arm/ti/ti_sdhci.c

/*-
 * Copyright (c) 2013 Ian Lepore <ian@freebsd.org>
 * Copyright (c) 2011 Ben Gray <ben.r.gray@gmail.com>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: head/sys/arm/ti/ti_sdhci.c 254559 2013-08-20 12:33:35Z ian $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/gpio.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <sys/taskqueue.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <machine/intr.h>

#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>

#include <dev/mmc/bridge.h>
#include <dev/mmc/mmcreg.h>
#include <dev/mmc/mmcbrvar.h>

#include <dev/sdhci/sdhci.h>
#include "sdhci_if.h"

#include <arm/ti/ti_cpuid.h>
#include <arm/ti/ti_prcm.h>
#include "gpio_if.h"

struct ti_sdhci_softc {
	device_t		dev;
	device_t		gpio_dev;
	struct resource *	mem_res;
	struct resource *	irq_res;
	void *			intr_cookie;
	struct sdhci_slot	slot;
	uint32_t		mmchs_device_id;
	uint32_t		mmchs_reg_off;
	uint32_t		sdhci_reg_off;
	uint32_t		baseclk_hz;
	uint32_t		wp_gpio_pin;
	uint32_t		cmd_and_mode;
	uint32_t		sdhci_clkdiv;
};

/*
 * The MMCHS hardware has a few control and status registers at the beginning of
 * the device's memory map, followed by the standard sdhci register block.
 * Different SoCs have the register blocks at different offsets from the
 * beginning of the device.  Define some constants to map out the registers we
 * access, and the various per-SoC offsets.  The SDHCI_REG_OFFSET is how far
 * beyond the MMCHS block the SDHCI block is found; it's the same on all SoCs.
 */
#define	OMAP3_MMCHS_REG_OFFSET		0x000
#define	OMAP4_MMCHS_REG_OFFSET		0x100
#define	AM335X_MMCHS_REG_OFFSET		0x100
#define	SDHCI_REG_OFFSET		0x100

#define	MMCHS_SYSCONFIG			0x010
#define	  MMCHS_SYSCONFIG_RESET		  (1 << 1)
#define	MMCHS_SYSSTATUS			0x014
#define	MMCHS_CON			0x02C
#define	  MMCHS_CON_DW8			  (1 << 5)
#define	  MMCHS_CON_DVAL_8_4MS		  (3 << 9)

static inline uint32_t
ti_mmchs_read_4(struct ti_sdhci_softc *sc, bus_size_t off)
{

	return (bus_read_4(sc->mem_res, off + sc->mmchs_reg_off));
}

static inline void
ti_mmchs_write_4(struct ti_sdhci_softc *sc, bus_size_t off, uint32_t val)
{

	bus_write_4(sc->mem_res, off + sc->mmchs_reg_off, val);
}

static inline uint32_t
RD4(struct ti_sdhci_softc *sc, bus_size_t off)
{

	return (bus_read_4(sc->mem_res, off + sc->sdhci_reg_off));
}

static inline void
WR4(struct ti_sdhci_softc *sc, bus_size_t off, uint32_t val)
{

	bus_write_4(sc->mem_res, off + sc->sdhci_reg_off, val);
}

static uint8_t
ti_sdhci_read_1(device_t dev, struct sdhci_slot *slot, bus_size_t off)
{
	struct ti_sdhci_softc *sc = device_get_softc(dev);

	return ((RD4(sc, off & ~3) >> (off & 3) * 8) & 0xff);
}

static uint16_t
ti_sdhci_read_2(device_t dev, struct sdhci_slot *slot, bus_size_t off)
{
	struct ti_sdhci_softc *sc = device_get_softc(dev);
	uint32_t clkdiv, val32;

