/*
* IDE host driver for AT91 (SAM9, CAP9, AT572D940HF) Static Memory Controller
* with Compact Flash True IDE logic
*
* Copyright (c) 2008, 2009 Kelvatek Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/ide.h>
#include <linux/platform_device.h>
#include <mach/board.h>
#include <mach/gpio.h>
#include <mach/at91sam9_smc.h>
#define DRV_NAME "at91_ide"
#define perr(fmt, args...) pr_err(DRV_NAME ": " fmt, ##args)
#define pdbg(fmt, args...) pr_debug("%s " fmt, __func__, ##args)
/*
* Access to IDE device is possible through EBI Static Memory Controller
* with Compact Flash logic. For details see EBI and SMC datasheet sections
* of any microcontroller from AT91SAM9 family.
*
* Within SMC chip select address space, lines A[23:21] distinguish Compact
* Flash modes (I/O, common memory, attribute memory, True IDE). IDE modes are:
* 0x00c0000 - True IDE
* 0x00e0000 - Alternate True IDE (Alt Status Register)
*
* On True IDE mode Task File and Data Register are mapped at the same address.
* To distinguish access between these two different bus data width is used:
* 8Bit for Task File, 16Bit for Data I/O.
*
* After initialization we do 8/16 bit flipping (changes in SMC MODE register)
* only inside IDE callback routines which are serialized by IDE layer,
* so no additional locking needed.
*/
#define TASK_FILE 0x00c00000
#define ALT_MODE 0x00e00000
#define REGS_SIZE 8
#define enter_16bit(cs, mode) do { \
mode = at91_sys_read(AT91_SMC_MODE(cs)); \
at91_sys_write(AT91_SMC_MODE(cs), mode | AT91_SMC_DBW_16); \
} while (0)
#define leave_16bit(cs, mode) at91_sys_write(AT91_SMC_MODE(cs), mode);
static void set_smc_timings(const u8 chipselect, const u16 cycle,
const u16 setup, const u16 pulse,
const u16 data_float, int use_iordy)
{
unsigned long mode = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
AT91_SMC_BAT_SELECT;
/* disable or enable waiting for IORDY signal */
if (use_iordy)
mode |= AT91_SMC_EXNWMODE_READY;
/* add data float cycles if needed */
if (data_float)
mode |= AT91_SMC_TDF_(data_float);
at91_sys_write(AT91_SMC_MODE(chipselect), mode);
/* setup timings in SMC */
at91_sys_write(AT91_SMC_SETUP(chipselect), AT91_SMC_NWESETUP_(setup) |
AT91_SMC_NCS_WRSETUP_(0) |
AT91_SMC_NRDSETUP_(setup) |
AT91_SMC_NCS_RDSETUP_(0));
at91_sys_write(AT91_SMC_PULSE(chipselect), AT91_SMC_NWEPULSE_(pulse) |
AT91_SMC_NCS_WRPULSE_(cycle) |
AT91_SMC_NRDPULSE_(pulse) |
AT91_SMC_NCS_RDPULSE_(cycle));
at91_sys_write(AT91_SMC_CYCLE(chipselect), AT91_SMC_NWECYCLE_(cycle) |
AT91_SMC_NRDCYCLE_(cycle));
}
static unsigned int calc_mck_cycles(unsigned int ns, unsigned int mck_hz)
{
u64 tmp = ns;
tmp *= mck_hz;
tmp += 1000*1000*1000 - 1; /* round up */
do_div(tmp, 1000*1000*1000);
return (unsigned int) tmp;
}
static void apply_timings(const u8 chipselect, const u8 pio,
const struct ide_timing *timing, int use_iordy)
{
unsigned int t0, t1, t2, t6z;
unsigned int cycle, setup, pulse, data_float;
unsigned int mck_hz;
struct clk *mck;
