irqchip/ls-scfg-msi: Add LS1046a MSI support

LS1046a includes 4 MSIRs, each MSIR is assigned a dedicate GIC
SPI interrupt and provides 32 MSI interrupts. Compared to previous
MSI, LS1046a's IBS(interrupt bit select) shift is changed to 2 and
total MSI interrupt number is changed to 128.

The patch adds structure 'ls_scfg_msir' to describe MSIR setting and
'ibs_shift' to store the different value between the SoCs.

Signed-off-by: Minghuan Lian <[e-mail]>
Signed-off-by: Hou Zhiqiang <[e-mail]>
Signed-off-by: Marc Zyngier <[e-mail]>

drivers/irqchip/irq-ls-scfg-msi.c

···
 #include <linux/irq.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
+#include <linux/of_irq.h>
 #include <linux/of_pci.h>
 #include <linux/of_platform.h>
 #include <linux/spinlock.h>
 
-#define MSI_MAX_IRQS	32
-#define MSI_IBS_SHIFT	3
-#define MSIR		4
+#define MSI_IRQS_PER_MSIR	32
+#define MSI_MSIR_OFFSET		4
+
+struct ls_scfg_msi_cfg {
+	u32 ibs_shift; /* Shift of interrupt bit select */
+};
+
+struct ls_scfg_msir {
+	struct ls_scfg_msi *msi_data;
+	unsigned int index;
+	unsigned int gic_irq;
+	void __iomem *reg;
+};
 
 struct ls_scfg_msi {
 	spinlock_t		lock;
···
 	struct irq_domain	*msi_domain;
 	void __iomem		*regs;
 	phys_addr_t		msiir_addr;
-	int			irq;
-	DECLARE_BITMAP(used, MSI_MAX_IRQS);
+	struct ls_scfg_msi_cfg	*cfg;
+	u32			msir_num;
+	struct ls_scfg_msir	*msir;
+	u32			irqs_num;
+	unsigned long		*used;
 };
 
 static struct irq_chip ls_scfg_msi_irq_chip = {
···
 
 	msg->address_hi = upper_32_bits(msi_data->msiir_addr);
 	msg->address_lo = lower_32_bits(msi_data->msiir_addr);
-	msg->data = data->hwirq << MSI_IBS_SHIFT;
+	msg->data = data->hwirq;
 }
 
 static int ls_scfg_msi_set_affinity(struct irq_data *irq_data,
···
 	WARN_ON(nr_irqs != 1);
 
 	spin_lock(&msi_data->lock);
-	pos = find_first_zero_bit(msi_data->used, MSI_MAX_IRQS);
-	if (pos < MSI_MAX_IRQS)
+	pos = find_first_zero_bit(msi_data->used, msi_data->irqs_num);
+	if (pos < msi_data->irqs_num)
 		__set_bit(pos, msi_data->used);
 	else
 		err = -ENOSPC;
···
 	int pos;
 
 	pos = d->hwirq;
-	if (pos < 0 || pos >= MSI_MAX_IRQS) {
+	if (pos < 0 || pos >= msi_data->irqs_num) {
 		pr_err("failed to teardown msi. Invalid hwirq %d\n", pos);
 		return;
 	}
···
 
 static void ls_scfg_msi_irq_handler(struct irq_desc *desc)
 {
-	struct ls_scfg_msi *msi_data = irq_desc_get_handler_data(desc);
+	struct ls_scfg_msir *msir = irq_desc_get_handler_data(desc);
+	struct ls_scfg_msi *msi_data = msir->msi_data;
 	unsigned long val;
-	int pos, virq;
+	int pos, virq, hwirq;
 
 	chained_irq_enter(irq_desc_get_chip(desc), desc);
 
-	val = ioread32be(msi_data->regs + MSIR);
-	for_each_set_bit(pos, &val, MSI_MAX_IRQS) {
-		virq = irq_find_mapping(msi_data->parent, (31 - pos));
+	val = ioread32be(msir->reg);
+	for_each_set_bit(pos, &val, MSI_IRQS_PER_MSIR) {
+		hwirq = ((31 - pos) << msi_data->cfg->ibs_shift) | msir->index;
+		virq = irq_find_mapping(msi_data->parent, hwirq);
 		if (virq)
 			generic_handle_irq(virq);
 	}
···
 {
 	/* Initialize MSI domain parent */
 	msi_data->parent = irq_domain_add_linear(NULL,
-						 MSI_MAX_IRQS,
+						 msi_data->irqs_num,
 						 &ls_scfg_msi_domain_ops,
 						 msi_data);
 	if (!msi_data->parent) {
···
 	return 0;
 }
 
