[PATCH v7 16/37] irqchip: Add SH7751 INTC driver

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

Renesas SH7751 Internal interrupt controller driver.

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>
---
 drivers/irqchip/Kconfig              |   8 +
 drivers/irqchip/Makefile             |   1 +
 drivers/irqchip/irq-renesas-sh7751.c | 282 +++++++++++++++++++++++++++
 3 files changed, 291 insertions(+)
 create mode 100644 drivers/irqchip/irq-renesas-sh7751.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 72c07a12f5e1..33badb5b4f00 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -690,4 +690,12 @@ config SUNPLUS_SP7021_INTC
 	  chained controller, routing all interrupt source in P-Chip to
 	  the primary controller on C-Chip.
 
+config RENESAS_SH7751_INTC
+	bool "Renesas SH7751 Interrupt Controller"
+	depends on SH_DEVICE_TREE || COMPILE_TEST
+	select IRQ_DOMAIN_HIERARCHY
+	help
+	  Support for the Renesas SH7751 On-chip interrupt controller.
+	  And external interrupt encoder for some targets.
+
 endmenu
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index ec4a18380998..51855034a895 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -121,3 +121,4 @@ obj-$(CONFIG_IRQ_IDT3243X)		+= irq-idt3243x.o
 obj-$(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
diff --git a/drivers/irqchip/irq-renesas-sh7751.c b/drivers/irqchip/irq-renesas-sh7751.c
new file mode 100644
index 000000000000..91d6dc3ed04c
--- /dev/null
+++ b/drivers/irqchip/irq-renesas-sh7751.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas SH7751 interrupt controller driver
+ *
+ * Copyright 2023 Yoshinori Sato <ysato@users.sourceforge.jp>
+ */
+
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of.h>
+#include <linux/io.h>
+#include <dt-bindings/interrupt-controller/renesas,sh7751-intc.h>
+
+struct ipr {
+	u16 off;
+	u16 idx;
+};
+
+struct sh7751_intc_priv {
+	const struct ipr *iprmap;
+	void __iomem *base;
+	void __iomem *intpri00;
+	bool	     irlm;
+};
+
+enum {
+	R_ICR         = 0x00,
+	R_IPR         = 0x04,
+	R_INTPRI00    = 0x00,
+	R_INTREQ00    = 0x20,
+	R_INTMSK00    = 0x40,
+	R_INTMSKCLR00 = 0x60,
+};
+
+#define ICR_IRLM BIT(7)
+
+/*
+ * SH7751 IRQ mapping
+ *  IRQ16 - 63: Group0 - IPRA to IPRD
+ *   IRQ16 - 31: external IRL input (ICR.IRLM is 0)
+ *  IRQ80 - 92: Group1 - INTPRI00
+ */
+#define IRQ_START	16
+#define MAX_IRL		(IRQ_START + NR_IRL)
+#define GRP0_IRQ_END	63
+#define GRP1_IRQ_START	80
+#define IRQ_END		92
+
+#define NR_IPRMAP0	(GRP0_IRQ_END - IRQ_START + 1)
+#define NR_IPRMAP1	(IRQ_END - GRP1_IRQ_START)
+#define IPR_PRI_MASK	0x000f
+
+#define IPRA			0
+#define IPRB			4
+#define IPRC			8
+#define IPRD			12
+#define INTPRI00		256
+#define IPR_B12			12
+#define IPR_B8			8
+#define IPR_B4			4
+#define IPR_B0			0
+
+/* SH7751 EVT to IPR mapping table */
+static const struct ipr sh7751_iprmap[] = {
+	[evt2irq(0x240)] = {IPRD, IPR_B12},	/* IRL0 (ICR.IRLM=1) */
+	[evt2irq(0x2a0)] = {IPRD, IPR_B8},	/* IRL1 (ICR.IRLM=1) */
+	[evt2irq(0x300)] = {IPRD, IPR_B4},	/* IRL2 (ICR.IRLM=1) */
+	[evt2irq(0x360)] = {IPRD, IPR_B0},	/* IRL3 (ICR.IRLM=1) */
+	[evt2irq(0x400)] = {IPRA, IPR_B12},	/* TMU0 */
