AVR32 PATA driver

Updated and simplified driver. Use only register transfer timing for both
data and register transfers. This gives poorer performance in PIO1 and 2,
but should not be a problem in PIO3 and 4, correct me if I'm wrong :)

The driver works very we'll but I still wonder about the interrupts. I have
an interrupt line, that works nicely when POLLING flag is not set. The
problem is the number of interrupts that eat away my CPU cycles.

When using the POLLING flag there seem to be some interrupts that dosen't get
cleared. Furthermore the device dosen't drive INTRQ high, it stays at 2.5 volts
and generates a lot of interrupts due to ripple / noise. What to do?

Signed-off-by: Kristoffer Nyborg Gregertsen <kngregertsen@norway.atmel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 441 insertions, 0 deletions

diff --git a/drivers/ata/pata_at32.c b/drivers/ata/pata_at32.c
new file mode 100644
index 000000000000..bb250a48e27c
--- /dev/null
+++ b/drivers/ata/pata_at32.c
@@ -0,0 +1,441 @@
+/*
+ * AVR32 SMC/CFC PATA Driver
+ *
+ * Copyright (C) 2007 Atmel Norway
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ */
+
+#define DEBUG
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <scsi/scsi_host.h>
+#include <linux/ata.h>
+#include <linux/libata.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <asm/arch/board.h>
+#include <asm/arch/smc.h>
+
+#define DRV_NAME "pata_at32"
+#define DRV_VERSION "0.0.2"
+
+/*
+ * CompactFlash controller memory layout relative to the base address:
+ *
+ *      Attribute memory:  0000 0000 -> 003f ffff
+ *      Common memory:     0040 0000 -> 007f ffff
+ *      I/O memory:        0080 0000 -> 00bf ffff
+ *      True IDE Mode:     00c0 0000 -> 00df ffff
+ *      Alt IDE Mode:      00e0 0000 -> 00ff ffff
+ *
+ * Only True IDE and Alt True IDE mode are needed for this driver.
+ *
+ *      True IDE mode     => CS0 = 0, CS1 = 1 (cmd, error, stat, etc)
+ *      Alt True IDE mode => CS0 = 1, CS1 = 0 (ctl, alt_stat)
+ */
+#define CF_IDE_OFFSET     0x00c00000
+#define CF_ALT_IDE_OFFSET 0x00e00000
+#define CF_RES_SIZE       2048
+
+/*
+ * Define DEBUG_BUS if you are doing debugging of your own EBI -> PATA
+ * adaptor with a logic analyzer or similar.
+ */
+#undef DEBUG_BUS
+
+/*
+ * ATA PIO modes
+ *
+ *      Name    | Mb/s  | Min cycle time | Mask
+ *      --------+-------+----------------+--------
+ *      Mode 0  | 3.3   | 600 ns         | 0x01
+ *      Mode 1  | 5.2   | 383 ns         | 0x03
+ *      Mode 2  | 8.3   | 240 ns         | 0x07
+ *      Mode 3  | 11.1  | 180 ns         | 0x0f
+ *      Mode 4  | 16.7  | 120 ns         | 0x1f
+ */
+#define PIO_MASK (0x1f)
+
+/*
+ * Struct containing private information about device.
+ */
+struct at32_ide_info {
+        unsigned int            irq;
+        struct resource         res_ide;
+        struct resource         res_alt;
+        void __iomem            *ide_addr;
+        void __iomem            *alt_addr;
+        unsigned int            cs;
+        struct smc_config       smc;
+};
+
+/*
+ * Setup SMC for the given ATA timing.
