isp1301_omap.c

linux-2.6.15.6

/*
 * isp1301_omap - ISP 1301 USB transceiver, talking to OMAP OTG controller
 *
 * Copyright (C) 2004 Texas Instruments
 * Copyright (C) 2004 David Brownell
 *
 * 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.
 */
#undef	DEBUG
#undef	VERBOSE

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/usb_ch9.h>
#include <linux/usb_gadget.h>
#include <linux/usb.h>
#include <linux/usb_otg.h>
#include <linux/i2c.h>
#include <linux/workqueue.h>

#include <asm/irq.h>
#include <asm/arch/usb.h>


#ifndef	DEBUG
#undef	VERBOSE
#endif


#define	DRIVER_VERSION	"24 August 2004"
#define	DRIVER_NAME	(isp1301_driver.name)

MODULE_DESCRIPTION("ISP1301 USB OTG Transceiver Driver");
MODULE_LICENSE("GPL");

struct isp1301 {
	struct otg_transceiver	otg;
	struct i2c_client	client;
	void			(*i2c_release)(struct device *dev);

	int			irq;

	u32			last_otg_ctrl;
	unsigned		working:1;

	struct timer_list	timer;

	/* use keventd context to change the state for us */
	struct work_struct	work;
	
	unsigned long		todo;
#		define WORK_UPDATE_ISP	0	/* update ISP from OTG */
#		define WORK_UPDATE_OTG	1	/* update OTG from ISP */
#		define WORK_HOST_RESUME	4	/* resume host */
#		define WORK_TIMER	6	/* timer fired */
#		define WORK_STOP	7	/* don't resubmit */
};


/* bits in OTG_CTRL_REG */

#define	OTG_XCEIV_OUTPUTS \
	(OTG_ASESSVLD|OTG_BSESSEND|OTG_BSESSVLD|OTG_VBUSVLD|OTG_ID)
#define	OTG_XCEIV_INPUTS \
	(OTG_PULLDOWN|OTG_PULLUP|OTG_DRV_VBUS|OTG_PD_VBUS|OTG_PU_VBUS|OTG_PU_ID)
#define	OTG_CTRL_BITS \
	(OTG_A_BUSREQ|OTG_A_SETB_HNPEN|OTG_B_BUSREQ|OTG_B_HNPEN|OTG_BUSDROP)
	/* and OTG_PULLUP is sometimes written */

#define	OTG_CTRL_MASK	(OTG_DRIVER_SEL| \
	OTG_XCEIV_OUTPUTS|OTG_XCEIV_INPUTS| \
	OTG_CTRL_BITS)


/*-------------------------------------------------------------------------*/

#ifdef	CONFIG_MACH_OMAP_H2

/* board-specific PM hooks */

#include <asm/arch/gpio.h>
#include <asm/arch/mux.h>
#include <asm/mach-types.h>


#if	defined(CONFIG_TPS65010) || defined(CONFIG_TPS65010_MODULE)

#include <asm/arch/tps65010.h>

#else

static inline int tps65010_set_vbus_draw(unsigned mA)
{
	pr_debug("tps65010: draw %d mA (STUB)\n", mA);
	return 0;
}

#endif

static void enable_vbus_draw(struct isp1301 *isp, unsigned mA)
{
	int status = tps65010_set_vbus_draw(mA);
	if (status < 0)
		pr_debug("  VBUS %d mA error %d\n", mA, status);
}

static void enable_vbus_source(struct isp1301 *isp)
{
	/* this board won't supply more than 8mA vbus power.
	 * some boards can switch a 100ma "unit load" (or more).
	 */
}


/* products will deliver OTG messages with LEDs, GUI, etc */
static inline void notresponding(struct isp1301 *isp)
{
	printk(KERN_NOTICE "OTG device not responding.\n");
}


#endif

/*-------------------------------------------------------------------------*/

/* only two addresses possible */
#define	ISP_BASE		0x2c
static unsigned short normal_i2c[] = {
	ISP_BASE, ISP_BASE + 1,
	I2C_CLIENT_END };

I2C_CLIENT_INSMOD;

static struct i2c_driver isp1301_driver;

/* smbus apis are used for portability */

static inline u8
isp1301_get_u8(struct isp1301 *isp, u8 reg)
{
	return i2c_smbus_read_byte_data(&isp->client, reg + 0);
}

static inline int
isp1301_get_u16(struct isp1301 *isp, u8 reg)
{
	return i2c_smbus_read_word_data(&isp->client, reg);
}

static inline int
isp1301_set_bits(struct isp1301 *isp, u8 reg, u8 bits)
{
	return i2c_smbus_write_byte_data(&isp->client, reg + 0, bits);
}

static inline int
isp1301_clear_bits(struct isp1301 *isp, u8 reg, u8 bits)
{
	return i2c_smbus_write_byte_data(&isp->client, reg + 1, bits);
}

