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linux/drivers/ata/pata_at91.c
Alexandre Belloni 5a90f8d3b1 ata: at91: use syscon to configure the smc 
Use syscon/regmap to configure the smc. This allows to avoid using
at91sam9_smc.h and to compile the driver in a multiplatform configuration.

The driver will still not probe until the proper DT bindings are added. That
binding will include an atmel,smc property that is a phandle to the SMC the CF
controller is connected to.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2015-05-20 16:36:50 +02:00

507 lines
13 KiB
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/*
* PATA driver for AT91SAM9260 Static Memory Controller
* with CompactFlash interface in True IDE mode
*
* Copyright (C) 2009 Matyukevich Sergey
* 2011 Igor Plyatov
*
* Based on:
* * generic platform driver by Paul Mundt: drivers/ata/pata_platform.c
* * pata_at32 driver by Kristoffer Nyborg Gregertsen
* * at91_ide driver by Stanislaw Gruszka
*
* 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.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/gfp.h>
#include <scsi/scsi_host.h>
#include <linux/ata.h>
#include <linux/clk.h>
#include <linux/libata.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/atmel-smc.h>
#include <linux/platform_device.h>
#include <linux/ata_platform.h>
#include <linux/platform_data/atmel.h>
#include <linux/regmap.h>
#include <asm/gpio.h>
#define DRV_NAME "pata_at91"
#define DRV_VERSION "0.3"
#define CF_IDE_OFFSET 0x00c00000
#define CF_ALT_IDE_OFFSET 0x00e00000
#define CF_IDE_RES_SIZE 0x08
#define CS_PULSE_MAXIMUM 319
#define ER_SMC_CALC 1
#define ER_SMC_RECALC 2
struct at91_ide_info {
unsigned long mode;
unsigned int cs;
struct clk *mck;
void __iomem *ide_addr;
void __iomem *alt_addr;
};
/**
* struct smc_range - range of valid values for SMC register.
*/
struct smc_range {
int min;
int max;
};
struct regmap *smc;
struct at91sam9_smc_generic_fields {
struct regmap_field *setup;
struct regmap_field *pulse;
struct regmap_field *cycle;
struct regmap_field *mode;
} fields;
/**
* adjust_smc_value - adjust value for one of SMC registers.
* @value: adjusted value
* @range: array of SMC ranges with valid values
* @size: SMC ranges array size
*
* This returns the difference between input and output value or negative
* in case of invalid input value.
* If negative returned, then output value = maximal possible from ranges.
*/
static int adjust_smc_value(int *value, struct smc_range *range, int size)
{
int maximum = (range + size - 1)->max;
int remainder;
do {
if (*value < range->min) {
remainder = range->min - *value;
*value = range->min; /* nearest valid value */
return remainder;
} else if ((range->min <= *value) && (*value <= range->max))
return 0;
range++;
} while (--size);
*value = maximum;
return -1; /* invalid value */
}
/**
* calc_smc_vals - calculate SMC register values
* @dev: ATA device
* @setup: SMC_SETUP register value
* @pulse: SMC_PULSE register value
* @cycle: SMC_CYCLE register value
*
* This returns negative in case of invalid values for SMC registers:
* -ER_SMC_RECALC - recalculation required for SMC values,
* -ER_SMC_CALC - calculation failed (invalid input values).
*
* SMC use special coding scheme, see "Coding and Range of Timing
* Parameters" table from AT91SAM9 datasheets.
