (val)
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SCL, &dummy);
+ else
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SCL, &dummy);
+}
+
+static int fsi_i2c_get_sda(struct i2c_adapter *adap)
+{
+ u32 stat = 0;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+
+ return !!(stat & I2C_STAT_SDA_IN);
+}
+
+static void fsi_i2c_set_sda(struct i2c_adapter *adap, int val)
+{
+ u32 dummy = 0;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ if (val)
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_SET_SDA, &dummy);
+ else
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_SDA, &dummy);
+}
+
+static void fsi_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+ int rc;
+ u32 mode;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return;
+
+ mode |= I2C_MODE_DIAG;
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+}
+
+static void fsi_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+ int rc;
+ u32 mode;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *i2c = port->master;
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return;
+
+ mode &= ~I2C_MODE_DIAG;
+ fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+}
+
+static int fsi_i2c_reset_bus(struct fsi_i2c_master *i2c,
+ struct fsi_i2c_port *port)
+{
+ int rc;
+ u32 stat, dummy = 0;
+
+ /* force bus reset, ignore errors */
+ i2c_recover_bus(&port->adapter);
+
+ /* reset errors */
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_ERR, &dummy);
+ if (rc)
+ return rc;
+
+ /* wait for command complete */
+ usleep_range(I2C_RESET_SLEEP_MIN_US, I2C_RESET_SLEEP_MAX_US);
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+ if (rc)
+ return rc;
+
+ if (stat & I2C_STAT_CMD_COMP)
+ return 0;
+
+ /* failed to get command complete; reset engine again */
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy);
+ if (rc)
+ return rc;
+
+ /* re-init engine again */
+ return fsi_i2c_dev_init(i2c);
+}
+
+static int fsi_i2c_reset_engine(struct fsi_i2c_master *i2c, u16 port)
+{
+ int rc;
+ u32 mode, dummy = 0;
+
+ /* reset engine */
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_RESET_I2C, &dummy);
+ if (rc)
+ return rc;
+
+ /* re-init engine */
+ rc = fsi_i2c_dev_init(i2c);
+ if (rc)
+ return rc;
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return rc;
+
+ /* set port; default after reset is 0 */
+ if (port) {
+ mode &= ~I2C_MODE_PORT;
+ mode |= FIELD_PREP(I2C_MODE_PORT, port);
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return rc;
+ }
+
+ /* reset busy register; hw workaround */
+ dummy = I2C_PORT_BUSY_RESET;
+ rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_PORT_BUSY, &dummy);
+ if (rc)
+ return rc;
+
+ return 0;
+}
+
+static int fsi_i2c_abort(struct fsi_i2c_port *port, u32 status)
+{
+ int rc;
+ unsigned long start;
+ u32 cmd = I2C_CMD_WITH_STOP;
+ u32 stat;
+ struct fsi_i2c_master *i2c = port->master;
+ struct fsi_device *fsi = i2c->fsi;
+
+ rc = fsi_i2c_reset_engine(i2c, port->port);
+ if (rc)
+ return rc;
+
+ rc = fsi_i2c_read_reg(fsi, I2C_FSI_STAT, &stat);
+ if (rc)
+ return rc;
