fsi: master-gpio: Add support for link_config

To configure the send and echo delays
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>

drivers/fsi/fsi-master-gpio.c

@@ -64,6 +64,8 @@ struct fsi_master_gpio {
 	bool			external_mode;
 	bool			no_delays;
 	uint32_t		last_addr;
+	uint8_t			t_send_delay;
+	uint8_t			t_echo_delay;
 };
 
 #define CREATE_TRACE_POINTS
@@ -338,7 +340,7 @@ static void build_epoll_command(struct fsi_gpio_msg *cmd, uint8_t slave_id)
 static void echo_delay(struct fsi_master_gpio *master)
 {
 	set_sda_output(master, 1);
-	clock_toggle(master, FSI_ECHO_DELAY_CLOCKS);
+	clock_toggle(master, master->t_echo_delay);
 }
 
 static void build_term_command(struct fsi_gpio_msg *cmd, uint8_t slave_id)
@@ -540,7 +542,7 @@ static int poll_for_response(struct fsi_master_gpio *master,
 	 * from receive of response back to send of data.
 	 */
 	local_irq_save(flags);
-	clock_zeros(master, FSI_SEND_DELAY_CLOCKS);
+	clock_zeros(master, master->t_send_delay);
 	local_irq_restore(flags);
 
 	return rc;
@@ -722,6 +724,22 @@ static int fsi_master_gpio_link_enable(struct fsi_master *_master, int link)
 	return rc;
 }
 
+static int fsi_master_gpio_link_config(struct fsi_master *_master, int link,
+				       u8 t_send_delay, u8 t_echo_delay)
+{
+	struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
+
+	if (link != 0)
+		return -ENODEV;
+
+	mutex_lock(&master->cmd_lock);
+	master->t_send_delay = t_send_delay;
+	master->t_echo_delay = t_echo_delay;
+	mutex_unlock(&master->cmd_lock);
+
+	return 0;
+}
+
 static ssize_t external_mode_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
@@ -826,6 +844,10 @@ static int fsi_master_gpio_probe(struct platform_device *pdev)
 	 */
 	master->no_delays = device_property_present(&pdev->dev, "no-gpio-delays");
 
+	/* Default FSI command delays */
+	master->t_send_delay = FSI_SEND_DELAY_CLOCKS;
+	master->t_echo_delay = FSI_ECHO_DELAY_CLOCKS;
+
 	master->master.n_links = 1;
 	master->master.flags = FSI_MASTER_FLAG_SWCLOCK;
 	master->master.read = fsi_master_gpio_read;
@@ -833,6 +855,7 @@ static int fsi_master_gpio_probe(struct platform_device *pdev)
 	master->master.term = fsi_master_gpio_term;
 	master->master.send_break = fsi_master_gpio_break;
 	master->master.link_enable = fsi_master_gpio_link_enable;
+	master->master.link_config = fsi_master_gpio_link_config;
 	platform_set_drvdata(pdev, master);
 	mutex_init(&master->cmd_lock);