+ */
+static int pata_at32_setup_timing(struct device *dev,
+                                  struct at32_ide_info *info,
+                                  const struct ata_timing *timing)
+{
+        /* These two values are found through testing */
+        const int min_recover = 25;
+        const int ncs_hold    = 15;
+
+        struct smc_config *smc = &info->smc;
+
+        int active;
+        int recover;
+
+        /* Total cycle time */
+        smc->read_cycle = timing->cyc8b;
+
+        /* DIOR <= CFIOR timings */
+        smc->nrd_setup = timing->setup;
+        smc->nrd_pulse = timing->act8b;
+
+        /* Compute recover, extend total cycle if needed */
+        active  = smc->nrd_setup + smc->nrd_pulse;
+        recover = smc->read_cycle - active;
+
+        if (recover < min_recover) {
+                smc->read_cycle = active + min_recover;
+                recover = min_recover;
+        }
+
+        /* (CS0, CS1, DIR, OE) <= (CFCE1, CFCE2, CFRNW, NCSX) timings */
+        smc->ncs_read_setup  = 0;
+        smc->ncs_read_pulse  = active + ncs_hold;
+
+        /* Write timings same as read timings */
+        smc->write_cycle = smc->read_cycle;
+        smc->nwe_setup = smc->nrd_setup;
+        smc->nwe_pulse = smc->nrd_pulse;
+        smc->ncs_write_setup = smc->ncs_read_setup;
+        smc->ncs_write_pulse = smc->ncs_read_pulse;
+
+        /* Do some debugging output */
+        dev_dbg(dev, "SMC: C=%d S=%d P=%d R=%d NCSS=%d NCSP=%d NCSR=%d\n",
+                smc->read_cycle, smc->nrd_setup, smc->nrd_pulse,
+                recover, smc->ncs_read_setup, smc->ncs_read_pulse,
+                smc->read_cycle - smc->ncs_read_pulse);
+
+        /* Finally, configure the SMC */
+        return smc_set_configuration(info->cs, smc);
+}
+
+/*
+ * Procedures for libATA.
+ */
+static void pata_at32_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+        struct ata_timing timing;
+        struct at32_ide_info *info = ap->host->private_data;
+
+        int ret;
+
+        /* Compute ATA timing */
+        ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
+        if (ret) {
+                dev_warn(ap->dev, "Failed to compute ATA timing %d\n", ret);
+                return;
+        }
+
+        /* Setup SMC to ATA timing */
+        ret = pata_at32_setup_timing(ap->dev, info, &timing);
+        if (ret) {
+                dev_warn(ap->dev, "Failed to setup ATA timing %d\n", ret);
+                return;
+        }
+}
+
+static void pata_at32_irq_clear(struct ata_port *ap)
+{
+        /* No DMA controller yet */
+}
+
+static struct scsi_host_template at32_sht = {
+        .module                 = THIS_MODULE,
+        .name                   = DRV_NAME,
+        .ioctl                  = ata_scsi_ioctl,
+        .queuecommand           = ata_scsi_queuecmd,
+        .can_queue              = ATA_DEF_QUEUE,
+        .this_id                = ATA_SHT_THIS_ID,
+        .sg_tablesize           = LIBATA_MAX_PRD,
+        .cmd_per_lun            = ATA_SHT_CMD_PER_LUN,
+        .emulated               = ATA_SHT_EMULATED,
+        .use_clustering         = ATA_SHT_USE_CLUSTERING,
+        .proc_name              = DRV_NAME,
+        .dma_boundary           = ATA_DMA_BOUNDARY,
+        .slave_configure        = ata_scsi_slave_config,
+        .slave_destroy          = ata_scsi_slave_destroy,
+        .bios_param             = ata_std_bios_param,
+};
+
+static struct ata_port_operations at32_port_ops = {
+        .port_disable           = ata_port_disable,
+        .set_piomode            = pata_at32_set_piomode,
+        .tf_load                = ata_tf_load,
+        .tf_read                = ata_tf_read,
+        .exec_command           = ata_exec_command,
+        .check_status           = ata_check_status,
+        .dev_select             = ata_std_dev_select,
+
+        .freeze                 = ata_bmdma_freeze,
+        .thaw                   = ata_bmdma_thaw,
+        .error_handler          = ata_bmdma_error_handler,
+        .post_internal_cmd      = ata_bmdma_post_internal_cmd,
+        .cable_detect           = ata_cable_40wire,
+
+        .qc_prep                = ata_qc_prep,
+        .qc_issue               = ata_qc_issue_prot,
+
+        .data_xfer              = ata_data_xfer,
+
+        .irq_clear              = pata_at32_irq_clear,
+        .irq_on                 = ata_irq_on,
+        .irq_ack                = ata_irq_ack,
+
+        .port_start             = ata_sff_port_start,
+};
+
+static int __init pata_at32_init_one(struct device *dev,
+                                     struct at32_ide_info *info)
+{
+        struct ata_host *host;
+        struct ata_port *ap;
+
+        host = ata_host_alloc(dev, 1);
+        if (!host)
+                return -ENOMEM;
+
+        ap = host->ports[0];
+
+        /* Setup ATA bindings */
+        ap->ops      = &at32_port_ops;
+        ap->pio_mask = PIO_MASK;
+        ap->flags    = ATA_FLAG_MMIO | ATA_FLAG_SLAVE_POSS
+                | ATA_FLAG_PIO_POLLING;
+
+        /*
+         * Since all 8-bit taskfile transfers has to go on the lower
+         * byte of the data bus and there is a bug in the SMC that
+         * makes it impossible to alter the bus width during runtime,
+         * we need to hardwire the address signals as follows:
+         *
+         *      A_IDE(2:0) <= A_EBI(3:1)
+         *
+         * This makes all addresses on the EBI even, thus all data
+         * will be on the lower byte of the data bus.  All addresses
+         * used by libATA need to be altered according to this.