*
* SMC_SETUP = 128*setup[5] + setup[4:0]
* SMC_PULSE = 256*pulse[6] + pulse[5:0]
* SMC_CYCLE = 256*cycle[8:7] + cycle[6:0]
*/
static int calc_smc_vals(struct device *dev,
int *setup, int *pulse, int *cycle, int *cs_pulse)
{
int ret_val;
int err = 0;
struct smc_range range_setup[] = { /* SMC_SETUP valid values */
{.min = 0, .max = 31}, /* first range */
{.min = 128, .max = 159} /* second range */
};
struct smc_range range_pulse[] = { /* SMC_PULSE valid values */
{.min = 0, .max = 63}, /* first range */
{.min = 256, .max = 319} /* second range */
};
struct smc_range range_cycle[] = { /* SMC_CYCLE valid values */
{.min = 0, .max = 127}, /* first range */
{.min = 256, .max = 383}, /* second range */
{.min = 512, .max = 639}, /* third range */
{.min = 768, .max = 895} /* fourth range */
};
ret_val = adjust_smc_value(setup, range_setup, ARRAY_SIZE(range_setup));
if (ret_val < 0)
dev_warn(dev, "maximal SMC Setup value\n");
else
*cycle += ret_val;
ret_val = adjust_smc_value(pulse, range_pulse, ARRAY_SIZE(range_pulse));
if (ret_val < 0)
dev_warn(dev, "maximal SMC Pulse value\n");
else
*cycle += ret_val;
ret_val = adjust_smc_value(cycle, range_cycle, ARRAY_SIZE(range_cycle));
if (ret_val < 0)
dev_warn(dev, "maximal SMC Cycle value\n");
*cs_pulse = *cycle;
if (*cs_pulse > CS_PULSE_MAXIMUM) {
dev_err(dev, "unable to calculate valid SMC settings\n");
return -ER_SMC_CALC;
}
ret_val = adjust_smc_value(cs_pulse, range_pulse,
ARRAY_SIZE(range_pulse));
if (ret_val < 0) {
dev_warn(dev, "maximal SMC CS Pulse value\n");
} else if (ret_val != 0) {
*cycle = *cs_pulse;
dev_warn(dev, "SMC Cycle extended\n");
err = -ER_SMC_RECALC;
}
return err;
}
/**
* to_smc_format - convert values into SMC format
* @setup: SETUP value of SMC Setup Register
* @pulse: PULSE value of SMC Pulse Register
* @cycle: CYCLE value of SMC Cycle Register
* @cs_pulse: NCS_PULSE value of SMC Pulse Register
*/
static void to_smc_format(int *setup, int *pulse, int *cycle, int *cs_pulse)
{
*setup = (*setup & 0x1f) | ((*setup & 0x80) >> 2);
*pulse = (*pulse & 0x3f) | ((*pulse & 0x100) >> 2);
*cycle = (*cycle & 0x7f) | ((*cycle & 0x300) >> 1);
*cs_pulse = (*cs_pulse & 0x3f) | ((*cs_pulse & 0x100) >> 2);
}
static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
{
unsigned long mul;
/*
* cycles = x [nsec] * f [Hz] / 10^9 [ns in sec] =
* x * (f / 1_000_000_000) =
* x * ((f * 65536) / 1_000_000_000) / 65536 =
* x * (((f / 10_000) * 65536) / 100_000) / 65536 =
*/
mul = (mck_hz / 10000) << 16;
mul /= 100000;
return (ns * mul + 65536) >> 16; /* rounding */
}
/**
* set_smc_timing - SMC timings setup.
* @dev: device
* @info: AT91 IDE info
* @ata: ATA timings
*
* Its assumed that write timings are same as read timings,
* cs_setup = 0 and cs_pulse = cycle.
*/
static void set_smc_timing(struct device *dev, struct ata_device *adev,
struct at91_ide_info *info, const struct ata_timing *ata)
{
int ret = 0;
int use_iordy;
unsigned int t6z; /* data tristate time in ns */
unsigned int cycle; /* SMC Cycle width in MCK ticks */
unsigned int setup; /* SMC Setup width in MCK ticks */
unsigned int pulse; /* CFIOR and CFIOW pulse width in MCK ticks */
unsigned int cs_pulse; /* CS4 or CS5 pulse width in MCK ticks*/
unsigned int tdf_cycles; /* SMC TDF MCK ticks */
unsigned long mck_hz; /* MCK frequency in Hz */
t6z = (ata->mode < XFER_PIO_5) ? 30 : 20;
mck_hz = clk_get_rate(info->mck);
