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 <Minghuan.Lian@nxp.com>
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 130 insertions, 35 deletions

diff --git a/drivers/irqchip/irq-ls-scfg-msi.c b/drivers/irqchip/irq-ls-scfg-msi.c
index cef67cc5c0f2..0b1f34ddab00 100644
--- a/drivers/irqchip/irq-ls-scfg-msi.c
+++ b/drivers/irqchip/irq-ls-scfg-msi.c
@@ -17,13 +17,24 @@
 #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;
@@ -32,8 +43,11 @@ struct ls_scfg_msi {
         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 = {
@@ -55,7 +69,7 @@ static void ls_scfg_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
 
         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,
@@ -81,8 +95,8 @@ static int ls_scfg_msi_domain_irq_alloc(struct irq_domain *domain,
         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;
@@ -106,7 +120,7 @@ static void ls_scfg_msi_domain_irq_free(struct irq_domain *domain,
         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;
         }
@@ -123,15 +137,17 @@ static const struct irq_domain_ops ls_scfg_msi_domain_ops = {
 
 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);
         }
@@ -143,7 +159,7 @@ static int ls_scfg_msi_domains_init(struct ls_scfg_msi *msi_data)
 {
         /* 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) {
@@ -164,16 +180,87 @@ static int ls_scfg_msi_domains_init(struct ls_scfg_msi *msi_data)
         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);
         if (IS_ERR(msi_data->regs)) {
@@ -182,23 +269,37 @@ static int ls_scfg_msi_probe(struct platform_device *pdev)
         }
         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);
 
         return 0;
@@ -207,8 +308,10 @@ static int ls_scfg_msi_probe(struct platform_device *pdev)
 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);
@@ -218,14 +321,6 @@ static int ls_scfg_msi_remove(struct platform_device *pdev)
         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 = {
                 .name = "ls-scfg-msi",