/*-------------------------------------------------------------------------*/

/* identification */
#define	ISP1301_VENDOR_ID		0x00	/* u16 read */
#define	ISP1301_PRODUCT_ID		0x02	/* u16 read */
#define	ISP1301_BCD_DEVICE		0x14	/* u16 read */

#define	I2C_VENDOR_ID_PHILIPS		0x04cc
#define	I2C_PRODUCT_ID_PHILIPS_1301	0x1301

/* operational registers */
#define	ISP1301_MODE_CONTROL_1		0x04	/* u8 read, set, +1 clear */
#	define	MC1_SPEED_REG		(1 << 0)
#	define	MC1_SUSPEND_REG		(1 << 1)
#	define	MC1_DAT_SE0		(1 << 2)
#	define	MC1_TRANSPARENT		(1 << 3)
#	define	MC1_BDIS_ACON_EN	(1 << 4)
#	define	MC1_OE_INT_EN		(1 << 5)
#	define	MC1_UART_EN		(1 << 6)
#	define	MC1_MASK		0x7f
#define	ISP1301_MODE_CONTROL_2		0x12	/* u8 read, set, +1 clear */
#	define	MC2_GLOBAL_PWR_DN	(1 << 0)
#	define	MC2_SPD_SUSP_CTRL	(1 << 1)
#	define	MC2_BI_DI		(1 << 2)
#	define	MC2_TRANSP_BDIR0	(1 << 3)
#	define	MC2_TRANSP_BDIR1	(1 << 4)
#	define	MC2_AUDIO_EN		(1 << 5)
#	define	MC2_PSW_EN		(1 << 6)
#	define	MC2_EN2V7		(1 << 7)
#define	ISP1301_OTG_CONTROL_1		0x06	/* u8 read, set, +1 clear */
#	define	OTG1_DP_PULLUP		(1 << 0)
#	define	OTG1_DM_PULLUP		(1 << 1)
#	define	OTG1_DP_PULLDOWN	(1 << 2)
#	define	OTG1_DM_PULLDOWN	(1 << 3)
#	define	OTG1_ID_PULLDOWN	(1 << 4)
#	define	OTG1_VBUS_DRV		(1 << 5)
#	define	OTG1_VBUS_DISCHRG	(1 << 6)
#	define	OTG1_VBUS_CHRG		(1 << 7)
#define	ISP1301_OTG_STATUS		0x10	/* u8 readonly */
#	define	OTG_B_SESS_END		(1 << 6)
#	define	OTG_B_SESS_VLD		(1 << 7)

#define	ISP1301_INTERRUPT_SOURCE	0x08	/* u8 read */
#define	ISP1301_INTERRUPT_LATCH		0x0A	/* u8 read, set, +1 clear */

#define	ISP1301_INTERRUPT_FALLING	0x0C	/* u8 read, set, +1 clear */
#define	ISP1301_INTERRUPT_RISING	0x0E	/* u8 read, set, +1 clear */

/* same bitfields in all interrupt registers */
#	define	INTR_VBUS_VLD		(1 << 0)
#	define	INTR_SESS_VLD		(1 << 1)
#	define	INTR_DP_HI		(1 << 2)
#	define	INTR_ID_GND		(1 << 3)
#	define	INTR_DM_HI		(1 << 4)
#	define	INTR_ID_FLOAT		(1 << 5)
#	define	INTR_BDIS_ACON		(1 << 6)
#	define	INTR_CR_INT		(1 << 7)

/*-------------------------------------------------------------------------*/

static const char *state_string(enum usb_otg_state state)
{
	switch (state) {
	case OTG_STATE_A_IDLE:		return "a_idle";
	case OTG_STATE_A_WAIT_VRISE:	return "a_wait_vrise";
	case OTG_STATE_A_WAIT_BCON:	return "a_wait_bcon";
	case OTG_STATE_A_HOST:		return "a_host";
	case OTG_STATE_A_SUSPEND:	return "a_suspend";
	case OTG_STATE_A_PERIPHERAL:	return "a_peripheral";
	case OTG_STATE_A_WAIT_VFALL:	return "a_wait_vfall";
	case OTG_STATE_A_VBUS_ERR:	return "a_vbus_err";
	case OTG_STATE_B_IDLE:		return "b_idle";
	case OTG_STATE_B_SRP_INIT:	return "b_srp_init";
	case OTG_STATE_B_PERIPHERAL:	return "b_peripheral";
	case OTG_STATE_B_WAIT_ACON:	return "b_wait_acon";
	case OTG_STATE_B_HOST:		return "b_host";
	default:			return "UNDEFINED";
	}
}

static inline const char *state_name(struct isp1301 *isp)
{
	return state_string(isp->otg.state);
}