cycle = calc_mck_cycles(ata->cyc8b, mck_hz);
setup = calc_mck_cycles(ata->setup, mck_hz);
pulse = calc_mck_cycles(ata->act8b, mck_hz);
tdf_cycles = calc_mck_cycles(t6z, mck_hz);
do {
ret = calc_smc_vals(dev, &setup, &pulse, &cycle, &cs_pulse);
} while (ret == -ER_SMC_RECALC);
if (ret == -ER_SMC_CALC)
dev_err(dev, "Interface may not operate correctly\n");
dev_dbg(dev, "SMC Setup=%u, Pulse=%u, Cycle=%u, CS Pulse=%u\n",
setup, pulse, cycle, cs_pulse);
to_smc_format(&setup, &pulse, &cycle, &cs_pulse);
/* disable or enable waiting for IORDY signal */
use_iordy = ata_pio_need_iordy(adev);
if (use_iordy)
info->mode |= AT91_SMC_EXNWMODE_READY;
if (tdf_cycles > 15) {
tdf_cycles = 15;
dev_warn(dev, "maximal SMC TDF Cycles value\n");
}
dev_dbg(dev, "Use IORDY=%u, TDF Cycles=%u\n", use_iordy, tdf_cycles);
regmap_fields_write(fields.setup, info->cs,
AT91SAM9_SMC_NRDSETUP(setup) |
AT91SAM9_SMC_NWESETUP(setup) |
AT91SAM9_SMC_NCS_NRDSETUP(0) |
AT91SAM9_SMC_NCS_WRSETUP(0));
regmap_fields_write(fields.pulse, info->cs,
AT91SAM9_SMC_NRDPULSE(pulse) |
AT91SAM9_SMC_NWEPULSE(pulse) |
AT91SAM9_SMC_NCS_NRDPULSE(cs_pulse) |
AT91SAM9_SMC_NCS_WRPULSE(cs_pulse));
regmap_fields_write(fields.cycle, info->cs,
AT91SAM9_SMC_NRDCYCLE(cycle) |
AT91SAM9_SMC_NWECYCLE(cycle));
regmap_fields_write(fields.mode, info->cs, info->mode |
AT91_SMC_TDF_(tdf_cycles));
}
static void pata_at91_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
struct at91_ide_info *info = ap->host->private_data;
struct ata_timing timing;
int ret;
/* Compute ATA timing and set it to SMC */
ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
if (ret) {
dev_warn(ap->dev, "Failed to compute ATA timing %d, "
"set PIO_0 timing\n", ret);
timing = *ata_timing_find_mode(XFER_PIO_0);
}
set_smc_timing(ap->dev, adev, info, &timing);
}
static unsigned int pata_at91_data_xfer_noirq(struct ata_device *dev,
unsigned char *buf, unsigned int buflen, int rw)
{
struct at91_ide_info *info = dev->link->ap->host->private_data;
unsigned int consumed;
unsigned int mode;
unsigned long flags;
local_irq_save(flags);
regmap_fields_read(fields.mode, info->cs, &mode);
/* set 16bit mode before writing data */
regmap_fields_write(fields.mode, info->cs, (mode & ~AT91_SMC_DBW) |
AT91_SMC_DBW_16);
consumed = ata_sff_data_xfer(dev, buf, buflen, rw);
/* restore 8bit mode after data is written */
regmap_fields_write(fields.mode, info->cs, (mode & ~AT91_SMC_DBW) |
AT91_SMC_DBW_8);
local_irq_restore(flags);
return consumed;
}
static struct scsi_host_template pata_at91_sht = {
ATA_PIO_SHT(DRV_NAME),
};
static struct ata_port_operations pata_at91_port_ops = {
.inherits = &ata_sff_port_ops,
.sff_data_xfer = pata_at91_data_xfer_noirq,
.set_piomode = pata_at91_set_piomode,
.cable_detect = ata_cable_40wire,
};
static int at91sam9_smc_fields_init(struct device *dev)
{
struct reg_field field = REG_FIELD(0, 0, 31);
field.id_size = 8;
field.id_offset = AT91SAM9_SMC_GENERIC_BLK_SZ;
field.reg = AT91SAM9_SMC_SETUP(AT91SAM9_SMC_GENERIC);
fields.setup = devm_regmap_field_alloc(dev, smc, field);
if (IS_ERR(fields.setup))
return PTR_ERR(fields.setup);
field.reg = AT91SAM9_SMC_PULSE(AT91SAM9_SMC_GENERIC);
fields.pulse = devm_regmap_field_alloc(dev, smc, field);
if (IS_ERR(fields.pulse))
return PTR_ERR(fields.pulse);
field.reg = AT91SAM9_SMC_CYCLE(AT91SAM9_SMC_GENERIC);
fields.cycle = devm_regmap_field_alloc(dev, smc, field);
