633 lines
16 KiB
C
633 lines
16 KiB
C
/*
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* Device driver for the via-cuda on Apple Powermacs.
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*
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* The VIA (versatile interface adapter) interfaces to the CUDA,
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* a 6805 microprocessor core which controls the ADB (Apple Desktop
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* Bus) which connects to the keyboard and mouse. The CUDA also
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* controls system power and the RTC (real time clock) chip.
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*
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* Copyright (C) 1996 Paul Mackerras.
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*/
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#include <stdarg.h>
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#include <linux/types.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/delay.h>
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#include <linux/adb.h>
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#include <linux/cuda.h>
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#include <linux/spinlock.h>
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#include <linux/interrupt.h>
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#ifdef CONFIG_PPC
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#include <asm/prom.h>
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#include <asm/machdep.h>
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#else
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#include <asm/macintosh.h>
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#include <asm/macints.h>
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#include <asm/mac_via.h>
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#endif
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#include <asm/io.h>
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#include <asm/system.h>
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#include <linux/init.h>
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static volatile unsigned char __iomem *via;
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static DEFINE_SPINLOCK(cuda_lock);
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/* VIA registers - spaced 0x200 bytes apart */
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#define RS 0x200 /* skip between registers */
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#define B 0 /* B-side data */
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#define A RS /* A-side data */
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#define DIRB (2*RS) /* B-side direction (1=output) */
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#define DIRA (3*RS) /* A-side direction (1=output) */
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#define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */
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#define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */
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#define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */
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#define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */
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#define T2CL (8*RS) /* Timer 2 ctr/latch (low 8 bits) */
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#define T2CH (9*RS) /* Timer 2 counter (high 8 bits) */
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#define SR (10*RS) /* Shift register */
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#define ACR (11*RS) /* Auxiliary control register */
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#define PCR (12*RS) /* Peripheral control register */
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#define IFR (13*RS) /* Interrupt flag register */
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#define IER (14*RS) /* Interrupt enable register */
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#define ANH (15*RS) /* A-side data, no handshake */
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/* Bits in B data register: all active low */
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#define TREQ 0x08 /* Transfer request (input) */
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#define TACK 0x10 /* Transfer acknowledge (output) */
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#define TIP 0x20 /* Transfer in progress (output) */
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/* Bits in ACR */
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#define SR_CTRL 0x1c /* Shift register control bits */
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#define SR_EXT 0x0c /* Shift on external clock */
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#define SR_OUT 0x10 /* Shift out if 1 */
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/* Bits in IFR and IER */
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#define IER_SET 0x80 /* set bits in IER */
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#define IER_CLR 0 /* clear bits in IER */
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#define SR_INT 0x04 /* Shift register full/empty */
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static enum cuda_state {
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idle,
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sent_first_byte,
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sending,
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reading,
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read_done,
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awaiting_reply
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} cuda_state;
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static struct adb_request *current_req;
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static struct adb_request *last_req;
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static unsigned char cuda_rbuf[16];
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static unsigned char *reply_ptr;
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static int reading_reply;
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static int data_index;
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static int cuda_irq;
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#ifdef CONFIG_PPC
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static struct device_node *vias;
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#endif
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static int cuda_fully_inited;
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#ifdef CONFIG_ADB
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static int cuda_probe(void);
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static int cuda_init(void);
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static int cuda_send_request(struct adb_request *req, int sync);
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static int cuda_adb_autopoll(int devs);
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static int cuda_reset_adb_bus(void);
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#endif /* CONFIG_ADB */
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static int cuda_init_via(void);
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static void cuda_start(void);
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static irqreturn_t cuda_interrupt(int irq, void *arg);
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static void cuda_input(unsigned char *buf, int nb);
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void cuda_poll(void);
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static int cuda_write(struct adb_request *req);
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int cuda_request(struct adb_request *req,
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void (*done)(struct adb_request *), int nbytes, ...);
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#ifdef CONFIG_ADB
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struct adb_driver via_cuda_driver = {
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"CUDA",
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cuda_probe,
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cuda_init,
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cuda_send_request,
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cuda_adb_autopoll,
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cuda_poll,
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cuda_reset_adb_bus
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};
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#endif /* CONFIG_ADB */
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#ifdef CONFIG_PPC
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int __init find_via_cuda(void)
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{
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struct adb_request req;
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phys_addr_t taddr;
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const u32 *reg;
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int err;
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if (vias != 0)
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return 1;
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vias = of_find_node_by_name(NULL, "via-cuda");
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if (vias == 0)
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return 0;
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reg = of_get_property(vias, "reg", NULL);
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if (reg == NULL) {
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printk(KERN_ERR "via-cuda: No \"reg\" property !\n");
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goto fail;
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}
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taddr = of_translate_address(vias, reg);
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if (taddr == 0) {
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printk(KERN_ERR "via-cuda: Can't translate address !\n");
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goto fail;
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}
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via = ioremap(taddr, 0x2000);
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if (via == NULL) {
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printk(KERN_ERR "via-cuda: Can't map address !\n");
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goto fail;
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}
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cuda_state = idle;
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sys_ctrler = SYS_CTRLER_CUDA;
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err = cuda_init_via();
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if (err) {
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printk(KERN_ERR "cuda_init_via() failed\n");
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via = NULL;
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return 0;
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}
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/* Clear and enable interrupts, but only on PPC. On 68K it's done */
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/* for us by the main VIA driver in arch/m68k/mac/via.c */
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out_8(&via[IFR], 0x7f); /* clear interrupts by writing 1s */
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out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
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/* enable autopoll */
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cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1);
