am53c974: add new driver

This patch adds a new implementation for the Tekram DC-390T /
AMD AM53c974 SCSI controller, based on the generic
esp_scsi infrastructure.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 537 insertions, 0 deletions

diff --git a/drivers/scsi/am53c974.c b/drivers/scsi/am53c974.c
new file mode 100644
index 000000000000..a16c9cf0f0a2
--- /dev/null
+++ b/drivers/scsi/am53c974.c
@@ -0,0 +1,537 @@
+/*
+ * AMD am53c974 driver.
+ * Copyright (c) 2014 Hannes Reinecke, SUSE Linux GmbH
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+
+#include <scsi/scsi_host.h>
+
+#include "esp_scsi.h"
+
+#define DRV_MODULE_NAME "am53c974"
+#define DRV_MODULE_VERSION "1.00"
+
+static bool am53c974_debug;
+
+#define esp_dma_log(f, a...)						\
+	do {								\
+		if (am53c974_debug)					\
+			shost_printk(KERN_DEBUG, esp->host, f, ##a);	\
+	} while (0)
+
+#define ESP_DMA_CMD 0x10
+#define ESP_DMA_STC 0x11
+#define ESP_DMA_SPA 0x12
+#define ESP_DMA_WBC 0x13
+#define ESP_DMA_WAC 0x14
+#define ESP_DMA_STATUS 0x15
+#define ESP_DMA_SMDLA 0x16
+#define ESP_DMA_WMAC 0x17
+
+#define ESP_DMA_CMD_IDLE 0x00
+#define ESP_DMA_CMD_BLAST 0x01
+#define ESP_DMA_CMD_ABORT 0x02
+#define ESP_DMA_CMD_START 0x03
+#define ESP_DMA_CMD_MASK  0x03
+#define ESP_DMA_CMD_DIAG 0x04
+#define ESP_DMA_CMD_MDL 0x10
+#define ESP_DMA_CMD_INTE_P 0x20
+#define ESP_DMA_CMD_INTE_D 0x40
+#define ESP_DMA_CMD_DIR 0x80
+
+#define ESP_DMA_STAT_PWDN 0x01
+#define ESP_DMA_STAT_ERROR 0x02
+#define ESP_DMA_STAT_ABORT 0x04
+#define ESP_DMA_STAT_DONE 0x08
+#define ESP_DMA_STAT_SCSIINT 0x10
+#define ESP_DMA_STAT_BCMPLT 0x20
+
+/* EEPROM is accessed with 16-bit values */
+#define DC390_EEPROM_READ 0x80
+#define DC390_EEPROM_LEN 0x40
+
+/*
+ * DC390 EEPROM
+ *
+ * 8 * 4 bytes of per-device options
+ * followed by HBA specific options
+ */
+
+/* Per-device options */
+#define DC390_EE_MODE1 0x00
+#define DC390_EE_SPEED 0x01
+
+/* HBA-specific options */
+#define DC390_EE_ADAPT_SCSI_ID 0x40
+#define DC390_EE_MODE2 0x41
+#define DC390_EE_DELAY 0x42
+#define DC390_EE_TAG_CMD_NUM 0x43
+
+#define DC390_EE_MODE1_PARITY_CHK   0x01
+#define DC390_EE_MODE1_SYNC_NEGO    0x02
+#define DC390_EE_MODE1_EN_DISC      0x04
+#define DC390_EE_MODE1_SEND_START   0x08
+#define DC390_EE_MODE1_TCQ          0x10
+
+#define DC390_EE_MODE2_MORE_2DRV    0x01
+#define DC390_EE_MODE2_GREATER_1G   0x02
+#define DC390_EE_MODE2_RST_SCSI_BUS 0x04
+#define DC390_EE_MODE2_ACTIVE_NEGATION 0x08
+#define DC390_EE_MODE2_NO_SEEK      0x10
+#define DC390_EE_MODE2_LUN_CHECK    0x20