#ifdef	VERBOSE
#define	dev_vdbg			dev_dbg
#else
#define	dev_vdbg(dev, fmt, arg...)	do{}while(0)
#endif

/*-------------------------------------------------------------------------*/

/* NOTE:  some of this ISP1301 setup is specific to H2 boards;
 * not everything is guarded by board-specific checks, or even using
 * omap_usb_config data to deduce MC1_DAT_SE0 and MC2_BI_DI.
 *
 * ALSO:  this currently doesn't use ISP1301 low-power modes
 * while OTG is running.
 */

static void power_down(struct isp1301 *isp)
{
	isp->otg.state = OTG_STATE_UNDEFINED;

	// isp1301_set_bits(isp, ISP1301_MODE_CONTROL_2, MC2_GLOBAL_PWR_DN);
	isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1, MC1_SUSPEND_REG);

	isp1301_clear_bits(isp, ISP1301_OTG_CONTROL_1, OTG1_ID_PULLDOWN);
	isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_1, MC1_DAT_SE0);
}

static void power_up(struct isp1301 *isp)
{
	// isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_2, MC2_GLOBAL_PWR_DN);
	isp1301_clear_bits(isp, ISP1301_MODE_CONTROL_1, MC1_SUSPEND_REG);
	
	/* do this only when cpu is driving transceiver,
	 * so host won't see a low speed device...
	 */
	isp1301_set_bits(isp, ISP1301_MODE_CONTROL_1, MC1_DAT_SE0);
}

#define	NO_HOST_SUSPEND

static int host_suspend(struct isp1301 *isp)
{
#ifdef	NO_HOST_SUSPEND
	return 0;
#else
	struct device	*dev;

	if (!isp->otg.host)
		return -ENODEV;

	/* Currently ASSUMES only the OTG port matters;
	 * other ports could be active...
	 */
	dev = isp->otg.host->controller;
	return dev->driver->suspend(dev, 3, 0);
#endif
}

static int host_resume(struct isp1301 *isp)
{
#ifdef	NO_HOST_SUSPEND
	return 0;
#else
	struct device	*dev;

	if (!isp->otg.host)
		return -ENODEV;

	dev = isp->otg.host->controller;
	return dev->driver->resume(dev, 0);
#endif
}

static int gadget_suspend(struct isp1301 *isp)
{
	isp->otg.gadget->b_hnp_enable = 0;
	isp->otg.gadget->a_hnp_support = 0;
	isp->otg.gadget->a_alt_hnp_support = 0;
	return usb_gadget_vbus_disconnect(isp->otg.gadget);
}

/*-------------------------------------------------------------------------*/

#define	TIMER_MINUTES	10
#define	TIMER_JIFFIES	(TIMER_MINUTES * 60 * HZ)

/* Almost all our I2C messaging comes from a work queue's task context.
 * NOTE: guaranteeing certain response times might mean we shouldn't
 * share keventd's work queue; a realtime task might be safest.
 */
void
isp1301_defer_work(struct isp1301 *isp, int work)
{
	int status;

	if (isp && !test_and_set_bit(work, &isp->todo)) {
		(void) get_device(&isp->client.dev);
		status = schedule_work(&isp->work);
		if (!status && !isp->working)
			dev_vdbg(&isp->client.dev,
				"work item %d may be lost\n", work);
	}
}

/* called from irq handlers */
static void a_idle(struct isp1301 *isp, const char *tag)
{
	if (isp->otg.state == OTG_STATE_A_IDLE)
		return;

	isp->otg.default_a = 1;
	if (isp->otg.host) {
		isp->otg.host->is_b_host = 0;
		host_suspend(isp);
	}
	if (isp->otg.gadget) {
		isp->otg.gadget->is_a_peripheral = 1;
		gadget_suspend(isp);
	}
	isp->otg.state = OTG_STATE_A_IDLE;
	isp->last_otg_ctrl = OTG_CTRL_REG = OTG_CTRL_REG & OTG_XCEIV_OUTPUTS;
	pr_debug("  --> %s/%s\n", state_name(isp), tag);
}

/* called from irq handlers */
static void b_idle(struct isp1301 *isp, const char *tag)
{
	if (isp->otg.state == OTG_STATE_B_IDLE)
		return;

	isp->otg.default_a = 0;
	if (isp->otg.host) {
		isp->otg.host->is_b_host = 1;
		host_suspend(isp);
	}
	if (isp->otg.gadget) {
		isp->otg.gadget->is_a_peripheral = 0;
		gadget_suspend(isp);
	}
	isp->otg.state = OTG_STATE_B_IDLE;
	isp->last_otg_ctrl = OTG_CTRL_REG = OTG_CTRL_REG & OTG_XCEIV_OUTPUTS;
	pr_debug("  --> %s/%s\n", state_name(isp), tag);
}

static void
dump_regs(struct isp1301 *isp, const char *label)
{
#ifdef	DEBUG
	u8	ctrl = isp1301_get_u8(isp, ISP1301_OTG_CONTROL_1);
	u8	status = isp1301_get_u8(isp, ISP1301_OTG_STATUS);
	u8	src = isp1301_get_u8(isp, ISP1301_INTERRUPT_SOURCE);

	pr_debug("otg: %06x, %s %s, otg/%02x stat/%02x.%02x\n",
		OTG_CTRL_REG, label, state_name(isp),
		ctrl, status, src);
	/* mode control and irq enables don't change much */
#endif
}

