From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/mips/alchemy/devboards/bcsr.c | 143 +++++++++++++++++++++++++++++++++++++
 1 file changed, 143 insertions(+)
 create mode 100644 arch/mips/alchemy/devboards/bcsr.c

(limited to 'arch/mips/alchemy/devboards/bcsr.c')

diff --git a/arch/mips/alchemy/devboards/bcsr.c b/arch/mips/alchemy/devboards/bcsr.c
new file mode 100644
index 000000000..c98c9ea33
--- /dev/null
+++ b/arch/mips/alchemy/devboards/bcsr.c
@@ -0,0 +1,143 @@
+/*
+ * bcsr.h -- Db1xxx/Pb1xxx Devboard CPLD registers ("BCSR") abstraction.
+ *
+ * All Alchemy development boards (except, of course, the weird PB1000)
+ * have a few registers in a CPLD with standardised layout; they mostly
+ * only differ in base address.
+ * All registers are 16bits wide with 32bit spacing.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/irq.h>
+#include <asm/addrspace.h>
+#include <asm/io.h>
+#include <asm/mach-db1x00/bcsr.h>
+
+static struct bcsr_reg {
+	void __iomem *raddr;
+	spinlock_t lock;
+} bcsr_regs[BCSR_CNT];
+
+static void __iomem *bcsr_virt; /* KSEG1 addr of BCSR base */
+static int bcsr_csc_base;	/* linux-irq of first cascaded irq */
+
+void __init bcsr_init(unsigned long bcsr1_phys, unsigned long bcsr2_phys)
+{
+	int i;
+
+	bcsr1_phys = KSEG1ADDR(CPHYSADDR(bcsr1_phys));
+	bcsr2_phys = KSEG1ADDR(CPHYSADDR(bcsr2_phys));
+
+	bcsr_virt = (void __iomem *)bcsr1_phys;
+
+	for (i = 0; i < BCSR_CNT; i++) {
+		if (i >= BCSR_HEXLEDS)
+			bcsr_regs[i].raddr = (void __iomem *)bcsr2_phys +
+					(0x04 * (i - BCSR_HEXLEDS));
+		else
+			bcsr_regs[i].raddr = (void __iomem *)bcsr1_phys +
+					(0x04 * i);
+
+		spin_lock_init(&bcsr_regs[i].lock);
+	}
+}
+
+unsigned short bcsr_read(enum bcsr_id reg)
+{
+	unsigned short r;
+	unsigned long flags;
+
+	spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
+	r = __raw_readw(bcsr_regs[reg].raddr);
+	spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
+	return r;
+}
+EXPORT_SYMBOL_GPL(bcsr_read);
+
+void bcsr_write(enum bcsr_id reg, unsigned short val)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
+	__raw_writew(val, bcsr_regs[reg].raddr);
+	wmb();
+	spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
+}
+EXPORT_SYMBOL_GPL(bcsr_write);
+
+void bcsr_mod(enum bcsr_id reg, unsigned short clr, unsigned short set)
+{
+	unsigned short r;
+	unsigned long flags;
+
+	spin_lock_irqsave(&bcsr_regs[reg].lock, flags);
+	r = __raw_readw(bcsr_regs[reg].raddr);
+	r &= ~clr;
+	r |= set;
+	__raw_writew(r, bcsr_regs[reg].raddr);
+	wmb();
+	spin_unlock_irqrestore(&bcsr_regs[reg].lock, flags);
+}
+EXPORT_SYMBOL_GPL(bcsr_mod);
+
+/*
+ * DB1200/PB1200 CPLD IRQ muxer
+ */
+static void bcsr_csc_handler(unsigned int irq, struct irq_desc *d)
+{
+	unsigned short bisr = __raw_readw(bcsr_virt + BCSR_REG_INTSTAT);
+
+	disable_irq_nosync(irq);
+	generic_handle_irq(bcsr_csc_base + __ffs(bisr));
+	enable_irq(irq);
+}
+
+static void bcsr_irq_mask(struct irq_data *d)
+{
+	unsigned short v = 1 << (d->irq - bcsr_csc_base);
+	__raw_writew(v, bcsr_virt + BCSR_REG_MASKCLR);
+	wmb();
+}
+
+static void bcsr_irq_maskack(struct irq_data *d)
+{
+	unsigned short v = 1 << (d->irq - bcsr_csc_base);
+	__raw_writew(v, bcsr_virt + BCSR_REG_MASKCLR);
+	__raw_writew(v, bcsr_virt + BCSR_REG_INTSTAT);	/* ack */
+	wmb();
+}
+
+static void bcsr_irq_unmask(struct irq_data *d)
+{
+	unsigned short v = 1 << (d->irq - bcsr_csc_base);
+	__raw_writew(v, bcsr_virt + BCSR_REG_MASKSET);
+	wmb();
+}
+
+static struct irq_chip bcsr_irq_type = {
+	.name		= "CPLD",
+	.irq_mask	= bcsr_irq_mask,
+	.irq_mask_ack	= bcsr_irq_maskack,
+	.irq_unmask	= bcsr_irq_unmask,
+};
+
+void __init bcsr_init_irq(int csc_start, int csc_end, int hook_irq)
+{
+	unsigned int irq;
+
+	/* mask & enable & ack all */
+	__raw_writew(0xffff, bcsr_virt + BCSR_REG_MASKCLR);
+	__raw_writew(0xffff, bcsr_virt + BCSR_REG_INTSET);
+	__raw_writew(0xffff, bcsr_virt + BCSR_REG_INTSTAT);
+	wmb();
+
+	bcsr_csc_base = csc_start;
+
+	for (irq = csc_start; irq <= csc_end; irq++)
+		irq_set_chip_and_handler_name(irq, &bcsr_irq_type,
+					      handle_level_irq, "level");
+
+	irq_set_chained_handler(hook_irq, bcsr_csc_handler);
+}
-- 
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