// SPDX-License-Identifier: GPL-2.0-only/* mac_esp.c: ESP front-end for Macintosh Quadra systems. * * Adapted from jazz_esp.c and the old mac_esp.c. * * The pseudo DMA algorithm is based on the one used in NetBSD. * See sys/arch/mac68k/obio/esp.c for some background information. * * Copyright (C) 2007-2008 Finn Thain */ #include <linux/kernel.h>#include <linux/types.h>#include <linux/module.h>#include <linux/init.h>#include <linux/interrupt.h>#include <linux/platform_device.h>#include <linux/dma-mapping.h>#include <linux/scatterlist.h>#include <linux/delay.h>#include <linux/io.h>#include <linux/nubus.h>#include <linux/slab.h> #include <asm/irq.h>#include <asm/dma.h>#include <asm/macints.h>#include <asm/macintosh.h>#include <asm/mac_via.h> #include <scsi/scsi_host.h> #include "esp_scsi.h" #define DRV_MODULE_NAME     "mac_esp"#define PFX                 DRV_MODULE_NAME ": "#define DRV_VERSION         "1.000"#define DRV_MODULE_RELDATE  "Sept 15, 2007" #define MAC_ESP_IO_BASE          0x50F00000#define MAC_ESP_REGS_QUADRA      (MAC_ESP_IO_BASE + 0x10000)#define MAC_ESP_REGS_QUADRA2     (MAC_ESP_IO_BASE + 0xF000)#define MAC_ESP_REGS_QUADRA3     (MAC_ESP_IO_BASE + 0x18000)#define MAC_ESP_REGS_SPACING     0x402#define MAC_ESP_PDMA_REG         0xF9800024#define MAC_ESP_PDMA_REG_SPACING 0x4#define MAC_ESP_PDMA_IO_OFFSET   0x100 #define esp_read8(REG)		mac_esp_read8(esp, REG)#define esp_write8(VAL, REG)	mac_esp_write8(esp, VAL, REG) struct mac_esp_priv {	struct esp *esp;	void __iomem *pdma_regs;	void __iomem *pdma_io;};static struct esp *esp_chips[2];static DEFINE_SPINLOCK(esp_chips_lock); #define MAC_ESP_GET_PRIV(esp) ((struct mac_esp_priv *) \			       dev_get_drvdata((esp)->dev)) static inline void mac_esp_write8(struct esp *esp, u8 val, unsigned long reg){	nubus_writeb(val, esp->regs + reg * 16);} static inline u8 mac_esp_read8(struct esp *esp, unsigned long reg){	return nubus_readb(esp->regs + reg * 16);} static void mac_esp_reset_dma(struct esp *esp){	/* Nothing to do. */} static void mac_esp_dma_drain(struct esp *esp){	/* Nothing to do. */} static void mac_esp_dma_invalidate(struct esp *esp){	/* Nothing to do. */} static int mac_esp_dma_error(struct esp *esp){	return esp->send_cmd_error;} static inline int mac_esp_wait_for_empty_fifo(struct esp *esp){	int i = 500000; 	do {		if (!(esp_read8(ESP_FFLAGS) & ESP_FF_FBYTES))			return 0; 		if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)			return 1; 		udelay(2);	} while (--i); 	printk(KERN_ERR PFX "FIFO is not empty (sreg %02x)\n",	       esp_read8(ESP_STATUS));	esp->send_cmd_error = 1;	return 1;} static inline int mac_esp_wait_for_dreq(struct esp *esp){	struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp);	int i = 500000; 	do {		if (mep->pdma_regs == NULL) {			if (via2_scsi_drq_pending())				return 0;		} else {			if (nubus_readl(mep->pdma_regs) & 0x200)				return 0;		} 		if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)			return 1; 		udelay(2);	} while (--i); 	printk(KERN_ERR PFX "PDMA timeout (sreg %02x)\n",	       esp_read8(ESP_STATUS));	esp->send_cmd_error = 1;	return 1;} #define MAC_ESP_PDMA_LOOP(operands) \	asm volatile ( \	     "       tstw %1                   \n" \	     "       jbeq 20f                  \n" \	     "1:     movew " operands "        \n" \	     "2:     movew " operands "        \n" \	     "3:     movew " operands "        \n" \	     "4:     movew " operands "        \n" \	     "5:     movew " operands "        \n" \	     "6:     movew " operands "        \n" \	     "7:     movew " operands "        \n" \	     "8:     movew " operands "        \n" \	     "9:     movew " operands "        \n" \	     "10:    movew " operands "        \n" \	     "11:    movew " operands "        \n" \	     "12:    movew " operands "        \n" \	     "13:    movew " operands "        \n" \	     "14:    movew " operands "        \n" \	     "15:    movew " operands "        \n" \	     "16:    movew " operands "        \n" \	     "       subqw #1,%1               \n" \	     "       jbne 1b                   \n" \	     "20:    tstw %2                   \n" \	     "       jbeq 30f                  \n" \	     "21:    movew " operands "        \n" \	     "       subqw #1,%2               \n" \	     "       jbne 21b                  \n" \	     "30:    tstw %3                   \n" \	     "       jbeq 40f                  \n" \	     "31:    moveb " operands "        \n" \	     "32:    nop                       \n" \	     "40:                              \n" \	     "                                 \n" \	     "       .section __ex_table,\"a\" \n" \	     "       .align  4                 \n" \	     "       .long   1b,40b            \n" \	     "       .long   2b,40b            \n" \	     "       .long   3b,40b            \n" \	     "       .long   4b,40b            \n" \	     "       .long   5b,40b            \n" \	     "       .long   6b,40b            \n" \	     "       .long   7b,40b            \n" \	     "       .long   8b,40b            \n" \	     "       .long   9b,40b            \n" \	     "       .long  10b,40b            \n" \	     "       .long  11b,40b            \n" \	     "       .long  12b,40b            \n" \	     "       .long  13b,40b            \n" \	     "       .long  14b,40b            \n" \	     "       .long  15b,40b            \n" \	     "       .long  16b,40b            \n" \	     "       .long  21b,40b            \n" \	     "       .long  31b,40b            \n" \	     "       .long  32b,40b            \n" \	     "       .previous                 \n" \	     : "+a" (addr), "+r" (count32), "+r" (count2) \	     : "g" (count1), "a" (mep->pdma_io)) static void mac_esp_send_pdma_cmd(struct esp *esp, u32 addr, u32 esp_count,				  u32 dma_count, int write, u8 cmd){	struct mac_esp_priv *mep = MAC_ESP_GET_PRIV(esp); 	esp->send_cmd_error = 0; 	if (!write)		scsi_esp_cmd(esp, ESP_CMD_FLUSH); 	esp_write8((esp_count >> 0) & 0xFF, ESP_TCLOW);	esp_write8((esp_count >> 8) & 0xFF, ESP_TCMED); 	scsi_esp_cmd(esp, cmd); 	do {		unsigned int count32 = esp_count >> 5;		unsigned int count2 = (esp_count & 0x1F) >> 1;		unsigned int count1 = esp_count & 1;		unsigned int start_addr = addr; 		if (mac_esp_wait_for_dreq(esp))			break; 		if (write) {			MAC_ESP_PDMA_LOOP("%4@,%0@+"); 			esp_count -= addr - start_addr;		} else {			unsigned int n; 			MAC_ESP_PDMA_LOOP("%0@+,%4@"); 			if (mac_esp_wait_for_empty_fifo(esp))				break; 			n = (esp_read8(ESP_TCMED) << 8) + esp_read8(ESP_TCLOW);			addr = start_addr + esp_count - n;			esp_count = n;		}	} while (esp_count);} static int mac_esp_irq_pending(struct esp *esp){	if (esp_read8(ESP_STATUS) & ESP_STAT_INTR)		return 1;	return 0;} static u32 mac_esp_dma_length_limit(struct esp *esp, u32 dma_addr, u32 dma_len){	return dma_len > 0xFFFF ? 0xFFFF : dma_len;} static irqreturn_t mac_scsi_esp_intr(int irq, void *dev_id){	int got_intr; 	/*	 * This is an edge triggered IRQ, so we have to be careful to	 * avoid missing a transition when it is shared by two ESP devices.	 */ 	do {		got_intr = 0;		if (esp_chips[0] &&		    (mac_esp_read8(esp_chips[0], ESP_STATUS) & ESP_STAT_INTR)) {			(void)scsi_esp_intr(irq, esp_chips[0]);			got_intr = 1;		}		if (esp_chips[1] &&		    (mac_esp_read8(esp_chips[1], ESP_STATUS) & ESP_STAT_INTR)) {			(void)scsi_esp_intr(irq, esp_chips[1]);			got_intr = 1;		}	} while (got_intr); 	return IRQ_HANDLED;} static struct esp_driver_ops mac_esp_ops = {	.esp_write8       = mac_esp_write8,	.esp_read8        = mac_esp_read8,	.irq_pending      = mac_esp_irq_pending,	.dma_length_limit = mac_esp_dma_length_limit,	.reset_dma        = mac_esp_reset_dma,	.dma_drain        = mac_esp_dma_drain,	.dma_invalidate   = mac_esp_dma_invalidate,	.send_dma_cmd     = mac_esp_send_pdma_cmd,	.dma_error        = mac_esp_dma_error,}; static int esp_mac_probe(struct platform_device *dev){	const struct scsi_host_template *tpnt = &scsi_esp_template;	struct Scsi_Host *host;	struct esp *esp;	int err;	struct mac_esp_priv *mep; 	if (!MACH_IS_MAC)		return -ENODEV; 	if (dev->id > 1)		return -ENODEV; 	host = scsi_host_alloc(tpnt, sizeof(struct esp)); 	err = -ENOMEM;	if (!host)		goto fail; 	host->max_id = 8;	host->dma_boundary = PAGE_SIZE - 1;	esp = shost_priv(host); 	esp->host = host;	esp->dev = &dev->dev; 	esp->command_block = kzalloc(16, GFP_KERNEL);	if (!esp->command_block)		goto fail_unlink;	esp->command_block_dma = (dma_addr_t)esp->command_block; 	esp->scsi_id = 7;	host->this_id = esp->scsi_id;	esp->scsi_id_mask = 1 << esp->scsi_id; 	mep = kzalloc_obj(struct mac_esp_priv);	if (!mep)		goto fail_free_command_block;	mep->esp = esp;	platform_set_drvdata(dev, mep); 	switch (macintosh_config->scsi_type) {	case MAC_SCSI_QUADRA:		esp->cfreq     = 16500000;		esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA;		mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;		mep->pdma_regs = NULL;		break;	case MAC_SCSI_QUADRA2:		esp->cfreq     = 25000000;		esp->regs      = (void __iomem *)(MAC_ESP_REGS_QUADRA2 +				 dev->id * MAC_ESP_REGS_SPACING);		mep->pdma_io   = esp->regs + MAC_ESP_PDMA_IO_OFFSET;		mep->pdma_regs = (void __iomem *)(MAC_ESP_PDMA_REG +				 dev->id * MAC_ESP_PDMA_REG_SPACING);		nubus_writel(0x1d1, mep->pdma_regs);		break;	case MAC_SCSI_QUADRA3:		/* These quadras have a real DMA controller (the PSC) but we		 * don't know how to drive it so we must use PIO instead.		 */		esp->cfreq     = 25000000;		esp->regs      = (void __iomem *)MAC_ESP_REGS_QUADRA3;		mep->pdma_io   = NULL;		mep->pdma_regs = NULL;		break;	}	esp->fifo_reg = esp->regs + ESP_FDATA * 16; 	esp->ops = &mac_esp_ops;	esp->flags = ESP_FLAG_NO_DMA_MAP;	if (mep->pdma_io == NULL) {		printk(KERN_INFO PFX "using PIO for controller %d\n", dev->id);		esp_write8(0, ESP_TCLOW);		esp_write8(0, ESP_TCMED);		esp->flags |= ESP_FLAG_DISABLE_SYNC;		mac_esp_ops.send_dma_cmd = esp_send_pio_cmd;	} else {		printk(KERN_INFO PFX "using PDMA for controller %d\n", dev->id);	} 	host->irq = IRQ_MAC_SCSI; 	/* The request_irq() call is intended to succeed for the first device	 * and fail for the second device.	 */	err = request_irq(host->irq, mac_scsi_esp_intr, 0, "ESP", NULL);	spin_lock(&esp_chips_lock);	if (err < 0 && esp_chips[!dev->id] == NULL) {		spin_unlock(&esp_chips_lock);		goto fail_free_priv;	}	esp_chips[dev->id] = esp;	spin_unlock(&esp_chips_lock); 	err = scsi_esp_register(esp);	if (err)		goto fail_free_irq; 	return 0; fail_free_irq:	spin_lock(&esp_chips_lock);	esp_chips[dev->id] = NULL;	if (esp_chips[!dev->id] == NULL) {		spin_unlock(&esp_chips_lock);		free_irq(host->irq, NULL);	} else		spin_unlock(&esp_chips_lock);fail_free_priv:	kfree(mep);fail_free_command_block:	kfree(esp->command_block);fail_unlink:	scsi_host_put(host);fail:	return err;} static void esp_mac_remove(struct platform_device *dev){	struct mac_esp_priv *mep = platform_get_drvdata(dev);	struct esp *esp = mep->esp;	unsigned int irq = esp->host->irq; 	scsi_esp_unregister(esp); 	spin_lock(&esp_chips_lock);	esp_chips[dev->id] = NULL;	if (esp_chips[!dev->id] == NULL) {		spin_unlock(&esp_chips_lock);		free_irq(irq, NULL);	} else		spin_unlock(&esp_chips_lock); 	kfree(mep); 	kfree(esp->command_block); 	scsi_host_put(esp->host);} static struct platform_driver esp_mac_driver = {	.probe    = esp_mac_probe,	.remove   = esp_mac_remove,	.driver   = {		.name	= DRV_MODULE_NAME,	},};module_platform_driver(esp_mac_driver); MODULE_DESCRIPTION("Mac ESP SCSI driver");MODULE_AUTHOR("Finn Thain");MODULE_LICENSE("GPL v2");MODULE_VERSION(DRV_VERSION);MODULE_ALIAS("platform:" DRV_MODULE_NAME);