[PATCH v3 net-next 2/2] net: macb: Add zynqmp SGMII dynamic configuration support

[Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>]

Add support for the dynamic configuration which takes care of
configuring the GEM secure space configuration registers
using EEMI APIs.
High level sequence is to:
- Check for the PM dynamic configuration support, if no error proceed with
  GEM dynamic configurations(next steps) otherwise skip the dynamic
  configuration.
- Configure GEM Fixed configurations.
- Configure GEM_CLK_CTRL (gemX_sgmii_mode).
- Trigger GEM reset.

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Conor Dooley <conor.dooley@microchip.com> (for MPFS)
---
Changes for v3:
- Introduce goto for common phy_exit return path.
- Change return check to if(ret) for of_property_read_u32_array
  and zynqmp_pm_set_gem_config APIs.

Changes for v2:
- Add phy_exit() in error return paths.
---
 drivers/net/ethernet/cadence/macb_main.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 66c7d08d376a..4769c8a0c73a 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c
@@ -38,6 +38,7 @@
 #include <linux/pm_runtime.h>
 #include <linux/ptp_classify.h>
 #include <linux/reset.h>
+#include <linux/firmware/xlnx-zynqmp.h>
 #include "macb.h"
 
 /* This structure is only used for MACB on SiFive FU540 devices */
@@ -4621,6 +4622,25 @@ static int init_reset_optional(struct platform_device *pdev)
 					     "failed to init SGMII PHY\n");
 	}
 
+	ret = zynqmp_pm_is_function_supported(PM_IOCTL, IOCTL_SET_GEM_CONFIG);
+	if (!ret) {
+		u32 pm_info[2];
+
+		ret = of_property_read_u32_array(pdev->dev.of_node, "power-domains",
+						 pm_info, ARRAY_SIZE(pm_info));
+		if (ret) {
+			dev_err(&pdev->dev, "Failed to read power management information\n");
+			goto err_out_phy_exit;
+		}
+		ret = zynqmp_pm_set_gem_config(pm_info[1], GEM_CONFIG_FIXED, 0);
+		if (ret)
+			goto err_out_phy_exit;
+
+		ret = zynqmp_pm_set_gem_config(pm_info[1], GEM_CONFIG_SGMII_MODE, 1);
+		if (ret)
+			goto err_out_phy_exit;
+	}
+
 	/* Fully reset controller at hardware level if mapped in device tree */
 	ret = device_reset_optional(&pdev->dev);
 	if (ret) {
@@ -4629,6 +4649,8 @@ static int init_reset_optional(struct platform_device *pdev)
 	}
 
 	ret = macb_init(pdev);
+
+err_out_phy_exit:
 	if (ret)
 		phy_exit(bp->sgmii_phy);
 
-- 
2.25.1