+
+ /* if sda is low, peform full bus reset */
+ if (!(stat & I2C_STAT_SDA_IN)) {
+ rc = fsi_i2c_reset_bus(i2c, port);
+ if (rc)
+ return rc;
+ }
+
+ /* skip final stop command for these errors */
+ if (status & (I2C_STAT_PARITY | I2C_STAT_LOST_ARB | I2C_STAT_STOP_ERR))
+ return 0;
+
+ /* write stop command */
+ rc = fsi_i2c_write_reg(fsi, I2C_FSI_CMD, &cmd);
+ if (rc)
+ return rc;
+
+ /* wait until we see command complete in the master */
+ start = jiffies;
+
+ do {
+ rc = fsi_i2c_read_reg(fsi, I2C_FSI_STAT, &status);
+ if (rc)
+ return rc;
+
+ if (status & I2C_STAT_CMD_COMP)
+ return 0;
+
+ usleep_range(I2C_CMD_SLEEP_MIN_US, I2C_CMD_SLEEP_MAX_US);
+ } while (time_after(start + I2C_ABORT_TIMEOUT, jiffies));
+
+ return -ETIMEDOUT;
+}
+
+static int fsi_i2c_handle_status(struct fsi_i2c_port *port,
+ struct i2c_msg *msg, u32 status)
+{
+ int rc;
+ u8 fifo_count;
+
+ if (status & I2C_STAT_ERR) {
+ rc = fsi_i2c_abort(port, status);
+ if (rc)
+ return rc;
+
+ if (status & I2C_STAT_INV_CMD)
+ return -EINVAL;
+
+ if (status & (I2C_STAT_PARITY | I2C_STAT_BE_OVERRUN |
+ I2C_STAT_BE_ACCESS))
+ return -EPROTO;
+
+ if (status & I2C_STAT_NACK)
+ return -ENXIO;
+
+ if (status & I2C_STAT_LOST_ARB)
+ return -EAGAIN;
+
+ if (status & I2C_STAT_STOP_ERR)
+ return -EBADMSG;
+
+ return -EIO;
+ }
+
+ if (status & I2C_STAT_DAT_REQ) {
+ fifo_count = FIELD_GET(I2C_STAT_FIFO_COUNT, status);
+
+ if (msg->flags & I2C_M_RD)
+ return fsi_i2c_read_fifo(port, msg, fifo_count);
+
+ return fsi_i2c_write_fifo(port, msg, fifo_count);
+ }
+
+ if (status & I2C_STAT_CMD_COMP) {
+ if (port->xfrd < msg->len)
+ return -ENODATA;
+
+ return msg->len;
+ }
+
+ return 0;
+}
+
+static int fsi_i2c_wait(struct fsi_i2c_port *port, struct i2c_msg *msg,
+ unsigned long timeout)
+{
+ u32 status = 0;
+ int rc;
+ unsigned long start = jiffies;
+
+ do {
+ rc = fsi_i2c_read_reg(port->master->fsi, I2C_FSI_STAT,
+ &status);
+ if (rc)
+ return rc;
+
+ if (status & I2C_STAT_ANY_RESP) {
+ rc = fsi_i2c_handle_status(port, msg, status);
+ if (rc < 0)
+ return rc;
+
+ /* cmd complete and all data xfrd */
+ if (rc == msg->len)
+ return 0;
+
+ /* need to xfr more data, but maybe don't need wait */
+ continue;
+ }
+
+ usleep_range(I2C_CMD_SLEEP_MIN_US, I2C_CMD_SLEEP_MAX_US);
+ } while (time_after(start + timeout, jiffies));
+
+ return -ETIMEDOUT;
+}
+
+static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ int i, rc;
+ unsigned long start_time;
+ struct fsi_i2c_port *port = adap->algo_data;
+ struct fsi_i2c_master *master = port->master;
+ struct i2c_msg *msg;
+
+ mutex_lock(&master->lock);
+
+ rc = fsi_i2c_set_port(port);
+ if (rc)
+ goto unlock;
+
+ for (i = 0; i < num; i++) {
+ msg = msgs + i;
+ start_time = jiffies;
+
+ rc = fsi_i2c_start(port, msg, i == num - 1);
+ if (rc)
+ goto unlock;
+
+ rc = fsi_i2c_wait(port, msg,
+ adap->timeout - (jiffies - start_time));
+ if (rc)
+ goto unlock;
+ }
+
+unlock:
+ mutex_unlock(&master->lock);
+ return rc ? : num;
+}
+
+static u32 fsi_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING |
+ I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static struct i2c_bus_recovery_info fsi_i2c_bus_recovery_info = {
+ .recover_bus = i2c_generic_scl_recovery,
+ .get_scl = fsi_i2c_get_scl,
+ .set_scl = fsi_i2c_set_scl,
+ .get_sda = fsi_i2c_get_sda,
+ .set_sda = fsi_i2c_set_sda,
+ .prepare_recovery = fsi_i2c_prepare_recovery,
+ .unprepare_recovery = fsi_i2c_unprepare_recovery,
+};
+
+static const struct i2c_algorithm fsi_i2c_algorithm = {
+ .master_xfer = fsi_i2c_xfer,
+ .functionality = fsi_i2c_functionality,
+};
+
+static struct device_node *fsi_i2c_find_port_of_node(struct device_node *fsi,
+ int port)
+{
+ struct device_node *np;
+ u32 port_no;
+ int rc;
+
+ for_each_child_of_node(fsi, np) {
+ rc = of_property_read_u32(np, "reg", &port_no);
+ if (!rc && port_no == port)
+ return np;
+ }
+
+ return NULL;
+}
+
+static int fsi_i2c_probe(struct device *dev)
+{
+ struct fsi_i2c_master *i2c;
+ struct fsi_i2c_port *port;
+ struct device_node *np;
+ u32 port_no, ports, stat;
+ int rc;
+
+ i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
+ if (!i2c)
+ return -ENOMEM;
+
+ mutex_init(&i2c->lock);
+ i2c->fsi = to_fsi_dev(dev);
+ INIT_LIST_HEAD(&i2c->ports);
+
+ rc = fsi_i2c_dev_init(i2c);
+ if (rc)
+ return rc;
+
+ rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_STAT, &stat);
+ if (rc)
+ return rc;
+
+ ports = FIELD_GET(I2C_STAT_MAX_PORT, stat) + 1;
+ dev_dbg(dev, "I2C master has %d ports\n", ports);
+
+ for (port_no = 0; port_no < ports; port_no++) {
+ np = fsi_i2c_find_port_of_node(dev->of_node, port_no);
+ if (!of_device_is_available(np))
+ continue;
+
+ port = kzalloc(sizeof(*port), GFP_KERNEL);
+ if (!port) {
+ of_node_put(np);
+ break;
+ }
+
+ port->master = i2c;
+ port->port = port_no;
+
+ port->adapter.owner = THIS_MODULE;
+ port->adapter.dev.of_node = np;
+ port->adapter.dev.parent = dev;
+ port->adapter.algo = &fsi_i2c_algorithm;
+ port->adapter.bus_recovery_info = &fsi_i2c_bus_recovery_info;
+ port->adapter.algo_data = port;
+
+ snprintf(port->adapter.name, sizeof(port->adapter.name),
+ "i2c_bus-%u", port_no);
+
+ rc = i2c_add_adapter(&port->adapter);
+ if (rc < 0) {
+ dev_err(dev, "Failed to register adapter: %d\n", rc);
+ kfree(port);
+ continue;
+ }
+
+ list_add(&port->list, &i2c->ports);
+ }
+
+ dev_set_drvdata(dev, i2c);
+
+ return 0;
+}
+
+static int fsi_i2c_remove(struct device *dev)
+{
+ struct fsi_i2c_master *i2c = dev_get_drvdata(dev);
+ struct fsi_i2c_port *port, *tmp;
+
+ list_for_each_entry_safe(port, tmp, &i2c->ports, list) {
+ list_del(&port->list);
+ i2c_del_adapter(&port->adapter);
+ kfree(port);
+ }
+
+ return 0;
+}
+
+static const struct fsi_device_id fsi_i2c_ids[] = {
+ { FSI_ENGID_I2C, FSI_VERSION_ANY },
+ { }
+};
+
+static struct fsi_driver fsi_i2c_driver = {
+ .id_table = fsi_i2c_ids,
+ .drv = {
+ .name = "i2c-fsi",
+ .bus = &fsi_bus_type,
+ .probe = fsi_i2c_probe,
+ .remove = fsi_i2c_remove,
+ },
+};
+
+module_fsi_driver(fsi_i2c_driver);
+
+MODULE_AUTHOR("Eddie James <eajames@us.ibm.com>");
+MODULE_DESCRIPTION("FSI attached I2C master");
+MODULE_LICENSE("GPL");