[PATCH v7 18/37] irqchip: SH7751 external interrupt encoder with enable gate.

[Yoshinori Sato <ysato@users.sourceforge.jp>]

SH7751 have 15 level external interrupt.
It is typically connected to the CPU through a priority encoder
that can suppress requests.
This driver provides a way to control those hardware with irqchip.

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
---
 drivers/irqchip/Kconfig                 |   7 +
 drivers/irqchip/Makefile                |   2 +
 drivers/irqchip/irq-renesas-sh7751irl.c | 221 ++++++++++++++++++++++++
 3 files changed, 230 insertions(+)
 create mode 100644 drivers/irqchip/irq-renesas-sh7751irl.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 33badb5b4f00..7670fcd6757d 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -698,4 +698,11 @@ config RENESAS_SH7751_INTC
 	  Support for the Renesas SH7751 On-chip interrupt controller.
 	  And external interrupt encoder for some targets.
 
+config RENESAS_SH7751IRL_INTC
+	bool "Renesas SH7751 based target IRL encoder support."
+	depends on RENESAS_SH7751_INTC
+	help
+	  Support for External Interrupt encoder
+	  on the some Renesas SH7751 based target.
+
 endmenu
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 51855034a895..bc21d65441f2 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -122,3 +122,5 @@ obj-$(CONFIG_APPLE_AIC)			+= irq-apple-aic.o
 obj-$(CONFIG_MCHP_EIC)			+= irq-mchp-eic.o
 obj-$(CONFIG_SUNPLUS_SP7021_INTC)	+= irq-sp7021-intc.o
 obj-$(CONFIG_RENESAS_SH7751_INTC)	+= irq-renesas-sh7751.o
+obj-$(CONFIG_RENESAS_SH7751IRL_INTC)	+= irq-renesas-sh7751irl.o
+
diff --git a/drivers/irqchip/irq-renesas-sh7751irl.c b/drivers/irqchip/irq-renesas-sh7751irl.c
new file mode 100644
index 000000000000..5990f2cd9a3d
--- /dev/null
+++ b/drivers/irqchip/irq-renesas-sh7751irl.c
@@ -0,0 +1,221 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SH7751 based board external interrupt level encoder driver
+ * (Renesas RTS7751R2D / IO DATA DEVICE LANDISK, USL-5P)
+ *
+ * Copyright (C) 2023 Yoshinori Sato
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+
+struct sh7751irl_intc_priv {
+	struct irq_domain *irq_domain;
+	void __iomem	  *base;
+	unsigned int	  width;
+	bool		  invert;
+	u32		  enable_bit[NR_IRL];
+};
+
+static inline unsigned long get_reg(void __iomem *addr, unsigned int w)
+{
+	switch (w) {
+	case 8:
+		return __raw_readb(addr);
+	case 16:
+		return __raw_readw(addr);
+	case 32:
+		return __raw_readl(addr);
+	default:
+		/* The size is checked when reading the properties. */
+		pr_err("%s: Invalid width %d", __FILE__, w);
+		return 0;
+	}
+}
+
+static inline void set_reg(void __iomem *addr, unsigned int w, unsigned long val)
+{
+	switch (w) {
+	case 8:
+		__raw_writeb(val, addr);
+		break;
+	case 16:
+		__raw_writew(val, addr);
+		break;
+	case 32:
+		__raw_writel(val, addr);
+		break;
+	default:
+		pr_err("%s: Invalid width %d", __FILE__, w);
+	}
+}
+
+static inline struct sh7751irl_intc_priv *irq_data_to_priv(struct irq_data *data)
+{
+	return data->domain->host_data;
+}
+
+static void irl_endisable(struct irq_data *data, unsigned int enable)
+{
+	struct sh7751irl_intc_priv *priv;
+	unsigned long val;
+	unsigned int irl;
+
+	priv = irq_data_to_priv(data);
+	irl = irqd_to_hwirq(data) - IRL_BASE_IRQ;
+
+	if (irl < NR_IRL && priv->enable_bit[irl] < priv->width) {
+		if (priv->invert)
+			enable = !enable;
+
