summaryrefslogtreecommitdiffstats
path: root/arch/mips/alchemy/devboards/bcsr.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/mips/alchemy/devboards/bcsr.c')
-rw-r--r--arch/mips/alchemy/devboards/bcsr.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/mips/alchemy/devboards/bcsr.c b/arch/mips/alchemy/devboards/bcsr.c
new file mode 100644
index 0000000000..8df0ccdc92
--- /dev/null
+++ b/arch/mips/alchemy/devboards/bcsr.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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/irqchip/chained_irq.h>
+#include <linux/init.h>
+#include <linux/export.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(struct irq_desc *d)
+{
+ unsigned short bisr = __raw_readw(bcsr_virt + BCSR_REG_INTSTAT);
+ struct irq_chip *chip = irq_desc_get_chip(d);
+
+ chained_irq_enter(chip, d);
+ generic_handle_irq(bcsr_csc_base + __ffs(bisr));
+ chained_irq_exit(chip, d);
+}
+
+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);
+}