	/*
	 * The MMCHS hardware has a non-standard interpretation of the sdclock
	 * divisor bits.  It uses the same bit positions as SDHCI 3.0 (15..6)
	 * but doesn't split them into low:high fields.  Instead they're a
	 * single number in the range 0..1023 and the number is exactly the
	 * clock divisor (with 0 and 1 both meaning divide by 1).  The SDHCI
	 * driver code expects a v2.0 divisor (value N is power of two in the
	 * range 0..128 and clock is divided by 2N).  The shifting and masking
	 * here extracts the MMCHS representation from the hardware word, cleans
	 * those bits out, applies the 2N adjustment, and plugs that into the
	 * bit positions for the 2.0 divisor in the returned register value. The
	 * ti_sdhci_write_2() routine performs the opposite transformation when
	 * the SDHCI driver writes to the register.
	 */
	if (off == SDHCI_CLOCK_CONTROL) {
		val32 = RD4(sc, SDHCI_CLOCK_CONTROL);
		clkdiv = (val32 >> SDHCI_DIVIDER_HI_SHIFT) & 0xff;
		val32 &= ~(0xff << SDHCI_DIVIDER_HI_SHIFT);
		val32 |= (clkdiv / 2) << SDHCI_DIVIDER_SHIFT;
		return (val32 & 0xffff);
	}

	/*
	 * Standard 32-bit handling of command and transfer mode.
	 */
	if (off == SDHCI_TRANSFER_MODE) {
		return (sc->cmd_and_mode >> 16);
	} else if (off == SDHCI_COMMAND_FLAGS) {
		return (sc->cmd_and_mode & 0x0000ffff);
	}

	return ((RD4(sc, off & ~3) >> (off & 3) * 8) & 0xffff);
}

static uint32_t
ti_sdhci_read_4(device_t dev, struct sdhci_slot *slot, bus_size_t off)
{
	struct ti_sdhci_softc *sc = device_get_softc(dev);

	return (RD4(sc, off));
}

static void
ti_sdhci_read_multi_4(device_t dev, struct sdhci_slot *slot, bus_size_t off,
    uint32_t *data, bus_size_t count)
{
	struct ti_sdhci_softc *sc = device_get_softc(dev);

	bus_read_multi_4(sc->mem_res, off + sc->sdhci_reg_off, data, count);
}

static void
ti_sdhci_write_1(device_t dev, struct sdhci_slot *slot, bus_size_t off,
    uint8_t val)
{
	struct ti_sdhci_softc *sc = device_get_softc(dev);
	uint32_t val32;

	val32 = RD4(sc, off & ~3);
	val32 &= ~(0xff << (off & 3) * 8);
	val32 |= (val << (off & 3) * 8);

	WR4(sc, off & ~3, val32);
}

static void
ti_sdhci_write_2(device_t dev, struct sdhci_slot *slot, bus_size_t off,
    uint16_t val)
{
	struct ti_sdhci_softc *sc = device_get_softc(dev);
	uint32_t clkdiv, val32;

	/*
	 * Translate between the hardware and SDHCI 2.0 representations of the
	 * clock divisor.  See the comments in ti_sdhci_read_2() for details.
	 */
	if (off == SDHCI_CLOCK_CONTROL) {
		clkdiv = (val >> SDHCI_DIVIDER_SHIFT) & SDHCI_DIVIDER_MASK;
		val32 = RD4(sc, SDHCI_CLOCK_CONTROL);
		val32 &= 0xffff0000;
		val32 |= val & ~(SDHCI_DIVIDER_MASK << SDHCI_DIVIDER_SHIFT);
		val32 |= (clkdiv * 2) << SDHCI_DIVIDER_HI_SHIFT;
		WR4(sc, SDHCI_CLOCK_CONTROL, val32);
		return;
	}

	/*
	 * Standard 32-bit handling of command and transfer mode.
	 */
	if (off == SDHCI_TRANSFER_MODE) {
		sc->cmd_and_mode = (sc->cmd_and_mode & 0xffff0000) |
		    ((uint32_t)val & 0x0000ffff);
		return;
	} else if (off == SDHCI_COMMAND_FLAGS) {
		sc->cmd_and_mode = (sc->cmd_and_mode & 0x0000ffff) |
		    ((uint32_t)val << 16);
		WR4(sc, SDHCI_TRANSFER_MODE, sc->cmd_and_mode);
		return;
	}

	val32 = RD4(sc, off & ~3);
	val32 &= ~(0xffff << (off & 3) * 8);
	val32 |= ((val & 0xffff) << (off & 3) * 8);
	WR4(sc, off & ~3, val32);
}

static void
ti_sdhci_write_4(device_t dev, struct sdhci_slot *slot, bus_size_t off,
    uint32_t val)
{
	struct ti_sdhci_softc *sc = device_get_softc(dev);

