scsi: hisi_sas: Add v2 hw support for different refclk

The hip06 D03 and hip07 D05 boards have different reference clock
frequencies for the SAS controller.

Register PHY_CTRL needs to be programmed differently according to this
frequency, so add support for this.

The default register setting in PHY_CTRL is for 50MHz, so only update
this register when the refclk frequency is 66MHz.

For ACPI we expect the _RST handler to set the correct value for
PHY_CTRL (we're forced to take different approach for DT and ACPI as
ACPI does not support fixed-clock device).
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hisi_sas/hisi_sas.h

@@ -13,6 +13,7 @@
 #define _HISI_SAS_H_
 
 #include <linux/acpi.h>
+#include <linux/clk.h>
 #include <linux/dmapool.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
@@ -183,6 +184,7 @@ struct hisi_hba {
 	u32 ctrl_reset_reg;
 	u32 ctrl_reset_sts_reg;
 	u32 ctrl_clock_ena_reg;
+	u32 refclk_frequency_mhz;
 	u8 sas_addr[SAS_ADDR_SIZE];
 
 	int n_phy;

drivers/scsi/hisi_sas/hisi_sas_main.c

@@ -1396,6 +1396,7 @@ static struct Scsi_Host *hisi_sas_shost_alloc(struct platform_device *pdev,
 	struct hisi_hba *hisi_hba;
 	struct device *dev = &pdev->dev;
 	struct device_node *np = pdev->dev.of_node;
+	struct clk *refclk;
 
 	shost = scsi_host_alloc(&hisi_sas_sht, sizeof(*hisi_hba));
 	if (!shost)
@@ -1432,6 +1433,12 @@ static struct Scsi_Host *hisi_sas_shost_alloc(struct platform_device *pdev,
 			goto err_out;
 	}
 
+	refclk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(refclk))
+		dev_info(dev, "no ref clk property\n");
+	else
+		hisi_hba->refclk_frequency_mhz = clk_get_rate(refclk) / 1000000;
+
 	if (device_property_read_u32(dev, "phy-count", &hisi_hba->n_phy))
 		goto err_out;
 

drivers/scsi/hisi_sas/hisi_sas_v2_hw.c

@@ -836,7 +836,9 @@ static void init_reg_v2_hw(struct hisi_hba *hisi_hba)
 		hisi_sas_phy_write32(hisi_hba, i, SL_RX_BCAST_CHK_MSK, 0x0);
 		hisi_sas_phy_write32(hisi_hba, i, CHL_INT_COAL_EN, 0x0);
 		hisi_sas_phy_write32(hisi_hba, i, PHYCTRL_OOB_RESTART_MSK, 0x0);
-		hisi_sas_phy_write32(hisi_hba, i, PHY_CTRL, 0x199B694);
+		if (hisi_hba->refclk_frequency_mhz == 66)
+			hisi_sas_phy_write32(hisi_hba, i, PHY_CTRL, 0x199B694);
+		/* else, do nothing -> leave it how you found it */
 	}
 
 	for (i = 0; i < hisi_hba->queue_count; i++) {