scsi: hisi_sas: directly attached disk LED feature for v2 hw

This patch implements LED feature of directly attached disk for v2 hw.
As libsas has provided an interface lldd_write_gpio() for this feature,
we just need realise the interface following SPGIO API.

We use an CPLD to finish the hardware part of this feature, and the base
address of CPLD should be configured through ACPI or DT tables.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hisi_sas/hisi_sas.h

@@ -244,6 +244,8 @@ struct hisi_sas_hw {
 				struct domain_device *device);
 	int (*soft_reset)(struct hisi_hba *hisi_hba);
 	u32 (*get_phys_state)(struct hisi_hba *hisi_hba);
+	int (*write_gpio)(struct hisi_hba *hisi_hba, u8 reg_type,
+				u8 reg_index, u8 reg_count, u8 *write_data);
 	int max_command_entries;
 	int complete_hdr_size;
 };
@@ -257,6 +259,7 @@ struct hisi_hba {
 	struct device *dev;
 
 	void __iomem *regs;
+	void __iomem *sgpio_regs;
 	struct regmap *ctrl;
 	u32 ctrl_reset_reg;
 	u32 ctrl_reset_sts_reg;

drivers/scsi/hisi_sas/hisi_sas_main.c

@@ -1634,6 +1634,18 @@ static void hisi_sas_port_deformed(struct asd_sas_phy *sas_phy)
 {
 }
 
+static int hisi_sas_write_gpio(struct sas_ha_struct *sha, u8 reg_type,
+			u8 reg_index, u8 reg_count, u8 *write_data)
+{
+	struct hisi_hba *hisi_hba = sha->lldd_ha;
+
+	if (!hisi_hba->hw->write_gpio)
+		return -EOPNOTSUPP;
+
+	return hisi_hba->hw->write_gpio(hisi_hba, reg_type,
+				reg_index, reg_count, write_data);
+}
+
 static void hisi_sas_phy_disconnected(struct hisi_sas_phy *phy)
 {
 	phy->phy_attached = 0;
@@ -1731,6 +1743,7 @@ static struct sas_domain_function_template hisi_sas_transport_ops = {
 	.lldd_clear_nexus_ha = hisi_sas_clear_nexus_ha,
 	.lldd_port_formed	= hisi_sas_port_formed,
 	.lldd_port_deformed = hisi_sas_port_deformed,
+	.lldd_write_gpio = hisi_sas_write_gpio,
 };
 
 void hisi_sas_init_mem(struct hisi_hba *hisi_hba)
@@ -2055,6 +2068,13 @@ static struct Scsi_Host *hisi_sas_shost_alloc(struct platform_device *pdev,
 	if (IS_ERR(hisi_hba->regs))
 		goto err_out;
 
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (res) {
+		hisi_hba->sgpio_regs = devm_ioremap_resource(dev, res);
+		if (IS_ERR(hisi_hba->sgpio_regs))
+			goto err_out;
+	}
+
 	if (hisi_sas_alloc(hisi_hba, shost)) {
 		hisi_sas_free(hisi_hba);
 		goto err_out;

drivers/scsi/hisi_sas/hisi_sas_v2_hw.c

@@ -3474,6 +3474,44 @@ static int soft_reset_v2_hw(struct hisi_hba *hisi_hba)
 	return 0;
 }
 
+static int write_gpio_v2_hw(struct hisi_hba *hisi_hba, u8 reg_type,
+			u8 reg_index, u8 reg_count, u8 *write_data)
+{
+	struct device *dev = hisi_hba->dev;
+	int phy_no, count;
+
+	if (!hisi_hba->sgpio_regs)
+		return -EOPNOTSUPP;
+
+	switch (reg_type) {
+	case SAS_GPIO_REG_TX:
+		count = reg_count * 4;
+		count = min(count, hisi_hba->n_phy);
+
+		for (phy_no = 0; phy_no < count; phy_no++) {
+			/*
+			 * GPIO_TX[n] register has the highest numbered drive
+			 * of the four in the first byte and the lowest
+			 * numbered drive in the fourth byte.
+			 * See SFF-8485 Rev. 0.7 Table 24.
+			 */
+			void __iomem  *reg_addr = hisi_hba->sgpio_regs +
+					reg_index * 4 + phy_no;
+			int data_idx = phy_no + 3 - (phy_no % 4) * 2;
+
+			writeb(write_data[data_idx], reg_addr);
+		}
+
+		break;
+	default:
+		dev_err(dev, "write gpio: unsupported or bad reg type %d\n",
+				reg_type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static const struct hisi_sas_hw hisi_sas_v2_hw = {
 	.hw_init = hisi_sas_v2_init,
 	.setup_itct = setup_itct_v2_hw,
@@ -3501,6 +3539,7 @@ static const struct hisi_sas_hw hisi_sas_v2_hw = {
 	.complete_hdr_size = sizeof(struct hisi_sas_complete_v2_hdr),
 	.soft_reset = soft_reset_v2_hw,
 	.get_phys_state = get_phys_state_v2_hw,
+	.write_gpio = write_gpio_v2_hw,
 };
 
 static int hisi_sas_v2_probe(struct platform_device *pdev)