	WR4(sc, off, val);
}

static void
ti_sdhci_write_multi_4(device_t dev, struct sdhci_slot *slot, bus_size_t off,
    uint32_t *data, bus_size_t count)
{
	struct ti_sdhci_softc *sc = device_get_softc(dev);

	bus_write_multi_4(sc->mem_res, off + sc->sdhci_reg_off, data, count);
}

static void
ti_sdhci_intr(void *arg)
{
	struct ti_sdhci_softc *sc = arg;

	sdhci_generic_intr(&sc->slot);
}

static int
ti_sdhci_update_ios(device_t brdev, device_t reqdev)
{
	struct ti_sdhci_softc *sc = device_get_softc(brdev);
	struct sdhci_slot *slot;
	struct mmc_ios *ios;
	uint32_t val32;

	slot = device_get_ivars(reqdev);
	ios = &slot->host.ios;

	/*
	 * There is an 8-bit-bus bit in the MMCHS control register which, when
	 * set, overrides the 1 vs 4 bit setting in the standard SDHCI
	 * registers.  Set that bit first according to whether an 8-bit bus is
	 * requested, then let the standard driver handle everything else.
	 */
	val32 = ti_mmchs_read_4(sc, MMCHS_CON);
	if (ios->bus_width == bus_width_8)
		ti_mmchs_write_4(sc, MMCHS_CON, val32 | MMCHS_CON_DW8);
	else
		ti_mmchs_write_4(sc, MMCHS_CON, val32 & ~MMCHS_CON_DW8);

	return (sdhci_generic_update_ios(brdev, reqdev));
}

static int
ti_sdhci_get_ro(device_t brdev, device_t reqdev)
{
	struct ti_sdhci_softc *sc = device_get_softc(brdev);
	unsigned int readonly = 0;

	/* If a gpio pin is configured, read it. */
	if (sc->gpio_dev != NULL) {
		GPIO_PIN_GET(sc->gpio_dev, sc->wp_gpio_pin, &readonly);
	}

	return (readonly);
}

static int
ti_sdhci_detach(device_t dev)
{

	return (EBUSY);
}

static void
ti_sdhci_hw_init(device_t dev)
{
	struct ti_sdhci_softc *sc = device_get_softc(dev);
	clk_ident_t clk;
	unsigned long timeout;

	/* Enable the controller and interface/functional clocks */
	clk = MMC0_CLK + sc->mmchs_device_id;
	if (ti_prcm_clk_enable(clk) != 0) {
		device_printf(dev, "Error: failed to enable MMC clock\n");
		return;
	}

	/* Get the frequency of the source clock */
	if (ti_prcm_clk_get_source_freq(clk, &sc->baseclk_hz) != 0) {
		device_printf(dev, "Error: failed to get source clock freq\n");
		return;
	}

	/* Issue a softreset to the controller */
	ti_mmchs_write_4(sc, MMCHS_SYSCONFIG, MMCHS_SYSCONFIG_RESET);
	timeout = 1000;
	while ((ti_mmchs_read_4(sc, MMCHS_SYSSTATUS) & MMCHS_SYSCONFIG_RESET)) {
		if (--timeout == 0) {
			device_printf(dev, "Error: Controller reset operation timed out\n");
			break;
		}
		DELAY(100);
	}

	/* Reset both the command and data state machines */
	ti_sdhci_write_1(dev, NULL, SDHCI_SOFTWARE_RESET, SDHCI_RESET_ALL);
	timeout = 1000;
	while ((ti_sdhci_read_1(dev, NULL, SDHCI_SOFTWARE_RESET) & SDHCI_RESET_ALL)) {
		if (--timeout == 0) {
			device_printf(dev, "Error: Software reset operation timed out\n");
			break;
		}
		DELAY(100);
	}

