Re: [PATCH v7 3/7] drivers/i2c: Add port structure to FSI algorithm

From: Eddie James
Date: Wed May 30 2018 - 11:50:03 EST




On 05/29/2018 06:19 PM, Andy Shevchenko wrote:
On Wed, May 30, 2018 at 1:24 AM, Eddie James <eajames@xxxxxxxxxxxxxxxxxx> wrote:
From: "Edward A. James" <eajames@xxxxxxxxxx>

Add and initialize I2C adapters for each port on the FSI-attached I2C
master. Ports for each master are defined in the devicetree.
+#include <linux/of.h>

+static int fsi_i2c_set_port(struct fsi_i2c_port *port)
+{
+ int rc;
+ struct fsi_device *fsi = port->master->fsi;
+ u32 mode, dummy = 0;
+ u16 old_port;
+
+ rc = fsi_i2c_read_reg(fsi, I2C_FSI_MODE, &mode);
+ if (rc)
+ return rc;
+
+ old_port = GETFIELD(I2C_MODE_PORT, mode);
+
+ if (old_port != port->port) {
Why not simple

if (port->port == GETFIELD())
return 0;

?

+ /* reset engine when port is changed */
+ rc = fsi_i2c_write_reg(fsi, I2C_FSI_RESET_ERR, &dummy);
+ if (rc)
+ return rc;
+ }
+ return rc;
It's hardly would be non-zero, right?

Sorry, misunderstood your comment here. You are correct, it can only be zero.

Thanks,
Eddie


+}
static int fsi_i2c_probe(struct device *dev)
{
Isn't below somehow repeats of_i2c_register_devices() ?
Why not to use it?

+ /* 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 = devm_kzalloc(dev, 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);
+ devm_kfree(dev, port);
This hurts my eyes. Why?!

+ continue;
+ }
+
+ list_add(&port->list, &i2c->ports);
+ }
+
dev_set_drvdata(dev, i2c);

return 0;
}
+ if (!list_empty(&i2c->ports)) {
My gosh, this is done already in list_for_each*()

+ list_for_each_entry(port, &i2c->ports, list) {
+ i2c_del_adapter(&port->adapter);
+ }
+ }