diff options
| author | lars <lars@3c298f89-4303-0410-b956-a3cf2f4a3e73> | 2009-05-18 17:55:41 +0000 | 
|---|---|---|
| committer | lars <lars@3c298f89-4303-0410-b956-a3cf2f4a3e73> | 2009-05-18 17:55:41 +0000 | 
| commit | fb189822fcab111e55d1c7e83c482dc2c144500a (patch) | |
| tree | dd10e61f382ace3afbe40af3af8238757cf5e3d0 /target/linux/s3c24xx/files-2.6.30/drivers/power/hdq.c | |
| parent | c5f7c391b56bb88e21895f0fc9310cd0919e8d0c (diff) | |
[s3c24xx] bump to 2.6.30-rc6
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@15918 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'target/linux/s3c24xx/files-2.6.30/drivers/power/hdq.c')
| -rw-r--r-- | target/linux/s3c24xx/files-2.6.30/drivers/power/hdq.c | 515 | 
1 files changed, 515 insertions, 0 deletions
| diff --git a/target/linux/s3c24xx/files-2.6.30/drivers/power/hdq.c b/target/linux/s3c24xx/files-2.6.30/drivers/power/hdq.c new file mode 100644 index 000000000..f03fabfb1 --- /dev/null +++ b/target/linux/s3c24xx/files-2.6.30/drivers/power/hdq.c @@ -0,0 +1,515 @@ +/* + * HDQ generic GPIO bitbang driver using FIQ + * + * (C) 2006-2007 by Openmoko, Inc. + * Author: Andy Green <andy@openmoko.com> + * All rights reserved. + * + * 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/init.h> +#include <linux/delay.h> +#include <linux/platform_device.h> +#include <linux/hdq.h> + +#define HDQ_READ 0 +#define HDQ_WRITE 0x80 + +enum hdq_bitbang_states { +	HDQB_IDLE = 0, +	HDQB_TX_BREAK, +	HDQB_TX_BREAK_RECOVERY, +	HDQB_ADS_CALC, +	HDQB_ADS_LOW, +	HDQB_ADS_HIGH, +	HDQB_WAIT_RX, +	HDQB_DATA_RX_LOW, +	HDQB_DATA_RX_HIGH, +	HDQB_WAIT_TX, +}; + +static struct hdq_priv { +	u8 hdq_probed; /* nonzero after HDQ driver probed */ +	struct mutex hdq_lock; /* if you want to use hdq, you have to take lock */ +	unsigned long hdq_gpio_pin; /* GTA02 = GPD14 which pin to meddle with */ +	u8 hdq_ads; /* b7..b6 = register address, b0 = r/w */ +	u8 hdq_tx_data; /* data to tx for write action */ +	u8 hdq_rx_data; /* data received in read action */ +	u8 hdq_request_ctr; /* incremented by "user" to request a transfer */ +	u8 hdq_transaction_ctr; /* incremented after each transfer */ +	u8 hdq_error; /* 0 = no error */ +	u8 hdq_ctr; +	u8 hdq_ctr2; +	u8 hdq_bit; +	u8 hdq_shifter; +	u8 hdq_tx_data_done; +	enum hdq_bitbang_states hdq_state; +	int reported_error; + +	struct hdq_platform_data *pdata; +} hdq_priv; + + +static void hdq_bad(void) +{ +	if (!hdq_priv.reported_error) +		printk(KERN_ERR "HDQ error: %d\n", hdq_priv.hdq_error); +	hdq_priv.reported_error = 1; +} + +static void hdq_good(void) +{ +	if (hdq_priv.reported_error) +		printk(KERN_INFO "HDQ responds again\n"); +	hdq_priv.reported_error = 0; +} + +int hdq_fiq_handler(void) +{ +	if (!hdq_priv.hdq_probed) +		return 0; + +	switch (hdq_priv.hdq_state) { +	case HDQB_IDLE: +		if (hdq_priv.hdq_request_ctr == hdq_priv.hdq_transaction_ctr) +			break; +		hdq_priv.hdq_ctr = 250 / HDQ_SAMPLE_PERIOD_US; +		hdq_priv.pdata->gpio_set(0); +		hdq_priv.pdata->gpio_dir_out(); +		hdq_priv.hdq_tx_data_done = 0; +		hdq_priv.hdq_state = HDQB_TX_BREAK; +		break; + +	case HDQB_TX_BREAK: /* issue low for > 190us */ +		if (--hdq_priv.hdq_ctr == 0) { +			hdq_priv.hdq_ctr = 60 / HDQ_SAMPLE_PERIOD_US; +			hdq_priv.hdq_state = HDQB_TX_BREAK_RECOVERY; +			hdq_priv.pdata->gpio_set(1); +		} +		break; + +	case HDQB_TX_BREAK_RECOVERY: /* issue low for > 40us */ +		if (--hdq_priv.hdq_ctr) +			break; +		hdq_priv.hdq_shifter = hdq_priv.hdq_ads; +		hdq_priv.hdq_bit = 8; /* 8 bits of ads / rw */ +		hdq_priv.hdq_tx_data_done = 0; /* doing ads */ +		/* fallthru on last one */ +	case HDQB_ADS_CALC: +		if (hdq_priv.hdq_shifter & 1) +			hdq_priv.hdq_ctr = 50 / HDQ_SAMPLE_PERIOD_US; +		else +			hdq_priv.hdq_ctr = 120 / HDQ_SAMPLE_PERIOD_US; +		/* carefully precompute the other phase length */ +		hdq_priv.hdq_ctr2 = (210 - (hdq_priv.hdq_ctr * HDQ_SAMPLE_PERIOD_US)) / +				HDQ_SAMPLE_PERIOD_US; +		hdq_priv.hdq_state = HDQB_ADS_LOW; +		hdq_priv.hdq_shifter >>= 1; +		hdq_priv.hdq_bit--; +		hdq_priv.pdata->gpio_set(0); +		break; + +	case HDQB_ADS_LOW: +		if (--hdq_priv.hdq_ctr) +			break; +		hdq_priv.pdata->gpio_set(1); +		hdq_priv.hdq_state = HDQB_ADS_HIGH; +		break; + +	case HDQB_ADS_HIGH: +		if (--hdq_priv.hdq_ctr2 > 1) /* account for HDQB_ADS_CALC */ +			break; +		if (hdq_priv.hdq_bit) { /* more bits to do */ +			hdq_priv.hdq_state = HDQB_ADS_CALC; +			break; +		} +		/* no more bits, wait it out until hdq_priv.hdq_ctr2 exhausted */ +		if (hdq_priv.hdq_ctr2) +			break; +		/* ok no more bits and very last state */ +		hdq_priv.hdq_ctr = 60 / HDQ_SAMPLE_PERIOD_US; +		/* FIXME 0 = read */ +		if (hdq_priv.hdq_ads & 0x80) { /* write the byte out */ +			 /* set delay before payload */ +			hdq_priv.hdq_ctr = 300 / HDQ_SAMPLE_PERIOD_US; + 			/* already high, no need to write */ +			hdq_priv.hdq_state = HDQB_WAIT_TX; +			break; +		} +		/* read the next byte */ +		hdq_priv.hdq_bit = 8; /* 8 bits of data */ +		hdq_priv.hdq_ctr = 2500 / HDQ_SAMPLE_PERIOD_US; +		hdq_priv.hdq_state = HDQB_WAIT_RX; +		hdq_priv.pdata->gpio_dir_in(); +		break; + +	case HDQB_WAIT_TX: /* issue low for > 40us */ +		if (--hdq_priv.hdq_ctr) +			break; +		if (!hdq_priv.hdq_tx_data_done) { /* was that the data sent? */ +			hdq_priv.hdq_tx_data_done++; +			hdq_priv.hdq_shifter = hdq_priv.hdq_tx_data; +			hdq_priv.hdq_bit = 8; /* 8 bits of data */ +			hdq_priv.hdq_state = HDQB_ADS_CALC; /* start sending */ +			break; +		} +		hdq_priv.hdq_error = 0; +		