	/* Set initial host configuration (1-bit, std speed, pwr off). */
	ti_sdhci_write_1(dev, NULL, SDHCI_HOST_CONTROL, 0);
	ti_sdhci_write_1(dev, NULL, SDHCI_POWER_CONTROL, 0);

	/* Set the initial controller configuration. */
	ti_mmchs_write_4(sc, MMCHS_CON, MMCHS_CON_DVAL_8_4MS);
}

static int
ti_sdhci_attach(device_t dev)
{
	struct ti_sdhci_softc *sc = device_get_softc(dev);
	int rid, err;
	pcell_t prop;
	phandle_t node;

	sc->dev = dev;

	/*
	 * Get the MMCHS device id from FDT.  If it's not there use the newbus
	 * unit number (which will work as long as the devices are in order and
	 * none are skipped in the fdt).
	 */
	node = ofw_bus_get_node(dev);
	if ((OF_getprop(node, "mmchs-device-id", &prop, sizeof(prop))) <= 0) {
		sc->mmchs_device_id = device_get_unit(dev);
		device_printf(dev, "missing mmchs-device-id attribute in FDT, "
		    "using unit number (%d)", sc->mmchs_device_id);
	} else
		sc->mmchs_device_id = fdt32_to_cpu(prop);

	/* See if we've got a GPIO-based write detect pin. */
	if ((OF_getprop(node, "mmchs-wp-gpio-pin", &prop, sizeof(prop))) <= 0)
		sc->wp_gpio_pin = 0xffffffff;
	else
		sc->wp_gpio_pin = fdt32_to_cpu(prop);

	if (sc->wp_gpio_pin != 0xffffffff) {
		sc->gpio_dev = devclass_get_device(devclass_find("gpio"), 0);
		if (sc->gpio_dev == NULL)
			device_printf(dev, "Error: No GPIO device, "
			    "Write Protect pin will not function\n");
		else
			GPIO_PIN_SETFLAGS(sc->gpio_dev, sc->wp_gpio_pin,
			                  GPIO_PIN_INPUT);
	}

	/*
	 * Set the offset from the device's memory start to the MMCHS registers.
	 *
	 * XXX A better way to handle this would be to have separate memory
	 * resources for the sdhci registers and the mmchs registers.  That
	 * requires changing everyone's DTS files.
	 */
	if (ti_chip() == CHIP_OMAP_3)
		sc->mmchs_reg_off = OMAP3_MMCHS_REG_OFFSET;
	else if (ti_chip() == CHIP_OMAP_4)
		sc->mmchs_reg_off = OMAP4_MMCHS_REG_OFFSET;
	else if (ti_chip() == CHIP_AM335X)
		sc->mmchs_reg_off = AM335X_MMCHS_REG_OFFSET;
	else
		panic("Unknown OMAP device\n");

	/*
	 * The standard SDHCI registers are at a fixed offset (the same on all
	 * SoCs) beyond the MMCHS registers.
	 */
	sc->sdhci_reg_off = sc->mmchs_reg_off + SDHCI_REG_OFFSET;

	/* Resource setup. */
	rid = 0;
	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
	    RF_ACTIVE);
	if (!sc->mem_res) {
		device_printf(dev, "cannot allocate memory window\n");
		err = ENXIO;
		goto fail;
	}

	rid = 0;
	sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
	    RF_ACTIVE);
	if (!sc->irq_res) {
		device_printf(dev, "cannot allocate interrupt\n");
		err = ENXIO;
		goto fail;
	}

	if (bus_setup_intr(dev, sc->irq_res, INTR_TYPE_BIO | INTR_MPSAFE,
	    NULL, ti_sdhci_intr, sc, &sc->intr_cookie)) {
		device_printf(dev, "cannot setup interrupt handler\n");
		err = ENXIO;
		goto fail;
	}

	/* Initialise the MMCHS hardware. */
	ti_sdhci_hw_init(dev);

	/*
	 * The capabilities register can only express base clock frequencies in
	 * the range of 0-63MHz for a v2.0 controller.  Since our clock runs
	 * faster than that, the hardware sets the frequency to zero in the
	 * register.  When the register contains zero, the sdhci driver expects
	 * slot.max_clk to already have the right value in it.
	 */
	sc->slot.max_clk = sc->baseclk_hz;