/* see table 22 of Compact Flash standard 4.1 for the meaning,
* we do not stretch active (t2) time, so setup (t1) + hold time (th)
* assure at least minimal recovery (t2i) time */
t0 = timing->cyc8b;
t1 = timing->setup;
t2 = timing->act8b;
t6z = (pio < 5) ? 30 : 20;
pdbg("t0=%u t1=%u t2=%u t6z=%u\n", t0, t1, t2, t6z);
mck = clk_get(NULL, "mck");
BUG_ON(IS_ERR(mck));
mck_hz = clk_get_rate(mck);
pdbg("mck_hz=%u\n", mck_hz);
cycle = calc_mck_cycles(t0, mck_hz);
setup = calc_mck_cycles(t1, mck_hz);
pulse = calc_mck_cycles(t2, mck_hz);
data_float = calc_mck_cycles(t6z, mck_hz);
pdbg("cycle=%u setup=%u pulse=%u data_float=%u\n",
cycle, setup, pulse, data_float);
set_smc_timings(chipselect, cycle, setup, pulse, data_float, use_iordy);
}
static void at91_ide_input_data(ide_drive_t *drive, struct ide_cmd *cmd,
void *buf, unsigned int len)
{
ide_hwif_t *hwif = drive->hwif;
struct ide_io_ports *io_ports = &hwif->io_ports;
u8 chipselect = hwif->select_data;
unsigned long mode;
pdbg("cs %u buf %p len %d\n", chipselect, buf, len);
len++;
enter_16bit(chipselect, mode);
readsw((void __iomem *)io_ports->data_addr, buf, len / 2);
leave_16bit(chipselect, mode);
}
static void at91_ide_output_data(ide_drive_t *drive, struct ide_cmd *cmd,
void *buf, unsigned int len)
{
ide_hwif_t *hwif = drive->hwif;
struct ide_io_ports *io_ports = &hwif->io_ports;
u8 chipselect = hwif->select_data;
unsigned long mode;
pdbg("cs %u buf %p len %d\n", chipselect, buf, len);
enter_16bit(chipselect, mode);
writesw((void __iomem *)io_ports->data_addr, buf, len / 2);
leave_16bit(chipselect, mode);
}
static void at91_ide_set_pio_mode(ide_drive_t *drive, const u8 pio)
{
struct ide_timing *timing;
u8 chipselect = drive->hwif->select_data;
int use_iordy = 0;
pdbg("chipselect %u pio %u\n", chipselect, pio);
timing = ide_timing_find_mode(XFER_PIO_0 + pio);
BUG_ON(!timing);
if (ide_pio_need_iordy(drive, pio))
use_iordy = 1;
apply_timings(chipselect, pio, timing, use_iordy);
}
static const struct ide_tp_ops at91_ide_tp_ops = {
.exec_command = ide_exec_command,
.read_status = ide_read_status,
.read_altstatus = ide_read_altstatus,
.write_devctl = ide_write_devctl,
.dev_select = ide_dev_select,
.tf_load = ide_tf_load,
.tf_read = ide_tf_read,
.input_data = at91_ide_input_data,
.output_data = at91_ide_output_data,
};
static const struct ide_port_ops at91_ide_port_ops = {
.set_pio_mode = at91_ide_set_pio_mode,
};
static const struct ide_port_info at91_ide_port_info __initdata = {
.port_ops = &at91_ide_port_ops,
.tp_ops = &at91_ide_tp_ops,
.host_flags = IDE_HFLAG_MMIO | IDE_HFLAG_NO_DMA | IDE_HFLAG_SINGLE |
IDE_HFLAG_NO_IO_32BIT | IDE_HFLAG_UNMASK_IRQS,
.pio_mask = ATA_PIO6,
.chipset = ide_generic,
};
/*
* If interrupt is delivered through GPIO, IRQ are triggered on falling
* and rising edge of signal. Whereas IDE device request interrupt on high
* level (rising edge in our case). This mean we have fake interrupts, so
* we need to check interrupt pin and exit instantly from ISR when line
* is on low level.