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while (!req.complete)
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cuda_poll();
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return 1;
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fail:
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of_node_put(vias);
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vias = NULL;
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return 0;
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}
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#endif /* CONFIG_PPC */
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static int __init via_cuda_start(void)
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{
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if (via == NULL)
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return -ENODEV;
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#ifdef CONFIG_MAC
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cuda_irq = IRQ_MAC_ADB;
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#else /* CONFIG_MAC */
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cuda_irq = irq_of_parse_and_map(vias, 0);
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if (cuda_irq == NO_IRQ) {
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printk(KERN_ERR "via-cuda: can't map interrupts for %s\n",
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vias->full_name);
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return -ENODEV;
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}
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#endif /* CONFIG_MAC */
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if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) {
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printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq);
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return -EAGAIN;
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}
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printk("Macintosh CUDA driver v0.5 for Unified ADB.\n");
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cuda_fully_inited = 1;
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return 0;
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}
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device_initcall(via_cuda_start);
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#ifdef CONFIG_ADB
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static int
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cuda_probe(void)
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{
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#ifdef CONFIG_PPC
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if (sys_ctrler != SYS_CTRLER_CUDA)
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return -ENODEV;
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#else
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if (macintosh_config->adb_type != MAC_ADB_CUDA)
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return -ENODEV;
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via = via1;
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#endif
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return 0;
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}
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static int __init
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cuda_init(void)
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{
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#ifdef CONFIG_PPC
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if (via == NULL)
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return -ENODEV;
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return 0;
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#else
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int err = cuda_init_via();
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if (err) {
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printk(KERN_ERR "cuda_init_via() failed\n");
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return -ENODEV;
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}
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out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */
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return via_cuda_start();
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#endif
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}
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#endif /* CONFIG_ADB */
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#define WAIT_FOR(cond, what) \
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do { \
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int x; \
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for (x = 1000; !(cond); --x) { \
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if (x == 0) { \
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printk("Timeout waiting for " what "\n"); \
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return -ENXIO; \
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} \
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udelay(100); \
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} \
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} while (0)
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static int
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cuda_init_via(void)
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{
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out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */
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out_8(&via[B], in_8(&via[B]) | TACK | TIP); /* negate them */
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out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */
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(void)in_8(&via[SR]); /* clear any left-over data */
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#ifdef CONFIG_PPC
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out_8(&via[IER], 0x7f); /* disable interrupts from VIA */
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(void)in_8(&via[IER]);
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#else
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out_8(&via[IER], SR_INT); /* disable SR interrupt from VIA */
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#endif
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/* delay 4ms and then clear any pending interrupt */
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mdelay(4);
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(void)in_8(&via[SR]);
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out_8(&via[IFR], SR_INT);
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/* sync with the CUDA - assert TACK without TIP */
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out_8(&via[B], in_8(&via[B]) & ~TACK);
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/* wait for the CUDA to assert TREQ in response */
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WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync");
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/* wait for the interrupt and then clear it */
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WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)");
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(void)in_8(&via[SR]);
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out_8(&via[IFR], SR_INT);
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/* finish the sync by negating TACK */
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out_8(&via[B], in_8(&via[B]) | TACK);
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/* wait for the CUDA to negate TREQ and the corresponding interrupt */
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WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)");
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WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)");
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(void)in_8(&via[SR]);
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out_8(&via[IFR], SR_INT);
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out_8(&via[B], in_8(&via[B]) | TIP); /* should be unnecessary */
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return 0;
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}
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#ifdef CONFIG_ADB
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/* Send an ADB command */
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static int
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cuda_send_request(struct adb_request *req, int sync)
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{
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int i;
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if ((via == NULL) || !cuda_fully_inited) {
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req->complete = 1;
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return -ENXIO;
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}
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req->reply_expected = 1;
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i = cuda_write(req);
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if (i)
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return i;
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if (sync) {
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while (!req->complete)
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cuda_poll();
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}
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return 0;
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}
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/* Enable/disable autopolling */
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static int
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cuda_adb_autopoll(int devs)
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{
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struct adb_request req;
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if ((via == NULL) || !cuda_fully_inited)
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return -ENXIO;
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cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0));
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while (!req.complete)
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cuda_poll();
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return 0;
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}
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/* Reset adb bus - how do we do this?? */
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static int
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cuda_reset_adb_bus(void)
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{
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struct adb_request req;
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if ((via == NULL) || !cuda_fully_inited)
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return -ENXIO;
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cuda_request(&req, NULL, 2, ADB_PACKET, 0); /* maybe? */
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while (!req.complete)
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cuda_poll();
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return 0;
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}
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#endif /* CONFIG_ADB */
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/* Construct and send a cuda request */
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int
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cuda_request(struct adb_request *req, void (*done)(struct adb_request *),
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int nbytes, ...)