+	[evt2irq(0x420)] = {IPRA, IPR_B8},	/* TMU1 */
+	[evt2irq(0x440)] = {IPRA, IPR_B4},	/* TMU2 TNUI */
+	[evt2irq(0x460)] = {IPRA, IPR_B4},	/* TMU2 TICPI */
+	[evt2irq(0x480)] = {IPRA, IPR_B0},	/* RTC ATI */
+	[evt2irq(0x4a0)] = {IPRA, IPR_B0},	/* RTC PRI */
+	[evt2irq(0x4c0)] = {IPRA, IPR_B0},	/* RTC CUI */
+	[evt2irq(0x4e0)] = {IPRB, IPR_B4},	/* SCI ERI */
+	[evt2irq(0x500)] = {IPRB, IPR_B4},	/* SCI RXI */
+	[evt2irq(0x520)] = {IPRB, IPR_B4},	/* SCI TXI */
+	[evt2irq(0x540)] = {IPRB, IPR_B4},	/* SCI TEI */
+	[evt2irq(0x560)] = {IPRB, IPR_B12},	/* WDT */
+	[evt2irq(0x580)] = {IPRB, IPR_B8},	/* REF RCMI */
+	[evt2irq(0x5a0)] = {IPRB, IPR_B4},	/* REF ROVI */
+	[evt2irq(0x600)] = {IPRC, IPR_B0},	/* H-UDI */
+	[evt2irq(0x620)] = {IPRC, IPR_B12},	/* GPIO */
+	[evt2irq(0x640)] = {IPRC, IPR_B8},	/* DMAC DMTE0 */
+	[evt2irq(0x660)] = {IPRC, IPR_B8},	/* DMAC DMTE1 */
+	[evt2irq(0x680)] = {IPRC, IPR_B8},	/* DMAC DMTE2 */
+	[evt2irq(0x6a0)] = {IPRC, IPR_B8},	/* DMAC DMTE3 */
+	[evt2irq(0x6c0)] = {IPRC, IPR_B8},	/* DMAC DMAE */
+	[evt2irq(0x700)] = {IPRC, IPR_B4},	/* SCIF ERI */
+	[evt2irq(0x720)] = {IPRC, IPR_B4},	/* SCIF RXI */
+	[evt2irq(0x740)] = {IPRC, IPR_B4},	/* SCIF BRI */
+	[evt2irq(0x760)] = {IPRC, IPR_B4},	/* SCIF TXI */
+	[evt2irq(0x780)] = {IPRC, IPR_B8},	/* DMAC DMTE4 */
+	[evt2irq(0x7a0)] = {IPRC, IPR_B8},	/* DMAC DMTE5 */
+	[evt2irq(0x7c0)] = {IPRC, IPR_B8},	/* DMAC DMTE6 */
+	[evt2irq(0x7e0)] = {IPRC, IPR_B8},	/* DMAC DMTE7 */
+	[evt2irq(0xa00)] = {INTPRI00, IPR_B0},	/* PCIC PCISERR */
+	[evt2irq(0xa20)] = {INTPRI00, IPR_B4},	/* PCIC PCIDMA3 */
+	[evt2irq(0xa40)] = {INTPRI00, IPR_B4},	/* PCIC PCIDMA2 */
+	[evt2irq(0xa60)] = {INTPRI00, IPR_B4},	/* PCIC PCIDMA1 */
+	[evt2irq(0xa80)] = {INTPRI00, IPR_B4},	/* PCIC PCIDMA0 */
+	[evt2irq(0xaa0)] = {INTPRI00, IPR_B4},	/* PCIC PCIPWON */
+	[evt2irq(0xac0)] = {INTPRI00, IPR_B4},	/* PCIC PCIPWDWN */
+	[evt2irq(0xae0)] = {INTPRI00, IPR_B4},	/* PCIC PCIERR */
+	[evt2irq(0xb00)] = {INTPRI00, IPR_B8},	/* TMU3 */
+	[evt2irq(0xb80)] = {INTPRI00, IPR_B12},	/* TMU4 */
+};
+
+/*
+ * IPR registers have 4bit priority x 4 entry (16bits)
+ */
+static void update_ipr(struct sh7751_intc_priv *priv, unsigned int irq, u16 pri)
+{
+	const struct ipr *ipr = NULL;
+	void __iomem *ipr_base;
+	unsigned int offset;
+	u16 mask;
+
+	ipr = priv->iprmap + irq;
+	if (irq < GRP1_IRQ_START) {
+		/* Group0 */
+		ipr_base = priv->base + R_IPR;
+		offset = ipr->off;
+	} else {
+		/* Group1 */
+		ipr_base = priv->intpri00;
+		offset = ipr->off - INTPRI00;
+	}
+	mask = ~(IPR_PRI_MASK << ipr->idx);
+	pri = (pri & IPR_PRI_MASK) << ipr->idx;
+	mask &= __raw_readw(ipr_base + offset);
+	__raw_writew(mask | pri, ipr_base + offset);
+}
+
+static inline bool is_valid_irq(unsigned int irq)
+{
+	/* IRQ16 - 63 */
+	if (irq >= IRQ_START && irq < IRQ_START + NR_IPRMAP0)
+		return true;
+	/* IRQ80 - 92 */
+	if (irq >= GRP1_IRQ_START && irq <= IRQ_END)
+		return true;
+	return false;
+}
+
+static inline struct sh7751_intc_priv *irq_data_to_priv(struct irq_data *data)
+{
+	return data->domain->host_data;
+}
+
+/* Interrupt unmask priority is 1, mask priority is 0 */