*/
irqreturn_t at91_irq_handler(int irq, void *dev_id)
{
int ntries = 8;
int pin_val1, pin_val2;
/* additional deglitch, line can be noisy in badly designed PCB */
do {
pin_val1 = at91_get_gpio_value(irq);
pin_val2 = at91_get_gpio_value(irq);
} while (pin_val1 != pin_val2 && --ntries > 0);
if (pin_val1 == 0 || ntries <= 0)
return IRQ_HANDLED;
return ide_intr(irq, dev_id);
}
static int __init at91_ide_probe(struct platform_device *pdev)
{
int ret;
struct ide_hw hw, *hws[] = { &hw };
struct ide_host *host;
struct resource *res;
unsigned long tf_base = 0, ctl_base = 0;
struct at91_cf_data *board = pdev->dev.platform_data;
if (!board)
return -ENODEV;
if (board->det_pin && at91_get_gpio_value(board->det_pin) != 0) {
perr("no device detected\n");
return -ENODEV;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
perr("can't get memory resource\n");
return -ENODEV;
}
if (!devm_request_mem_region(&pdev->dev, res->start + TASK_FILE,
REGS_SIZE, "ide") ||
!devm_request_mem_region(&pdev->dev, res->start + ALT_MODE,
REGS_SIZE, "alt")) {
perr("memory resources in use\n");
return -EBUSY;
}
pdbg("chipselect %u irq %u res %08lx\n", board->chipselect,
board->irq_pin, (unsigned long) res->start);
tf_base = (unsigned long) devm_ioremap(&pdev->dev, res->start + TASK_FILE,
REGS_SIZE);
ctl_base = (unsigned long) devm_ioremap(&pdev->dev, res->start + ALT_MODE,
REGS_SIZE);
if (!tf_base || !ctl_base) {
perr("can't map memory regions\n");
return -EBUSY;
}
memset(&hw, 0, sizeof(hw));
if (board->flags & AT91_IDE_SWAP_A0_A2) {
/* workaround for stupid hardware bug */
hw.io_ports.data_addr = tf_base + 0;
hw.io_ports.error_addr = tf_base + 4;
hw.io_ports.nsect_addr = tf_base + 2;
hw.io_ports.lbal_addr = tf_base + 6;
hw.io_ports.lbam_addr = tf_base + 1;
hw.io_ports.lbah_addr = tf_base + 5;
hw.io_ports.device_addr = tf_base + 3;
hw.io_ports.command_addr = tf_base + 7;
hw.io_ports.ctl_addr = ctl_base + 3;
} else
ide_std_init_ports(&hw, tf_base, ctl_base + 6);
hw.irq = board->irq_pin;
hw.dev = &pdev->dev;
host = ide_host_alloc(&at91_ide_port_info, hws, 1);
if (!host) {
perr("failed to allocate ide host\n");
return -ENOMEM;
}
/* setup Static Memory Controller - PIO 0 as default */
apply_timings(board->chipselect, 0, ide_timing_find_mode(XFER_PIO_0), 0);
/* with GPIO interrupt we have to do quirks in handler */
if (board->irq_pin >= PIN_BASE)
host->irq_handler = at91_irq_handler;
host->ports[0]->select_data = board->chipselect;
ret = ide_host_register(host, &at91_ide_port_info, hws);
if (ret) {
perr("failed to register ide host\n");
goto err_free_host;
}
platform_set_drvdata(pdev, host);
return 0;
err_free_host:
ide_host_free(host);
return ret;
}
static int __exit at91_ide_remove(struct platform_device *pdev)
{
struct ide_host *host = platform_get_drvdata(pdev);
ide_host_remove(host);
return 0;
}
static struct platform_driver at91_ide_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
.remove = __exit_p(at91_ide_remove),
};
static int __init at91_ide_init(void)
{
return platform_driver_probe(&at91_ide_driver, at91_ide_probe);
}
static void __exit at91_ide_exit(void)
{
platform_driver_unregister(&at91_ide_driver);
}
module_init(at91_ide_init);
module_exit(at91_ide_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Stanislaw Gruszka <stf_xl@wp.pl>");
