Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 166 insertions, 0 deletions

diff --git a/arch/m68k/mac/psc.c b/arch/m68k/mac/psc.c
new file mode 100644
index 0000000000..0d0965b19c
--- /dev/null
+++ b/arch/m68k/mac/psc.c
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *	Apple Peripheral System Controller (PSC)
+ *
+ *	The PSC is used on the AV Macs to control IO functions not handled
+ *	by the VIAs (Ethernet, DSP, SCC).
+ *
+ * TO DO:
+ *
+ * Try to figure out what's going on in pIFR5 and pIFR6. There seem to be
+ * persisant interrupt conditions in those registers and I have no idea what
+ * they are. Granted it doesn't affect since we're not enabling any interrupts
+ * on those levels at the moment, but it would be nice to know. I have a feeling
+ * they aren't actually interrupt lines but data lines (to the DSP?)
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+
+#include <asm/traps.h>
+#include <asm/macintosh.h>
+#include <asm/macints.h>
+#include <asm/mac_psc.h>
+
+#define DEBUG_PSC
+
+volatile __u8 *psc;
+EXPORT_SYMBOL_GPL(psc);
+
+/*
+ * Debugging dump, used in various places to see what's going on.
+ */
+
+static void psc_debug_dump(void)
+{
+	int	i;
+
+	if (!psc)
+		return;
+
+	for (i = 0x30 ; i < 0x70 ; i += 0x10) {
+		printk(KERN_DEBUG "PSC #%d:  IFR = 0x%02X IER = 0x%02X\n",
+			i >> 4,
+			(int) psc_read_byte(pIFRbase + i),
+			(int) psc_read_byte(pIERbase + i));
+	}
+}
+
+/*
+ * Try to kill all DMA channels on the PSC. Not sure how this his
+ * supposed to work; this is code lifted from macmace.c and then
+ * expanded to cover what I think are the other 7 channels.
+ */
+
+static __init void psc_dma_die_die_die(void)
+{
+	int i;
+
+	for (i = 0 ; i < 9 ; i++) {
+		psc_write_word(PSC_CTL_BASE + (i << 4), 0x8800);
+		psc_write_word(PSC_CTL_BASE + (i << 4), 0x1000);
+		psc_write_word(PSC_CMD_BASE + (i << 5), 0x1100);
+		psc_write_word(PSC_CMD_BASE + (i << 5) + 0x10, 0x1100);
+	}
+}
+
+/*
+ * Initialize the PSC. For now this just involves shutting down all
+ * interrupt sources using the IERs.
+ */
+
+void __init psc_init(void)
+{
+	int i;
+
+	if (macintosh_config->ident != MAC_MODEL_C660
+	 && macintosh_config->ident != MAC_MODEL_Q840)
+	{
+		psc = NULL;
+		return;
+	}
+
+	/*
+	 * The PSC is always at the same spot, but using psc
+	 * keeps things consistent with the psc_xxxx functions.
+	 */
+
+	psc = (void *) PSC_BASE;
+
+	pr_debug("PSC detected at %p\n", psc);
+
+	psc_dma_die_die_die();
+
+#ifdef DEBUG_PSC
+	psc_debug_dump();
+#endif
+	/*
+	 * Mask and clear all possible interrupts
+	 */
+
+	for (i = 0x30 ; i < 0x70 ; i += 0x10) {
+		psc_write_byte(pIERbase + i, 0x0F);
+		psc_write_byte(pIFRbase + i, 0x0F);
+	}
+}
+
+/*
+ * PSC interrupt handler. It's a lot like the VIA interrupt handler.
+ */
+
+static void psc_irq(struct irq_desc *desc)
+{
+	unsigned int offset = (unsigned int)irq_desc_get_handler_data(desc);
+	unsigned int irq = irq_desc_get_irq(desc);
+	int pIFR	= pIFRbase + offset;
+	int pIER	= pIERbase + offset;
+	int irq_num;
+	unsigned char irq_bit, events;
+
+	events = psc_read_byte(pIFR) & psc_read_byte(pIER) & 0xF;
+	if (!events)
+		return;
+
+	irq_num = irq << 3;
+	irq_bit = 1;
+	do {
+		if (events & irq_bit) {
+			psc_write_byte(pIFR, irq_bit);
+			generic_handle_irq(irq_num);
+		}
+		irq_num++;
+		irq_bit <<= 1;
+	} while (events >= irq_bit);
+}
+
+/*
+ * Register the PSC interrupt dispatchers for autovector interrupts 3-6.
+ */
+
+void __init psc_register_interrupts(void)
+{
+	irq_set_chained_handler_and_data(IRQ_AUTO_3, psc_irq, (void *)0x30);
+	irq_set_chained_handler_and_data(IRQ_AUTO_4, psc_irq, (void *)0x40);
+	irq_set_chained_handler_and_data(IRQ_AUTO_5, psc_irq, (void *)0x50);
+	irq_set_chained_handler_and_data(IRQ_AUTO_6, psc_irq, (void *)0x60);
+}
+
+void psc_irq_enable(int irq) {
+	int irq_src	= IRQ_SRC(irq);
+	int irq_idx	= IRQ_IDX(irq);
+	int pIER	= pIERbase + (irq_src << 4);
+
+	psc_write_byte(pIER, (1 << irq_idx) | 0x80);
+}
+
+void psc_irq_disable(int irq) {
+	int irq_src	= IRQ_SRC(irq);
+	int irq_idx	= IRQ_IDX(irq);
+	int pIER	= pIERbase + (irq_src << 4);
+
+	psc_write_byte(pIER, 1 << irq_idx);
+}