+#define PRI_ENABLE  1
+#define PRI_DISABLE 0
+static void endisable_irq(struct irq_data *data, bool enable)
+{
+	struct sh7751_intc_priv *priv;
+	unsigned int irq;
+
+	priv = irq_data_to_priv(data);
+
+	irq = irqd_to_hwirq(data);
+	if (!is_valid_irq(irq)) {
+		/* IRQ out of range */
+		pr_warn_once("%s: IRQ %u is out of range\n", __FILE__, irq);
+		return;
+	}
+
+	if (irq <= MAX_IRL && !priv->irlm) {
+		/* IRL encoded external interrupt */
+		/* enable and disable from SR.IMASK */
+		update_sr_imask(irq - IRQ_START, enable);
+	} else {
+		/* Internal peripheral interrupt */
+		/* enable and disable from interrupt priority */
+		update_ipr(priv, irq, enable ? PRI_ENABLE : PRI_DISABLE);
+	}
+}
+
+static void sh7751_mask_irq(struct irq_data *data)
+{
+	endisable_irq(data, false);
+}
+
+static void sh7751_unmask_irq(struct irq_data *data)
+{
+	endisable_irq(data, true);
+}
+
+static const struct irq_chip sh7751_irq_chip = {
+	.name		= "SH7751-INTC",
+	.irq_unmask	= sh7751_unmask_irq,
+	.irq_mask	= sh7751_mask_irq,
+};
+
+static int irq_sh7751_map(struct irq_domain *h, unsigned int virq,
+			  irq_hw_number_t hw_irq_num)
+{
+	irq_set_chip_and_handler(virq, &sh7751_irq_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 irq_sh7751_xlate(struct irq_domain *d, struct device_node *ctrlr,
+			     const u32 *intspec, unsigned int intsize,
+			     unsigned long *out_hwirq, unsigned int *out_type)
+{
+	if (WARN_ON(intsize < 1))
+		return -EINVAL;
+	*out_hwirq = evt2irq(intspec[0]);
+	*out_type = IRQ_TYPE_NONE;
+	return 0;
+}
+
+static const struct irq_domain_ops irq_ops = {
+	.map    = irq_sh7751_map,
+	.xlate  = irq_sh7751_xlate,
+};
+
+static int __init shintc_of_init(struct device_node *intc, struct device_node *parent,
+				 const struct ipr *iprmap)
+{
+	struct sh7751_intc_priv *priv;
+	void __iomem *base, *base2;
+	struct irq_domain *domain;
+	u16 icr;
+	int ret;
+
+	priv = kzalloc(sizeof(struct sh7751_intc_priv), GFP_KERNEL);
+	if (priv == NULL)
+		return -ENOMEM;
+
+	base = of_iomap(intc, 0);
+	base2 = of_iomap(intc, 1);
+	if (!base || !base2) {
+		pr_err("%pOFP: Invalid register definition\n", intc);
+		ret = -EINVAL;
+		goto error;
+	}
+
+	priv->base = base;
+	priv->intpri00 = base2;
+	priv->iprmap = iprmap;
+
+	if (of_property_read_bool(intc, "renesas,irlm")) {
+		priv->irlm = true;
+		icr = __raw_readw(priv->base + R_ICR);
+		icr |= ICR_IRLM;
+		__raw_writew(icr, priv->base + R_ICR);
+	}
+
+	domain = irq_domain_add_linear(intc, NR_IRQS, &irq_ops, priv);
+	if (domain == NULL) {
+		pr_err("%pOFP: cannot initialize irq domain\n", intc);
+		ret = -ENOMEM;
+		goto error;
+	}
+
+	irq_set_default_host(domain);
+	pr_info("%pOFP: SH7751 Interrupt controller (%s external IRQ)",
+		intc, priv->irlm ? "4 lines" : "15 level");
+	return 0;
+
+error:
+	if (base)
+		iounmap(base);
+	if (base2)
+		iounmap(base);
+	kfree(priv);
+	return ret;
+}
+
+static int __init sh7751_intc_of_init(struct device_node *intc,
+				      struct device_node *parent)
+{
+	return shintc_of_init(intc, parent, sh7751_iprmap);
+}
+
+IRQCHIP_DECLARE(sh_7751_intc, "renesas,sh7751-intc", sh7751_intc_of_init);
-- 
2.39.2