hdq_priv.hdq_transaction_ctr = hdq_priv.hdq_request_ctr; +		hdq_priv.hdq_state = HDQB_IDLE; /* all tx is done */ +		/* idle in input mode, it's pulled up by 10K */ +		hdq_priv.pdata->gpio_dir_in(); +		break; + +	case HDQB_WAIT_RX: /* wait for battery to talk to us */ +		if (hdq_priv.pdata->gpio_get() == 0) { +			/* it talks to us! */ +			hdq_priv.hdq_ctr2 = 1; +			hdq_priv.hdq_bit = 8; /* 8 bits of data */ +			/* timeout */ +			hdq_priv.hdq_ctr = 500 / HDQ_SAMPLE_PERIOD_US; +			hdq_priv.hdq_state = HDQB_DATA_RX_LOW; +			break; +		} +		if (--hdq_priv.hdq_ctr == 0) { /* timed out, error */ +			hdq_priv.hdq_error = 1; +			hdq_priv.hdq_transaction_ctr = hdq_priv.hdq_request_ctr; +			hdq_priv.hdq_state = HDQB_IDLE; /* abort */ +		} +		break; + +	/* +	 * HDQ basically works by measuring the low time of the bit cell +	 * 32-50us --> '1', 80 - 145us --> '0' +	 */ + +	case HDQB_DATA_RX_LOW: +		if (hdq_priv.pdata->gpio_get()) { +			hdq_priv.hdq_rx_data >>= 1; +			if (hdq_priv.hdq_ctr2 <= (65 / HDQ_SAMPLE_PERIOD_US)) +				hdq_priv.hdq_rx_data |= 0x80; + +			if (--hdq_priv.hdq_bit == 0) { +				hdq_priv.hdq_error = 0; +				hdq_priv.hdq_transaction_ctr = +							hdq_priv.hdq_request_ctr; + +				hdq_priv.hdq_state = HDQB_IDLE; +			} else +				hdq_priv.hdq_state = HDQB_DATA_RX_HIGH; +			/* timeout */ +			hdq_priv.hdq_ctr = 1000 / HDQ_SAMPLE_PERIOD_US; +			hdq_priv.hdq_ctr2 = 1; +			break; +		} +		hdq_priv.hdq_ctr2++; +		if (--hdq_priv.hdq_ctr) +			break; +		 /* timed out, error */ +		hdq_priv.hdq_error = 2; +		hdq_priv.hdq_transaction_ctr = hdq_priv.hdq_request_ctr; +		hdq_priv.hdq_state = HDQB_IDLE; /* abort */ +		break; + +	case HDQB_DATA_RX_HIGH: +		if (!hdq_priv.pdata->gpio_get()) { +			/* it talks to us! */ +			hdq_priv.hdq_ctr2 = 1; +			/* timeout */ +			hdq_priv.hdq_ctr = 400 / HDQ_SAMPLE_PERIOD_US; +			hdq_priv.hdq_state = HDQB_DATA_RX_LOW; +			break; +		} +		if (--hdq_priv.hdq_ctr) +			break; +		/* timed out, error */ +		hdq_priv.hdq_error = 3; +		hdq_priv.hdq_transaction_ctr = hdq_priv.hdq_request_ctr; + +		/* we're in input mode already */ +		hdq_priv.hdq_state = HDQB_IDLE; /* abort */ +		break; +	} + +	/* Are we interested in keeping the FIQ source alive ? */ +	if (hdq_priv.hdq_state != HDQB_IDLE) +		return 1; +	else +		return 0; +} +static int fiq_busy(void) +{ +	int request = (volatile u8)hdq_priv.hdq_request_ctr; +	int transact = (volatile u8)hdq_priv.hdq_transaction_ctr; + + +	return (request != transact); +} + +int hdq_initialized(void) +{ +	return hdq_priv.hdq_probed; +} +EXPORT_SYMBOL_GPL(hdq_initialized); + +int hdq_read(int address) +{ +	int count_sleeps = 5; +	int ret = -ETIME; + +	if (!hdq_priv.hdq_probed) +		return -EINVAL; + +	mutex_lock(&hdq_priv.hdq_lock); + +	