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{
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va_list list;
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int i;
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if (via == NULL) {
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req->complete = 1;
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return -ENXIO;
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}
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req->nbytes = nbytes;
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req->done = done;
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va_start(list, nbytes);
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for (i = 0; i < nbytes; ++i)
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req->data[i] = va_arg(list, int);
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va_end(list);
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req->reply_expected = 1;
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return cuda_write(req);
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}
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static int
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cuda_write(struct adb_request *req)
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{
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unsigned long flags;
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if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) {
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req->complete = 1;
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return -EINVAL;
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}
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req->next = NULL;
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req->sent = 0;
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req->complete = 0;
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req->reply_len = 0;
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spin_lock_irqsave(&cuda_lock, flags);
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if (current_req != 0) {
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last_req->next = req;
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last_req = req;
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} else {
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current_req = req;
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last_req = req;
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if (cuda_state == idle)
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cuda_start();
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}
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spin_unlock_irqrestore(&cuda_lock, flags);
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return 0;
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}
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static void
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cuda_start(void)
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{
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struct adb_request *req;
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/* assert cuda_state == idle */
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/* get the packet to send */
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req = current_req;
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if (req == 0)
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return;
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if ((in_8(&via[B]) & TREQ) == 0)
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return; /* a byte is coming in from the CUDA */
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/* set the shift register to shift out and send a byte */
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out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT);
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out_8(&via[SR], req->data[0]);
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out_8(&via[B], in_8(&via[B]) & ~TIP);
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cuda_state = sent_first_byte;
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}
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void
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cuda_poll(void)
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{
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/* cuda_interrupt only takes a normal lock, we disable
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* interrupts here to avoid re-entering and thus deadlocking.
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*/
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disable_irq(cuda_irq);
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cuda_interrupt(0, NULL);
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enable_irq(cuda_irq);
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}
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static irqreturn_t
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cuda_interrupt(int irq, void *arg)
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{
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int status;
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struct adb_request *req = NULL;
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unsigned char ibuf[16];
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int ibuf_len = 0;
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int complete = 0;
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spin_lock(&cuda_lock);
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/* On powermacs, this handler is registered for the VIA IRQ. But it uses
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* just the shift register IRQ -- other VIA interrupt sources are disabled.
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* On m68k macs, the VIA IRQ sources are dispatched individually. Unless
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* we are polling, the shift register IRQ flag has already been cleared.
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*/
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#ifdef CONFIG_MAC
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if (!arg)
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#endif
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{
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if ((in_8(&via[IFR]) & SR_INT) == 0) {
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spin_unlock(&cuda_lock);
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return IRQ_NONE;
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} else {
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out_8(&via[IFR], SR_INT);
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}