+
+struct pci_esp_priv {
+	struct esp *esp;
+	u8 dma_status;
+};
+
+static void pci_esp_dma_drain(struct esp *esp);
+
+static inline struct pci_esp_priv *pci_esp_get_priv(struct esp *esp)
+{
+	struct pci_dev *pdev = esp->dev;
+
+	return pci_get_drvdata(pdev);
+}
+
+static void pci_esp_write8(struct esp *esp, u8 val, unsigned long reg)
+{
+	iowrite8(val, esp->regs + (reg * 4UL));
+}
+
+static u8 pci_esp_read8(struct esp *esp, unsigned long reg)
+{
+	return ioread8(esp->regs + (reg * 4UL));
+}
+
+static void pci_esp_write32(struct esp *esp, u32 val, unsigned long reg)
+{
+	return iowrite32(val, esp->regs + (reg * 4UL));
+}
+
+static dma_addr_t pci_esp_map_single(struct esp *esp, void *buf,
+				     size_t sz, int dir)
+{
+	return pci_map_single(esp->dev, buf, sz, dir);
+}
+
+static int pci_esp_map_sg(struct esp *esp, struct scatterlist *sg,
+			  int num_sg, int dir)
+{
+	return pci_map_sg(esp->dev, sg, num_sg, dir);
+}
+
+static void pci_esp_unmap_single(struct esp *esp, dma_addr_t addr,
+				 size_t sz, int dir)
+{
+	pci_unmap_single(esp->dev, addr, sz, dir);
+}
+
+static void pci_esp_unmap_sg(struct esp *esp, struct scatterlist *sg,
+			     int num_sg, int dir)
+{
+	pci_unmap_sg(esp->dev, sg, num_sg, dir);
+}
+
+static int pci_esp_irq_pending(struct esp *esp)
+{
+	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
+
+	pep->dma_status = pci_esp_read8(esp, ESP_DMA_STATUS);
+	esp_dma_log("dma intr dreg[%02x]\n", pep->dma_status);
+
+	if (pep->dma_status & (ESP_DMA_STAT_ERROR |
+			       ESP_DMA_STAT_ABORT |
+			       ESP_DMA_STAT_DONE |
+			       ESP_DMA_STAT_SCSIINT))
+		return 1;
+
+	return 0;
+}
+
+static void pci_esp_reset_dma(struct esp *esp)
+{
+	/* Nothing to do ? */
+}
+
+static void pci_esp_dma_drain(struct esp *esp)
+{
+	u8 resid;
+	int lim = 1000;
+
+
+	if ((esp->sreg & ESP_STAT_PMASK) == ESP_DOP ||
+	    (esp->sreg & ESP_STAT_PMASK) == ESP_DIP)
+		/* Data-In or Data-Out, nothing to be done */
+		return;
+
+	while (--lim > 0) {
+		resid = pci_esp_read8(esp, ESP_FFLAGS) & ESP_FF_FBYTES;
+		if (resid <= 1)
+			break;
+		cpu_relax();
+	}
+	if (resid > 1) {
+		/* FIFO not cleared */
+		shost_printk(KERN_INFO, esp->host,
+			     "FIFO not cleared, %d bytes left\n",
+			     resid);
+	}
+
+	/*
+	 * When there is a residual BCMPLT will never be set
+	 * (obviously). But we still have to issue the BLAST
+	 * command, otherwise the data will not being transferred.
+	 * But we'll never know when the BLAST operation is
+	 * finished. So check for some time and give up eventually.