hdq_priv.hdq_error = 0; +	hdq_priv.hdq_ads = address | HDQ_READ; +	hdq_priv.hdq_request_ctr++; +	hdq_priv.pdata->kick_fiq(); +	/* +	 * FIQ takes care of it while we block our calling process +	 * But we're not spinning -- other processes run normally while +	 * we wait for the result +	 */ +	while (count_sleeps--) { +		msleep(10); /* valid transaction always completes in < 10ms */ + +		if (fiq_busy()) +			continue; + +		if (hdq_priv.hdq_error) { +			hdq_bad(); +			goto done; /* didn't see a response in good time */ +		} +		hdq_good(); + +		ret = hdq_priv.hdq_rx_data; +		goto done; +	} + +done: +	mutex_unlock(&hdq_priv.hdq_lock); +	return ret; +} +EXPORT_SYMBOL_GPL(hdq_read); + +int hdq_write(int address, u8 data) +{ +	int count_sleeps = 5; +	int ret = -ETIME; + +	if (!hdq_priv.hdq_probed) +		return -EINVAL; + +	mutex_lock(&hdq_priv.hdq_lock); + +	hdq_priv.hdq_error = 0; +	hdq_priv.hdq_ads = address | HDQ_WRITE; +	hdq_priv.hdq_tx_data = data; +	hdq_priv.hdq_request_ctr++; +	hdq_priv.pdata->kick_fiq(); +	/* +	 * FIQ takes care of it while we block our calling process +	 * But we're not spinning -- other processes run normally while +	 * we wait for the result +	 */ +	while (count_sleeps--) { +		msleep(10); /* valid transaction always completes in < 10ms */ + +		if (fiq_busy()) +			continue; /* something bad with FIQ */ + +		if (hdq_priv.hdq_error) { +			hdq_bad(); +			goto done; /* didn't see a response in good time */ +		} +		hdq_good(); + +		ret = 0; +		goto done; +	} + +done: +	mutex_unlock(&hdq_priv.hdq_lock); +	return ret; +} +EXPORT_SYMBOL_GPL(hdq_write); + +/* sysfs */ + +static ssize_t hdq_sysfs_dump(struct device *dev, struct device_attribute *attr, +			 char *buf) +{ +	int n; +	int v; +	u8 u8a[128]; /* whole address space for HDQ */ +	char *end = buf; + +	if (!hdq_priv.hdq_probed) +		return -EINVAL; + +	/* the dump does not take care about 16 bit regs, because at this +	 * bus level we don't know about the chip details +	 */ +	for (n = 0; n < sizeof(u8a); n++) { +		v = hdq_read(n); +		if (v < 0) +			goto bail; +		u8a[n] = v; +	} + +	for (n = 0; n < sizeof(u8a); n += 16) { +		hex_dump_to_buffer(u8a + n, sizeof(u8a), 16, 1, end, 4096, 0); +		end += strlen(end); +		*end++ = '\n'; +		*end = '\0'; +	} +	return (end - buf); + +bail: +	return sprintf(buf, "ERROR %d\n", v); +} + +/* you write by <address> <data>, eg, "34 128" */ + +#define atoi(str) simple_strtoul(((str != NULL) ? str : ""), NULL, 0) + +static ssize_t hdq_sysfs_write(struct device *dev, +			       struct device_attribute *attr, +			       const char *buf, size_t count) +{ +	const char *end = buf + count; +	int address = atoi(buf); + +	if (!hdq_priv.hdq_probed) +		return -EINVAL; + +	while ((buf != end) && (*buf != ' ')) +		buf++; +	if (buf >= end) +		return 0; +	while ((buf < end) && (*buf == ' ')) +		buf++; +	if (buf >= end) +		return 0; + +	hdq_write(address, atoi(buf)); + +	return count; +} + +static DEVICE_ATTR(dump, 0400, hdq_sysfs_dump, NULL); +static DEVICE_ATTR(write, 0600, NULL, hdq_sysfs_write); + +static struct attribute *hdq_sysfs_entries[] = { +	&dev_attr_dump.attr, +	&dev_attr_write.attr, +	NULL +}; + +static struct attribute_group hdq_attr_group = { +	.name	= "hdq", +	.attrs	= hdq_sysfs_entries, +}; + + +#ifdef CONFIG_PM +static int hdq_suspend(struct platform_device *pdev, pm_message_t state) +{ +	/* after 18s of this, the battery monitor will also go to sleep */ +	hdq_priv.pdata->gpio_dir_in(); +	hdq_priv.pdata->disable_fiq(); +	return 0; +} + +static int hdq_resume(struct platform_device *pdev) +{ +	hdq_priv.pdata->gpio_set(1); +	hdq_priv.pdata->gpio_dir_out(); +	hdq_priv.pdata->enable_fiq(); +	return 0; +} +#endif + +static int __init hdq_probe(struct platform_device *pdev) +{ +	struct resource *r = platform_get_resource(pdev, 0, 0); +	int ret; +	struct hdq_platform_data *pdata = pdev->dev.platform_data; + +	if (!r || !pdata) +		return -EINVAL; + +	platform_set_drvdata(pdev, NULL); + +	mutex_init(&hdq_priv.hdq_lock); + +	/* set our HDQ comms pin from the platform data */ +	hdq_priv.hdq_gpio_pin = r->start; +	hdq_priv.pdata = pdata; + +	hdq_priv.pdata->gpio_set(1); +	hdq_priv.pdata->gpio_dir_out(); + +	/* Initialize FIQ */ +	if (hdq_priv.pdata->enable_fiq() < 0) { +		dev_err(&pdev->dev, "Could not enable FIQ source\n"); +		return -EINVAL; +	} + +	ret = sysfs_create_group(&pdev->dev.kobj, &hdq_attr_group); +	if (ret) +		return ret; + +	hdq_priv.hdq_probed = 1; /* we are ready to do stuff now */ + +	/* +	 * if wanted, users can defer registration of devices +	 * that depend on HDQ until after we register, and can use our +	 * device as parent so suspend-resume ordering is correct +	 */ +	if (pdata->attach_child_devices) +		(pdata->attach_child_devices)(&pdev->dev); + +	hdq_priv.pdata = pdata; + +	return 0; +} + +static int hdq_remove(struct platform_device *pdev) +{ +	sysfs_remove_group(&pdev->dev.kobj, &hdq_attr_group); +	return 0; +} + +static struct platform_driver hdq_driver = { +	.probe		= hdq_probe, +	.remove		= hdq_remove, +#ifdef CONFIG_PM +	.suspend	= hdq_suspend, +	.resume		= hdq_resume, +#endif +	.driver		= { +		.name		= "hdq", +	}, +}; + +static int __init hdq_init(void) +{ +	return platform_driver_register(&hdq_driver); +} + +static void __exit hdq_exit(void) +{ + 	platform_driver_unregister(&hdq_driver); +} + +module_init(hdq_init); +module_exit(hdq_exit); + +MODULE_AUTHOR("Andy Green <andy@openmoko.com>"); +MODULE_DESCRIPTION("HDQ driver"); | 