+		val = get_reg(priv->base, priv->width);
+		if (enable)
+			set_bit(priv->enable_bit[irl], &val);
+		else
+			clear_bit(priv->enable_bit[irl], &val);
+		set_reg(priv->base, priv->width, val);
+	} else {
+		pr_err("%s: Invalid register define in IRL %u", __FILE__, irl);
+	}
+}
+
+static void sh7751irl_intc_disable_irq(struct irq_data *data)
+{
+	irl_endisable(data, 0);
+}
+
+static void sh7751irl_intc_enable_irq(struct irq_data *data)
+{
+	irl_endisable(data, 1);
+}
+
+static struct irq_chip sh7751irl_intc_chip = {
+	.name		= "SH7751IRL-INTC",
+	.irq_enable	= sh7751irl_intc_enable_irq,
+	.irq_disable	= sh7751irl_intc_disable_irq,
+};
+
+static int sh7751irl_intc_map(struct irq_domain *h, unsigned int virq,
+			       irq_hw_number_t hw_irq_num)
+{
+	irq_set_chip_and_handler(virq, &sh7751irl_intc_chip, handle_level_irq);
+	irq_get_irq_data(virq)->chip_data = h->host_data;
+	irq_modify_status(virq, IRQ_NOREQUEST, IRQ_NOPROBE);
+	return 0;
+}
+
+static int sh7751irl_intc_translate(struct irq_domain *domain,
+			       struct irq_fwspec *fwspec, unsigned long *hwirq,
+			       unsigned int *type)
+{
+	if (fwspec->param[0] > NR_IRL)
+		return -EINVAL;
+
+	switch (fwspec->param_count) {
+	case 2:
+		*type = fwspec->param[1];
+		fallthrough;
+	case 1:
+		*hwirq = fwspec->param[0] + IRL_BASE_IRQ;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static const struct irq_domain_ops sh7751irl_intc_domain_ops = {
+	.map = sh7751irl_intc_map,
+	.translate = sh7751irl_intc_translate,
+};
+
+static int __init load_irl_bit(struct device_node *node, struct sh7751irl_intc_priv *priv)
+{
+	struct property *enable_map;
+	const __be32 *p;
+	u32 nr_bits, bit;
+	u32 irl;
+	int ret;
+
+	/* Fill in unused */
+	memset(priv->enable_bit, ~0, sizeof(priv->enable_bit));
+
+	enable_map = of_find_property(node, "renesas,enable-reg", &nr_bits);
+	if (IS_ERR(enable_map))
+		return PTR_ERR(enable_map);
+
+	nr_bits /= sizeof(u32);
+	if (nr_bits > priv->width)
+		return -EINVAL;
+
+	ret = nr_bits;
+	p = NULL;
+	for (bit = nr_bits; bit > 0; bit--) {
+		p = of_prop_next_u32(enable_map, p, &irl);
+		if (p == NULL || irl > NR_IRL)
+			return -EINVAL;
+		if (irl == NR_IRL)
+			/* IRL15 is unassined bit */
+			continue;
+		priv->enable_bit[irl] = bit - 1;
+	}
+	return ret;
+}
+
+static int __init sh7751irl_init(struct device_node *node, struct device_node *parent)
+{
+	struct sh7751irl_intc_priv *priv;
+	struct resource res;
+	struct irq_domain *d;
+	void __iomem *base;
+	int ret = 0;
+
+	if (of_address_to_resource(node, 0, &res))
+		return -EINVAL;
+	if (resource_size(&res) > 4)
+		return -EINVAL;
+
+	base = ioremap(res.start, resource_size(&res));
+	if (!base)
+		return -EINVAL;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->base = base;
+	priv->width = 8 << resource_size(&res);
+
+	ret = load_irl_bit(node, priv);
+	if (ret < 0) {
+		pr_err("%pOFP: Invalid register define.\n", node);
+		goto error;
+	}
+
+	d = irq_domain_add_tree(node, &sh7751irl_intc_domain_ops, priv);
+	if (d == NULL) {
+		pr_err("%pOFP: cannot initialize irq domain\n", node);
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	priv->irq_domain = d;
+	irq_domain_update_bus_token(d, DOMAIN_BUS_WIRED);
+	pr_info("%pOFP: SH7751 External Interrupt encoder (input=%d)", node, ret);
+	return 0;
+error:
+	kfree(priv);
+	return ret;
+}
+
+IRQCHIP_DECLARE(renesas_sh7751_irl, "renesas,sh7751-irl-ext", sh7751irl_init);
-- 
2.39.2