+	 */
+	lim = 1000;
+	pci_esp_write8(esp, ESP_DMA_CMD_DIR | ESP_DMA_CMD_BLAST, ESP_DMA_CMD);
+	while (pci_esp_read8(esp, ESP_DMA_STATUS) & ESP_DMA_STAT_BCMPLT) {
+		if (--lim == 0)
+			break;
+		cpu_relax();
+	}
+	pci_esp_write8(esp, ESP_DMA_CMD_DIR | ESP_DMA_CMD_IDLE, ESP_DMA_CMD);
+	esp_dma_log("DMA blast done (%d tries, %d bytes left)\n", lim, resid);
+}
+
+static void pci_esp_dma_invalidate(struct esp *esp)
+{
+	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
+
+	esp_dma_log("invalidate DMA\n");
+
+	pci_esp_write8(esp, ESP_DMA_CMD_IDLE, ESP_DMA_CMD);
+	pep->dma_status = 0;
+}
+
+static int pci_esp_dma_error(struct esp *esp)
+{
+	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
+
+	if (pep->dma_status & ESP_DMA_STAT_ERROR) {
+		u8 dma_cmd = pci_esp_read8(esp, ESP_DMA_CMD);
+
+		if ((dma_cmd & ESP_DMA_CMD_MASK) == ESP_DMA_CMD_START)
+			pci_esp_write8(esp, ESP_DMA_CMD_ABORT, ESP_DMA_CMD);
+
+		return 1;
+	}
+	if (pep->dma_status & ESP_DMA_STAT_ABORT) {
+		pci_esp_write8(esp, ESP_DMA_CMD_IDLE, ESP_DMA_CMD);
+		pep->dma_status = pci_esp_read8(esp, ESP_DMA_CMD);
+		return 1;
+	}
+	return 0;
+}
+
+static void pci_esp_send_dma_cmd(struct esp *esp, u32 addr, u32 esp_count,
+				 u32 dma_count, int write, u8 cmd)
+{
+	struct pci_esp_priv *pep = pci_esp_get_priv(esp);
+	u32 val = 0;
+
+	BUG_ON(!(cmd & ESP_CMD_DMA));
+
+	pep->dma_status = 0;
+
+	/* Set DMA engine to IDLE */
+	if (write)
+		/* DMA write direction logic is inverted */
+		val |= ESP_DMA_CMD_DIR;
+	pci_esp_write8(esp, ESP_DMA_CMD_IDLE | val, ESP_DMA_CMD);
+
+	pci_esp_write8(esp, (esp_count >> 0) & 0xff, ESP_TCLOW);
+	pci_esp_write8(esp, (esp_count >> 8) & 0xff, ESP_TCMED);
+
+	pci_esp_write32(esp, esp_count, ESP_DMA_STC);
+	pci_esp_write32(esp, addr, ESP_DMA_SPA);
+
+	esp_dma_log("start dma addr[%x] count[%d:%d]\n",
+		    addr, esp_count, dma_count);
+
+	scsi_esp_cmd(esp, cmd);
+	/* Send DMA Start command */
+	pci_esp_write8(esp, ESP_DMA_CMD_START | val, ESP_DMA_CMD);
+}
+
+static const struct esp_driver_ops pci_esp_ops = {
+	.esp_write8	=	pci_esp_write8,
+	.esp_read8	=	pci_esp_read8,
+	.map_single	=	pci_esp_map_single,
+	.map_sg		=	pci_esp_map_sg,
+	.unmap_single	=	pci_esp_unmap_single,
+	.unmap_sg	=	pci_esp_unmap_sg,
+	.irq_pending	=	pci_esp_irq_pending,
+	.reset_dma	=	pci_esp_reset_dma,
+	.dma_drain	=	pci_esp_dma_drain,
+	.dma_invalidate	=	pci_esp_dma_invalidate,
+	.send_dma_cmd	=	pci_esp_send_dma_cmd,
+	.dma_error	=	pci_esp_dma_error,
+};
+
+/*
+ * Read DC-390 eeprom
+ */
+static void dc390_eeprom_prepare_read(struct pci_dev *pdev, u8 cmd)
+{
+	u8 carry_flag = 1, j = 0x80, bval;
+	int i;
+
+	for (i = 0; i < 9; i++) {
+		if (carry_flag) {
+			pci_write_config_byte(pdev, 0x80, 0x40);