+static int ls_scfg_msi_setup_hwirq(struct ls_scfg_msi *msi_data, int index)
+{
+	struct ls_scfg_msir *msir;
+	int virq, i, hwirq;
+
+	virq = platform_get_irq(msi_data->pdev, index);
+	if (virq <= 0)
+		return -ENODEV;
+
+	msir = &msi_data->msir[index];
+	msir->index = index;
+	msir->msi_data = msi_data;
+	msir->gic_irq = virq;
+	msir->reg = msi_data->regs + MSI_MSIR_OFFSET + 4 * index;
+
+	irq_set_chained_handler_and_data(msir->gic_irq,
+					 ls_scfg_msi_irq_handler,
+					 msir);
+
+	/* Release the hwirqs corresponding to this MSIR */
+	for (i = 0; i < MSI_IRQS_PER_MSIR; i++) {
+		hwirq = i << msi_data->cfg->ibs_shift | msir->index;
+		bitmap_clear(msi_data->used, hwirq, 1);
+	}
+
+	return 0;
+}
+
+static int ls_scfg_msi_teardown_hwirq(struct ls_scfg_msir *msir)
+{
+	struct ls_scfg_msi *msi_data = msir->msi_data;
+	int i, hwirq;
+
+	if (msir->gic_irq > 0)
+		irq_set_chained_handler_and_data(msir->gic_irq, NULL, NULL);
+
+	for (i = 0; i < MSI_IRQS_PER_MSIR; i++) {
+		hwirq = i << msi_data->cfg->ibs_shift | msir->index;
+		bitmap_set(msi_data->used, hwirq, 1);
+	}
+
+	return 0;
+}
+
+static struct ls_scfg_msi_cfg ls1021_msi_cfg = {
+	.ibs_shift = 3,
+};
+
+static struct ls_scfg_msi_cfg ls1046_msi_cfg = {
+	.ibs_shift = 2,
+};
+
+static const struct of_device_id ls_scfg_msi_id[] = {
+	/* The following two misspelled compatibles are obsolete */
+	{ .compatible = "fsl,1s1021a-msi", .data = &ls1021_msi_cfg},
+	{ .compatible = "fsl,1s1043a-msi", .data = &ls1021_msi_cfg},
+
+	{ .compatible = "fsl,ls1021a-msi", .data = &ls1021_msi_cfg },
+	{ .compatible = "fsl,ls1043a-msi", .data = &ls1021_msi_cfg },
+	{ .compatible = "fsl,ls1046a-msi", .data = &ls1046_msi_cfg },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ls_scfg_msi_id);
+
 static int ls_scfg_msi_probe(struct platform_device *pdev)
 {
+	const struct of_device_id *match;
 	struct ls_scfg_msi *msi_data;
 	struct resource *res;
-	int ret;
+	int i, ret;
+
+	match = of_match_device(ls_scfg_msi_id, &pdev->dev);
+	if (!match)
+		return -ENODEV;
 
 	msi_data = devm_kzalloc(&pdev->dev, sizeof(*msi_data), GFP_KERNEL);
 	if (!msi_data)
 		return -ENOMEM;
+
+	msi_data->cfg = (struct ls_scfg_msi_cfg *) match->data;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	msi_data->regs = devm_ioremap_resource(&pdev->dev, res);
···
 	}
 	msi_data->msiir_addr = res->start;
 
-	msi_data->irq = platform_get_irq(pdev, 0);
-	if (msi_data->irq <= 0) {
-		dev_err(&pdev->dev, "failed to get MSI irq\n");
-		return -ENODEV;
-	}
-
 	msi_data->pdev = pdev;
 	spin_lock_init(&msi_data->lock);
+
+	msi_data->irqs_num = MSI_IRQS_PER_MSIR *
+			     (1 << msi_data->cfg->ibs_shift);
+	msi_data->used = devm_kcalloc(&pdev->dev,
+				    BITS_TO_LONGS(msi_data->irqs_num),
+				    sizeof(*msi_data->used),
+				    GFP_KERNEL);
+	if (!msi_data->used)
+		return -ENOMEM;
+	/*
+	 * Reserve all the hwirqs
+	 * The available hwirqs will be released in ls1_msi_setup_hwirq()
+	 */
+	bitmap_set(msi_data->used, 0, msi_data->irqs_num);
+
+	msi_data->msir_num = of_irq_count(pdev->dev.of_node);
+	msi_data->msir = devm_kcalloc(&pdev->dev, msi_data->msir_num,
+				      sizeof(*msi_data->msir),
+				      GFP_KERNEL);
+	if (!msi_data->msir)
+		return -ENOMEM;
+
+	for (i = 0; i < msi_data->msir_num; i++)
+		ls_scfg_msi_setup_hwirq(msi_data, i);
 
 	ret = ls_scfg_msi_domains_init(msi_data);
 	if (ret)
 		return ret;
-
-	irq_set_chained_handler_and_data(msi_data->irq,
-					 ls_scfg_msi_irq_handler,
-					 msi_data);
 
 	platform_set_drvdata(pdev, msi_data);
 
···
 static int ls_scfg_msi_remove(struct platform_device *pdev)
 {
 	struct ls_scfg_msi *msi_data = platform_get_drvdata(pdev);
+	int i;
 
-	irq_set_chained_handler_and_data(msi_data->irq, NULL, NULL);
+	for (i = 0; i < msi_data->msir_num; i++)
+		ls_scfg_msi_teardown_hwirq(&msi_data->msir[i]);
 
 	irq_domain_remove(msi_data->msi_domain);
 	irq_domain_remove(msi_data->parent);
···
 
 	return 0;
 }
-
-static const struct of_device_id ls_scfg_msi_id[] = {
-	{ .compatible = "fsl,1s1021a-msi", }, /* a typo */
-	{ .compatible = "fsl,1s1043a-msi", }, /* a typo */
-	{ .compatible = "fsl,ls1021a-msi", },
-	{ .compatible = "fsl,ls1043a-msi", },
-	{},
-};
 
 static struct platform_driver ls_scfg_msi_driver = {
 	.driver = {