On 06/04/2018 02:17 PM, Andy Shevchenko wrote:
On Mon, Jun 4, 2018 at 10:00 PM, Eddie James <eajames@xxxxxxxxxxxxxxxxxx> wrote:Add and initialize I2C adapters for each port on the FSI-attached I2C master. Ports for each master are defined in the devicetree. Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxxxxxxx> --- drivers/i2c/busses/i2c-fsi.c | 90 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c index e1b183c..12130c3 100644 --- a/drivers/i2c/busses/i2c-fsi.c +++ b/drivers/i2c/busses/i2c-fsi.c @@ -17,7 +17,10 @@ #include <linux/fsi.h> #include <linux/i2c.h> #include <linux/kernel.h> +#include <linux/list.h> #include <linux/module.h> +#include <linux/of.h> +#include <linux/slab.h> #define FSI_ENGID_I2C 0x7 @@ -123,6 +126,14 @@ struct fsi_i2c_master { struct fsi_device *fsi; u8 fifo_size; + struct list_head ports; +}; + +struct fsi_i2c_port { + struct list_head list; + struct i2c_adapter adapter; + struct fsi_i2c_master *master; + u16 port; }; static int fsi_i2c_read_reg(struct fsi_device *fsi, unsigned int reg, @@ -176,9 +187,38 @@ static int fsi_i2c_dev_init(struct fsi_i2c_master *i2c) 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);Did you consider to split this to two lines / assignments?
It fit on one line (< 80 chars) so I left it as-is...
+ 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_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { + int rc; + struct fsi_i2c_port *port = adap->algo_data; + + rc = fsi_i2c_set_port(port); + if (rc) + return rc; + return -EOPNOTSUPP; } @@ -196,23 +236,72 @@ static u32 fsi_i2c_functionality(struct i2c_adapter *adap) static int fsi_i2c_probe(struct device *dev) { struct fsi_i2c_master *i2c; + struct fsi_i2c_port *port; + struct device_node *np; int rc; + u32 port_no; i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL); if (!i2c) return -ENOMEM; i2c->fsi = to_fsi_dev(dev); + INIT_LIST_HEAD(&i2c->ports); rc = fsi_i2c_dev_init(i2c); if (rc) return rc; + /* Add adapter for each i2c port of the master. */ + for_each_available_child_of_node(dev->of_node, np) { + rc = of_property_read_u32(np, "reg", &port_no); + if (rc || port_no > USHRT_MAX) + continue;+ + port = kzalloc(sizeof(*port), GFP_KERNEL); + if (!port) + 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.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; + + list_for_each_entry(port, &i2c->ports, list) { + i2c_del_adapter(&port->adapter); + kfree(port); + }Just to be sure, it will be called if and only if all adapters are not busy. Correct?
If I understand the code and comments correctly, i2c_del_adapter will block until all references to the adapter device are gone. So, should be safe to free it now.
Thanks, Eddie
+ + return 0; +} + static const struct fsi_device_id fsi_i2c_ids[] = { { FSI_ENGID_I2C, FSI_VERSION_ANY }, { 0 } @@ -224,6 +313,7 @@ static int fsi_i2c_probe(struct device *dev) .name = "i2c-fsi", .bus = &fsi_bus_type, .probe = fsi_i2c_probe, + .remove = fsi_i2c_remove, }, }; -- 1.8.3.1
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