+			bval = 0xc0;
+		} else
+			bval = 0x80;
+
+		udelay(160);
+		pci_write_config_byte(pdev, 0x80, bval);
+		udelay(160);
+		pci_write_config_byte(pdev, 0x80, 0);
+		udelay(160);
+
+		carry_flag = (cmd & j) ? 1 : 0;
+		j >>= 1;
+	}
+}
+
+static u16 dc390_eeprom_get_data(struct pci_dev *pdev)
+{
+	int i;
+	u16 wval = 0;
+	u8 bval;
+
+	for (i = 0; i < 16; i++) {
+		wval <<= 1;
+
+		pci_write_config_byte(pdev, 0x80, 0x80);
+		udelay(160);
+		pci_write_config_byte(pdev, 0x80, 0x40);
+		udelay(160);
+		pci_read_config_byte(pdev, 0x00, &bval);
+
+		if (bval == 0x22)
+			wval |= 1;
+	}
+
+	return wval;
+}
+
+static void dc390_read_eeprom(struct pci_dev *pdev, u16 *ptr)
+{
+	u8 cmd = DC390_EEPROM_READ, i;
+
+	for (i = 0; i < DC390_EEPROM_LEN; i++) {
+		pci_write_config_byte(pdev, 0xc0, 0);
+		udelay(160);
+
+		dc390_eeprom_prepare_read(pdev, cmd++);
+		*ptr++ = dc390_eeprom_get_data(pdev);
+
+		pci_write_config_byte(pdev, 0x80, 0);
+		pci_write_config_byte(pdev, 0x80, 0);
+		udelay(160);
+	}
+}
+
+static void dc390_check_eeprom(struct esp *esp)
+{
+	u8 EEbuf[128];
+	u16 *ptr = (u16 *)EEbuf, wval = 0;
+	int i;
+
+	dc390_read_eeprom((struct pci_dev *)esp->dev, ptr);
+
+	for (i = 0; i < DC390_EEPROM_LEN; i++, ptr++)
+		wval += *ptr;
+
+	/* no Tekram EEprom found */
+	if (wval != 0x1234) {
+		struct pci_dev *pdev = esp->dev;
+		dev_printk(KERN_INFO, &pdev->dev,
+			   "No valid Tekram EEprom found\n");
+		return;
+	}
+	esp->scsi_id = EEbuf[DC390_EE_ADAPT_SCSI_ID];
+	esp->num_tags = 2 << EEbuf[DC390_EE_TAG_CMD_NUM];
+}
+
+static int pci_esp_probe_one(struct pci_dev *pdev,
+			      const struct pci_device_id *id)
+{
+	struct scsi_host_template *hostt = &scsi_esp_template;
+	int err = -ENODEV;
+	struct Scsi_Host *shost;
+	struct esp *esp;
+	struct pci_esp_priv *pep;
+
+	if (pci_enable_device(pdev)) {
+		dev_printk(KERN_INFO, &pdev->dev, "cannot enable device\n");
+		return -ENODEV;
+	}
+
+	if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
+		dev_printk(KERN_INFO, &pdev->dev,
+			   "failed to set 32bit DMA mask\n");
+		goto fail_disable_device;
+	}
+
+	shost = scsi_host_alloc(hostt, sizeof(struct esp));
+	if (!shost) {
+		dev_printk(KERN_INFO, &pdev->dev,
+			   "failed to allocate scsi host\n");
+		err = -ENOMEM;
+		goto fail_disable_device;
+	}
+
+	pep = kzalloc(sizeof(struct pci_esp_priv), GFP_KERNEL);
+	if (!pep) {
+		dev_printk(KERN_INFO, &pdev->dev,
+			   "failed to allocate esp_priv\n");
+		err = -ENOMEM;
+		goto fail_host_alloc;
+	}
+
+	esp = shost_priv(shost);
+	esp->host = shost;
+	esp->dev = pdev;
+	esp->ops = &pci_esp_ops;
+	/*
+	 * The am53c974 HBA has a design flaw of generating
+	 * spurious DMA completion interrupts when using
+	 * DMA for command submission.