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}
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status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT);
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/* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */
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switch (cuda_state) {
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case idle:
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/* CUDA has sent us the first byte of data - unsolicited */
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if (status != TREQ)
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printk("cuda: state=idle, status=%x\n", status);
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(void)in_8(&via[SR]);
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out_8(&via[B], in_8(&via[B]) & ~TIP);
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cuda_state = reading;
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reply_ptr = cuda_rbuf;
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reading_reply = 0;
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break;
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case awaiting_reply:
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/* CUDA has sent us the first byte of data of a reply */
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if (status != TREQ)
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printk("cuda: state=awaiting_reply, status=%x\n", status);
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(void)in_8(&via[SR]);
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out_8(&via[B], in_8(&via[B]) & ~TIP);
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cuda_state = reading;
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reply_ptr = current_req->reply;
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reading_reply = 1;
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break;
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case sent_first_byte:
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if (status == TREQ + TIP + SR_OUT) {
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/* collision */
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out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
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(void)in_8(&via[SR]);
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out_8(&via[B], in_8(&via[B]) | TIP | TACK);
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cuda_state = idle;
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} else {
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/* assert status == TIP + SR_OUT */
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if (status != TIP + SR_OUT)
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printk("cuda: state=sent_first_byte status=%x\n", status);
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out_8(&via[SR], current_req->data[1]);
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out_8(&via[B], in_8(&via[B]) ^ TACK);
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data_index = 2;
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cuda_state = sending;
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}
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break;
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case sending:
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req = current_req;
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if (data_index >= req->nbytes) {
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out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT);
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(void)in_8(&via[SR]);
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out_8(&via[B], in_8(&via[B]) | TACK | TIP);
|
|
req->sent = 1;
|
|
if (req->reply_expected) {
|
|
cuda_state = awaiting_reply;
|
|
} else {
|
|
current_req = req->next;
|
|
complete = 1;
|
|
/* not sure about this */
|
|
cuda_state = idle;
|
|
cuda_start();
|
|
}
|
|
} else {
|
|
out_8(&via[SR], req->data[data_index++]);
|
|
out_8(&via[B], in_8(&via[B]) ^ TACK);
|
|
}
|
|
break;
|
|
|
|
case reading:
|
|
*reply_ptr++ = in_8(&via[SR]);
|
|
if (status == TIP) {
|
|
/* that's all folks */
|
|
out_8(&via[B], in_8(&via[B]) | TACK | TIP);
|
|
cuda_state = read_done;
|
|
} else {
|
|
/* assert status == TIP | TREQ */
|
|
if (status != TIP + TREQ)
|
|
printk("cuda: state=reading status=%x\n", status);
|
|
out_8(&via[B], in_8(&via[B]) ^ TACK);
|
|
}
|
|
break;
|
|
|
|
case read_done:
|
|
(void)in_8(&via[SR]);
|
|
if (reading_reply) {
|
|
req = current_req;
|
|
req->reply_len = reply_ptr - req->reply;
|
|
if (req->data[0] == ADB_PACKET) {
|
|
/* Have to adjust the reply from ADB commands */
|
|
if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) {
|
|
/* the 0x2 bit indicates no response */
|
|
req->reply_len = 0;
|
|
} else {
|
|
/* leave just the command and result bytes in the reply */
|
|
req->reply_len -= 2;
|
|
memmove(req->reply, req->reply + 2, req->reply_len);
|
|
}
|
|
}
|
|
current_req = req->next;
|
|
complete = 1;
|
|
} else {
|
|
/* This is tricky. We must break the spinlock to call
|
|
* cuda_input. However, doing so means we might get
|
|
* re-entered from another CPU getting an interrupt
|
|
* or calling cuda_poll(). I ended up using the stack
|
|
* (it's only for 16 bytes) and moving the actual
|
|
* call to cuda_input to outside of the lock.
|
|
*/
|
|
ibuf_len = reply_ptr - cuda_rbuf;
|
|
memcpy(ibuf, cuda_rbuf, ibuf_len);
|
|
}
|
|
if (status == TREQ) {
|
|
out_8(&via[B], in_8(&via[B]) & ~TIP);
|
|
cuda_state = reading;
|
|
reply_ptr = cuda_rbuf;
|
|
reading_reply = 0;
|
|
} else {
|
|
cuda_state = idle;
|
|
cuda_start();
|
|
}
|
|
break;
|
|
|
|
default:
|
|
printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state);
|
|
}
|
|
spin_unlock(&cuda_lock);
|
|
if (complete && req) {
|
|
void (*done)(struct adb_request *) = req->done;
|
|
mb();
|
|
req->complete = 1;
|
|
/* Here, we assume that if the request has a done member, the
|
|
* struct request will survive to setting req->complete to 1
|
|
*/
|
|
if (done)
|
|
(*done)(req);
|
|
}
|
|
if (ibuf_len)
|
|
cuda_input(ibuf, ibuf_len);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static void
|
|
cuda_input(unsigned char *buf, int nb)
|
|
{
|
|
int i;
|
|
|
|
switch (buf[0]) {
|
|
case ADB_PACKET:
|
|
#ifdef CONFIG_XMON
|
|
if (nb == 5 && buf[2] == 0x2c) {
|
|
extern int xmon_wants_key, xmon_adb_keycode;
|
|
if (xmon_wants_key) {
|
|
xmon_adb_keycode = buf[3];
|
|
return;
|
|
}
|
|
}
|
|
#endif /* CONFIG_XMON */
|
|
#ifdef CONFIG_ADB
|
|
adb_input(buf+2, nb-2, buf[1] & 0x40);
|
|
#endif /* CONFIG_ADB */
|
|
break;
|
|
|
|
default:
|
|
printk("data from cuda (%d bytes):", nb);
|
|
for (i = 0; i < nb; ++i)
|
|
printk(" %.2x", buf[i]);
|
|
printk("\n");
|
|
}
|
|
}
|