+         */
+        ap->ioaddr.altstatus_addr = info->alt_addr + (0x06 << 1);
+        ap->ioaddr.ctl_addr       = info->alt_addr + (0x06 << 1);
+
+        ap->ioaddr.data_addr      = info->ide_addr + (ATA_REG_DATA << 1);
+        ap->ioaddr.error_addr     = info->ide_addr + (ATA_REG_ERR << 1);
+        ap->ioaddr.feature_addr   = info->ide_addr + (ATA_REG_FEATURE << 1);
+        ap->ioaddr.nsect_addr     = info->ide_addr + (ATA_REG_NSECT << 1);
+        ap->ioaddr.lbal_addr      = info->ide_addr + (ATA_REG_LBAL << 1);
+        ap->ioaddr.lbam_addr      = info->ide_addr + (ATA_REG_LBAM << 1);
+        ap->ioaddr.lbah_addr      = info->ide_addr + (ATA_REG_LBAH << 1);
+        ap->ioaddr.device_addr    = info->ide_addr + (ATA_REG_DEVICE << 1);
+        ap->ioaddr.status_addr    = info->ide_addr + (ATA_REG_STATUS << 1);
+        ap->ioaddr.command_addr   = info->ide_addr + (ATA_REG_CMD << 1);
+
+        /* Set info as private data of ATA host */
+        host->private_data = info;
+
+        /* Register ATA device and return */
+        return ata_host_activate(host, info->irq, ata_interrupt,
+                                 IRQF_SHARED | IRQF_TRIGGER_RISING,
+                                 &at32_sht);
+}
+
+/*
+ * This function may come in handy for people analyzing their own
+ * EBI -> PATA adaptors.
+ */
+#ifdef DEBUG_BUS
+
+static void __init pata_at32_debug_bus(struct device *dev,
+                                       struct at32_ide_info *info)
+{
+        const int d1 = 0xff;
+        const int d2 = 0x00;
+
+        int i;
+
+        /* Write 8-bit values (registers) */
+        iowrite8(d1, info->alt_addr + (0x06 << 1));
+        iowrite8(d2, info->alt_addr + (0x06 << 1));
+
+        for (i = 0; i < 8; i++) {
+                iowrite8(d1, info->ide_addr + (i << 1));
+                iowrite8(d2, info->ide_addr + (i << 1));
+        }
+
+        /* Write 16 bit values (data) */
+        iowrite16(d1,      info->ide_addr);
+        iowrite16(d1 << 8, info->ide_addr);
+
+        iowrite16(d1,      info->ide_addr);
+        iowrite16(d1 << 8, info->ide_addr);
+}
+
+#endif
+
+static int __init pata_at32_probe(struct platform_device *pdev)
+{
+        const struct ata_timing initial_timing =
+                {XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0};
+
+        struct device            *dev = &pdev->dev;
+        struct at32_ide_info     *info;
+        struct ide_platform_data *board = pdev->dev.platform_data;
+        struct resource          *res;
+
+        int irq;
+        int ret;
+
+        if (!board)
+                return -ENXIO;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res)
+                return -ENXIO;
+
+        /* Retrive IRQ */
+        irq = platform_get_irq(pdev, 0);
+        if (irq < 0)
+                return irq;
+
+        /* Setup struct containing private infomation */
+        info = kzalloc(sizeof(struct at32_ide_info), GFP_KERNEL);
+        if (!info)
+                return -ENOMEM;
+
+        memset(info, 0, sizeof(struct at32_ide_info));
+
+        info->irq = irq;
+        info->cs  = board->cs;
+
+        /* Request memory resources */
+        info->res_ide.start = res->start + CF_IDE_OFFSET;