+	 */
+	esp->flags |= ESP_FLAG_USE_FIFO;
+	pep->esp = esp;
+
+	if (pci_request_regions(pdev, DRV_MODULE_NAME)) {
+		dev_printk(KERN_ERR, &pdev->dev,
+			   "pci memory selection failed\n");
+		goto fail_priv_alloc;
+	}
+
+	esp->regs = pci_iomap(pdev, 0, pci_resource_len(pdev, 0));
+	if (!esp->regs) {
+		dev_printk(KERN_ERR, &pdev->dev, "pci I/O map failed\n");
+		err = -EINVAL;
+		goto fail_release_regions;
+	}
+	esp->dma_regs = esp->regs;
+
+	pci_set_master(pdev);
+
+	esp->command_block = pci_alloc_consistent(pdev, 16,
+						  &esp->command_block_dma);
+	if (!esp->command_block) {
+		dev_printk(KERN_ERR, &pdev->dev,
+			   "failed to allocate command block\n");
+		err = -ENOMEM;
+		goto fail_unmap_regs;
+	}
+
+	err = request_irq(pdev->irq, scsi_esp_intr, IRQF_SHARED,
+			  DRV_MODULE_NAME, esp);
+	if (err < 0) {
+		dev_printk(KERN_ERR, &pdev->dev, "failed to register IRQ\n");
+		goto fail_unmap_command_block;
+	}
+
+	esp->scsi_id = 7;
+	dc390_check_eeprom(esp);
+
+	shost->this_id = esp->scsi_id;
+	shost->max_id = 8;
+	shost->irq = pdev->irq;
+	shost->io_port = pci_resource_start(pdev, 0);
+	shost->n_io_port = pci_resource_len(pdev, 0);
+	shost->unique_id = shost->io_port;
+	esp->scsi_id_mask = (1 << esp->scsi_id);
+	/* Assume 40MHz clock */
+	esp->cfreq = 40000000;
+
+	pci_set_drvdata(pdev, pep);
+
+	err = scsi_esp_register(esp, &pdev->dev);
+	if (err)
+		goto fail_free_irq;
+
+	return 0;
+
+fail_free_irq:
+	free_irq(pdev->irq, esp);
+fail_unmap_command_block:
+	pci_free_consistent(pdev, 16, esp->command_block,
+			    esp->command_block_dma);
+fail_unmap_regs:
+	pci_iounmap(pdev, esp->regs);
+fail_release_regions:
+	pci_release_regions(pdev);
+fail_priv_alloc:
+	kfree(pep);
+fail_host_alloc:
+	scsi_host_put(shost);
+fail_disable_device:
+	pci_disable_device(pdev);
+
+	return err;
+}
+
+static void pci_esp_remove_one(struct pci_dev *pdev)
+{
+	struct pci_esp_priv *pep = pci_get_drvdata(pdev);
+	struct esp *esp = pep->esp;
+
+	scsi_esp_unregister(esp);
+	free_irq(pdev->irq, esp);
+	pci_free_consistent(pdev, 16, esp->command_block,
+			    esp->command_block_dma);
+	pci_iounmap(pdev, esp->regs);
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	kfree(pep);
+
+	scsi_host_put(esp->host);
+}
+
+static struct pci_device_id am53c974_pci_tbl[] = {
+	{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_SCSI,
+		PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, am53c974_pci_tbl);
+
+static struct pci_driver am53c974_driver = {
+	.name           = DRV_MODULE_NAME,
+	.id_table       = am53c974_pci_tbl,
+	.probe          = pci_esp_probe_one,
+	.remove         = pci_esp_remove_one,
+};
+
+static int __init am53c974_module_init(void)
+{
+	return pci_register_driver(&am53c974_driver);
+}
+
+static void __exit am53c974_module_exit(void)
+{
+	pci_unregister_driver(&am53c974_driver);
+}
+
+MODULE_DESCRIPTION("AM53C974 SCSI driver");
+MODULE_AUTHOR("Hannes Reinecke <hare@suse.de>");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_MODULE_VERSION);
+
+module_param(am53c974_debug, bool, 0644);
+MODULE_PARM_DESC(am53c974_debug, "Enable debugging");
+
+module_init(am53c974_module_init);
+module_exit(am53c974_module_exit);