	/*
	 * The MMCHS timeout counter is based on the output sdclock.  Tell the
	 * sdhci driver to recalculate the timeout clock whenever the output
	 * sdclock frequency changes.
	 */
	sc->slot.quirks |= SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK;

	/*
	 * The MMCHS hardware shifts the 136-bit response data (in violation of
	 * the spec), so tell the sdhci driver not to do the same in software.
	 */
	sc->slot.quirks |= SDHCI_QUIRK_DONT_SHIFT_RESPONSE;

	/*
	 * DMA is not really broken, I just haven't implemented it yet.
	 */
	sc->slot.quirks |= SDHCI_QUIRK_BROKEN_DMA;

	/* Set up the hardware and go. */
	sdhci_init_slot(dev, &sc->slot, 0);

	/*
	 * The SDHCI controller doesn't realize it, but we support 8-bit even
	 * though we're not a v3.0 controller.  Advertise the ability.
	 */
	sc->slot.host.caps |= MMC_CAP_8_BIT_DATA;

	bus_generic_probe(dev);
	bus_generic_attach(dev);

	sdhci_start_slot(&sc->slot);

	return (0);

fail:
	if (sc->intr_cookie)
		bus_teardown_intr(dev, sc->irq_res, sc->intr_cookie);
	if (sc->irq_res)
		bus_release_resource(dev, SYS_RES_IRQ, 0, sc->irq_res);
	if (sc->mem_res)
		bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->mem_res);

	return (err);
}

static int
ti_sdhci_probe(device_t dev)
{

	if (!ofw_bus_is_compatible(dev, "ti,mmchs")) {
		return (ENXIO);
	}

	device_set_desc(dev, "TI MMCHS (SDHCI 2.0)");

	return (BUS_PROBE_DEFAULT);
}

static device_method_t ti_sdhci_methods[] = {
	/* Device interface */
	DEVMETHOD(device_probe,		ti_sdhci_probe),
	DEVMETHOD(device_attach,	ti_sdhci_attach),
	DEVMETHOD(device_detach,	ti_sdhci_detach),

	/* Bus interface */
	DEVMETHOD(bus_read_ivar,	sdhci_generic_read_ivar),
	DEVMETHOD(bus_write_ivar,	sdhci_generic_write_ivar),
	DEVMETHOD(bus_print_child,	bus_generic_print_child),

	/* MMC bridge interface */
	DEVMETHOD(mmcbr_update_ios,	ti_sdhci_update_ios),
	DEVMETHOD(mmcbr_request,	sdhci_generic_request),
	DEVMETHOD(mmcbr_get_ro,		ti_sdhci_get_ro),
	DEVMETHOD(mmcbr_acquire_host,	sdhci_generic_acquire_host),
	DEVMETHOD(mmcbr_release_host,	sdhci_generic_release_host),

	/* SDHCI registers accessors */
	DEVMETHOD(sdhci_read_1,		ti_sdhci_read_1),
	DEVMETHOD(sdhci_read_2,		ti_sdhci_read_2),
	DEVMETHOD(sdhci_read_4,		ti_sdhci_read_4),
	DEVMETHOD(sdhci_read_multi_4,	ti_sdhci_read_multi_4),
	DEVMETHOD(sdhci_write_1,	ti_sdhci_write_1),
	DEVMETHOD(sdhci_write_2,	ti_sdhci_write_2),
	DEVMETHOD(sdhci_write_4,	ti_sdhci_write_4),
	DEVMETHOD(sdhci_write_multi_4,	ti_sdhci_write_multi_4),

	DEVMETHOD_END
};

static devclass_t ti_sdhci_devclass;

static driver_t ti_sdhci_driver = {
	"sdhci_ti",
	ti_sdhci_methods,
	sizeof(struct ti_sdhci_softc),
};

DRIVER_MODULE(sdhci_ti, simplebus, ti_sdhci_driver, ti_sdhci_devclass, 0, 0);
MODULE_DEPEND(sdhci_ti, sdhci, 1, 1, 1);