/*-------------------------------------------------------------------------*/

#ifdef	CONFIG_USB_OTG

/*
 * The OMAP OTG controller handles most of the OTG state transitions.
 *
 * We translate isp1301 outputs (mostly voltage comparator status) into
 * OTG inputs; OTG outputs (mostly pullup/pulldown controls) and HNP state
 * flags into isp1301 inputs ... and infer state transitions.
 */

#ifdef	VERBOSE

static void check_state(struct isp1301 *isp, const char *tag)
{
	enum usb_otg_state	state = OTG_STATE_UNDEFINED;
	u8			fsm = OTG_TEST_REG & 0x0ff;
	unsigned		extra = 0;

	switch (fsm) {

	/* default-b */
	case 0x0:
		state = OTG_STATE_B_IDLE;
		break;
	case 0x3:
	case 0x7:
		extra = 1;
	case 0x1:
		state = OTG_STATE_B_PERIPHERAL;
		break;
	case 0x11:
		state = OTG_STATE_B_SRP_INIT;
		break;

	/* extra dual-role default-b states */
	case 0x12:
	case 0x13:
	case 0x16:
		extra = 1;
	case 0x17:
		state = OTG_STATE_B_WAIT_ACON;
		break;
	case 0x34:
		state = OTG_STATE_B_HOST;
		break;

	/* default-a */
	case 0x36:
		state = OTG_STATE_A_IDLE;
		break;
	case 0x3c:
		state = OTG_STATE_A_WAIT_VFALL;
		break;
	case 0x7d:
		state = OTG_STATE_A_VBUS_ERR;
		break;
	case 0x9e:
	case 0x9f:
		extra = 1;
	case 0x89:
		state = OTG_STATE_A_PERIPHERAL;
		break;
	case 0xb7:
		state = OTG_STATE_A_WAIT_VRISE;
		break;
	case 0xb8:
		state = OTG_STATE_A_WAIT_BCON;
		break;
	case 0xb9:
		state = OTG_STATE_A_HOST;
		break;
	case 0xba:
		state = OTG_STATE_A_SUSPEND;
		break;
	default:
		break;
	}
	if (isp->otg.state == state && !extra)
		return;
	pr_debug("otg: %s FSM %s/%02x, %s, %06x\n", tag,
		state_string(state), fsm, state_name(isp), OTG_CTRL_REG);
}

#else

static inline void check_state(struct isp1301 *isp, const char *tag) { }

#endif

/* outputs from ISP1301_INTERRUPT_SOURCE */
static void update_otg1(struct isp1301 *isp, u8 int_src)
{
	u32	otg_ctrl;

	otg_ctrl = OTG_CTRL_REG
			& OTG_CTRL_MASK
			& ~OTG_XCEIV_INPUTS
			& ~(OTG_ID|OTG_ASESSVLD|OTG_VBUSVLD);
	if (int_src & INTR_SESS_VLD)
		otg_ctrl |= OTG_ASESSVLD;
	else if (isp->otg.state == OTG_STATE_A_WAIT_VFALL) {
		a_idle(isp, "vfall");
		otg_ctrl &= ~OTG_CTRL_BITS;
	}
	if (int_src & INTR_VBUS_VLD)
		otg_ctrl |= OTG_VBUSVLD;
	if (int_src & INTR_ID_GND) {		/* default-A */
		if (isp->otg.state == OTG_STATE_B_IDLE
				|| isp->otg.state == OTG_STATE_UNDEFINED) {
			a_idle(isp, "init");
			return;
		}
	} else {				/* default-B */
		otg_ctrl |= OTG_ID;
		if (isp->otg.state == OTG_STATE_A_IDLE
				|| isp->otg.state == OTG_STATE_UNDEFINED) {
			b_idle(isp, "init");
			return;
		}
	}
	OTG_CTRL_REG = otg_ctrl;
}

/* outputs from ISP1301_OTG_STATUS */
static void update_otg2(struct isp1301 *isp, u8 otg_status)
{
	u32	otg_ctrl;

	otg_ctrl = OTG_CTRL_REG
			& OTG_CTRL_MASK