if (IS_ERR(fields.cycle))
return PTR_ERR(fields.cycle);
field.reg = AT91SAM9_SMC_MODE(AT91SAM9_SMC_GENERIC);
fields.mode = devm_regmap_field_alloc(dev, smc, field);
if (IS_ERR(fields.mode))
return PTR_ERR(fields.mode);
return 0;
}
static int pata_at91_probe(struct platform_device *pdev)
{
struct at91_cf_data *board = dev_get_platdata(&pdev->dev);
struct device *dev = &pdev->dev;
struct at91_ide_info *info;
struct resource *mem_res;
struct ata_host *host;
struct ata_port *ap;
int irq_flags = 0;
int irq = 0;
int ret;
/* get platform resources: IO/CTL memories and irq/rst pins */
if (pdev->num_resources != 1) {
dev_err(&pdev->dev, "invalid number of resources\n");
return -EINVAL;
}
mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!mem_res) {
dev_err(dev, "failed to get mem resource\n");
return -EINVAL;
}
irq = board->irq_pin;
smc = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "atmel,smc");
if (IS_ERR(smc))
return PTR_ERR(smc);
ret = at91sam9_smc_fields_init(dev);
if (ret < 0)
return ret;
/* init ata host */
host = ata_host_alloc(dev, 1);
if (!host)
return -ENOMEM;
ap = host->ports[0];
ap->ops = &pata_at91_port_ops;
ap->flags |= ATA_FLAG_SLAVE_POSS;
ap->pio_mask = ATA_PIO4;
if (!gpio_is_valid(irq)) {
ap->flags |= ATA_FLAG_PIO_POLLING;
ata_port_desc(ap, "no IRQ, using PIO polling");
}
info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
if (!info) {
dev_err(dev, "failed to allocate memory for private data\n");
return -ENOMEM;
}
info->mck = clk_get(NULL, "mck");
if (IS_ERR(info->mck)) {
dev_err(dev, "failed to get access to mck clock\n");
return -ENODEV;
}
info->cs = board->chipselect;
info->mode = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
AT91_SMC_EXNWMODE_READY | AT91_SMC_BAT_SELECT |
AT91_SMC_DBW_8 | AT91_SMC_TDF_(0);
info->ide_addr = devm_ioremap(dev,
mem_res->start + CF_IDE_OFFSET, CF_IDE_RES_SIZE);
if (!info->ide_addr) {
dev_err(dev, "failed to map IO base\n");
ret = -ENOMEM;
goto err_put;
}
info->alt_addr = devm_ioremap(dev,
mem_res->start + CF_ALT_IDE_OFFSET, CF_IDE_RES_SIZE);
if (!info->alt_addr) {
dev_err(dev, "failed to map CTL base\n");
ret = -ENOMEM;
goto err_put;
}
ap->ioaddr.cmd_addr = info->ide_addr;
ap->ioaddr.ctl_addr = info->alt_addr + 0x06;
ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
ata_sff_std_ports(&ap->ioaddr);
ata_port_desc(ap, "mmio cmd 0x%llx ctl 0x%llx",
(unsigned long long)mem_res->start + CF_IDE_OFFSET,
(unsigned long long)mem_res->start + CF_ALT_IDE_OFFSET);
host->private_data = info;
ret = ata_host_activate(host, gpio_is_valid(irq) ? gpio_to_irq(irq) : 0,
gpio_is_valid(irq) ? ata_sff_interrupt : NULL,
irq_flags, &pata_at91_sht);
if (ret)
goto err_put;
return 0;
err_put:
clk_put(info->mck);
return ret;
}
static int pata_at91_remove(struct platform_device *pdev)
{
struct ata_host *host = platform_get_drvdata(pdev);
struct at91_ide_info *info;
if (!host)
return 0;
info = host->private_data;
ata_host_detach(host);
if (!info)
return 0;
clk_put(info->mck);
return 0;
}
static struct platform_driver pata_at91_driver = {
.probe = pata_at91_probe,
.remove = pata_at91_remove,
.driver = {
.name = DRV_NAME,
},
};
module_platform_driver(pata_at91_driver);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
MODULE_AUTHOR("Matyukevich Sergey");
MODULE_VERSION(DRV_VERSION);
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