+        info->res_ide.end   = info->res_ide.start + CF_RES_SIZE - 1;
+        info->res_ide.name  = "ide";
+        info->res_ide.flags = IORESOURCE_MEM;
+
+        ret = request_resource(res, &info->res_ide);
+        if (ret)
+                goto err_req_res_ide;
+
+        info->res_alt.start = res->start + CF_ALT_IDE_OFFSET;
+        info->res_alt.end   = info->res_alt.start + CF_RES_SIZE - 1;
+        info->res_alt.name  = "alt";
+        info->res_alt.flags = IORESOURCE_MEM;
+
+        ret = request_resource(res, &info->res_alt);
+        if (ret)
+                goto err_req_res_alt;
+
+        /* Setup non-timing elements of SMC */
+        info->smc.bus_width      = 2; /* 16 bit data bus */
+        info->smc.nrd_controlled = 1; /* Sample data on rising edge of NRD */
+        info->smc.nwe_controlled = 0; /* Drive data on falling edge of NCS */
+        info->smc.nwait_mode     = 3; /* NWAIT is in READY mode */
+        info->smc.byte_write     = 0; /* Byte select access type */
+        info->smc.tdf_mode       = 0; /* TDF optimization disabled */
+        info->smc.tdf_cycles     = 0; /* No TDF wait cycles */
+
+        /* Setup ATA timing */
+        ret = pata_at32_setup_timing(dev, info, &initial_timing);
+        if (ret)
+                goto err_setup_timing;
+
+        /* Setup ATA addresses */
+        ret = -ENOMEM;
+        info->ide_addr = devm_ioremap(dev, info->res_ide.start, 16);
+        info->alt_addr = devm_ioremap(dev, info->res_alt.start, 16);
+        if (!info->ide_addr || !info->alt_addr)
+                goto err_ioremap;
+
+#ifdef DEBUG_BUS
+        pata_at32_debug_bus(dev, info);
+#endif
+
+        /* Register ATA device */
+        ret = pata_at32_init_one(dev, info);
+        if (ret)
+                goto err_ata_device;
+
+        return 0;
+
+ err_ata_device:
+ err_ioremap:
+ err_setup_timing:
+        release_resource(&info->res_alt);
+ err_req_res_alt:
+        release_resource(&info->res_ide);
+ err_req_res_ide:
+        kfree(info);
+
+        return ret;
+}
+
+static int __exit pata_at32_remove(struct platform_device *pdev)
+{
+        struct ata_host *host = platform_get_drvdata(pdev);
+        struct at32_ide_info *info;
+
+        if (!host)
+                return 0;
+
+        info = host->private_data;
+        ata_host_detach(host);
+
+        if (!info)
+                return 0;
+
+        release_resource(&info->res_ide);
+        release_resource(&info->res_alt);
+
+        kfree(info);
+
+        return 0;
+}
+
+static struct platform_driver pata_at32_driver = {
+        .remove        = __exit_p(pata_at32_remove),
+        .driver        = {
+                .name  = "at32_ide",
+                .owner = THIS_MODULE,
+        },
+};
+
+static int __init pata_at32_init(void)
+{
+        return platform_driver_probe(&pata_at32_driver, pata_at32_probe);
+}
+
+static void __exit pata_at32_exit(void)
+{
+        platform_driver_unregister(&pata_at32_driver);
+}
+
+module_init(pata_at32_init);
+module_exit(pata_at32_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("AVR32 SMC/CFC PATA Driver");
+MODULE_AUTHOR("Kristoffer Nyborg Gregertsen <kngregertsen@norway.atmel.com>");
+MODULE_VERSION(DRV_VERSION);