mfd: Rename twl4030* driver files to enable re-use

The upcoming TWL6030 is companion chip for OMAP4 like the current TWL4030
for OMAP3. The common modules like RTC, Regulator creates opportunity
to re-use the most of the code from twl4030.

This patch renames few common drivers twl4030* files to twl* to enable
the code re-use.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 540 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c
new file mode 100644
index 000000000000..93565be12fae
--- /dev/null
+++ b/drivers/rtc/rtc-twl.c
@@ -0,0 +1,540 @@
+/*
+ * rtc-twl4030.c -- TWL4030 Real Time Clock interface
+ *
+ * Copyright (C) 2007 MontaVista Software, Inc
+ * Author: Alexandre Rusev <source@mvista.com>
+ *
+ * Based on original TI driver twl4030-rtc.c
+ *   Copyright (C) 2006 Texas Instruments, Inc.
+ *
+ * Based on rtc-omap.c
+ *   Copyright (C) 2003 MontaVista Software, Inc.
+ *   Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
+ *   Copyright (C) 2006 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+
+#include <linux/i2c/twl.h>
+
+
+/*
+ * RTC block register offsets (use TWL_MODULE_RTC)
+ */
+#define REG_SECONDS_REG                          0x00
+#define REG_MINUTES_REG                          0x01
+#define REG_HOURS_REG                            0x02
+#define REG_DAYS_REG                             0x03
+#define REG_MONTHS_REG                           0x04
+#define REG_YEARS_REG                            0x05
+#define REG_WEEKS_REG                            0x06
+
+#define REG_ALARM_SECONDS_REG                    0x07
+#define REG_ALARM_MINUTES_REG                    0x08
+#define REG_ALARM_HOURS_REG                      0x09
+#define REG_ALARM_DAYS_REG                       0x0A
+#define REG_ALARM_MONTHS_REG                     0x0B
+#define REG_ALARM_YEARS_REG                      0x0C
+
+#define REG_RTC_CTRL_REG                         0x0D
+#define REG_RTC_STATUS_REG                       0x0E
+#define REG_RTC_INTERRUPTS_REG                   0x0F
+
+#define REG_RTC_COMP_LSB_REG                     0x10
+#define REG_RTC_COMP_MSB_REG                     0x11
+
+/* RTC_CTRL_REG bitfields */
+#define BIT_RTC_CTRL_REG_STOP_RTC_M              0x01
+#define BIT_RTC_CTRL_REG_ROUND_30S_M             0x02
+#define BIT_RTC_CTRL_REG_AUTO_COMP_M             0x04
+#define BIT_RTC_CTRL_REG_MODE_12_24_M            0x08
+#define BIT_RTC_CTRL_REG_TEST_MODE_M             0x10
+#define BIT_RTC_CTRL_REG_SET_32_COUNTER_M        0x20
+#define BIT_RTC_CTRL_REG_GET_TIME_M              0x40
+
+/* RTC_STATUS_REG bitfields */
+#define BIT_RTC_STATUS_REG_RUN_M                 0x02
+#define BIT_RTC_STATUS_REG_1S_EVENT_M            0x04
+#define BIT_RTC_STATUS_REG_1M_EVENT_M            0x08
+#define BIT_RTC_STATUS_REG_1H_EVENT_M            0x10
+#define BIT_RTC_STATUS_REG_1D_EVENT_M            0x20
+#define BIT_RTC_STATUS_REG_ALARM_M               0x40
+#define BIT_RTC_STATUS_REG_POWER_UP_M            0x80
+
+/* RTC_INTERRUPTS_REG bitfields */
+#define BIT_RTC_INTERRUPTS_REG_EVERY_M           0x03
+#define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M        0x04
+#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M        0x08
+
+
+/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
+#define ALL_TIME_REGS		6
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * Supports 1 byte read from TWL4030 RTC register.
+ */
+static int twl4030_rtc_read_u8(u8 *data, u8 reg)
+{
+	int ret;
+
+	ret = twl4030_i2c_read_u8(TWL4030_MODULE_RTC, data, reg);
+	if (ret < 0)
+		pr_err("twl4030_rtc: Could not read TWL4030"
+		       "register %X - error %d\n", reg, ret);
+	return ret;
+}
+
+/*
+ * Supports 1 byte write to TWL4030 RTC registers.
+ */
+static int twl4030_rtc_write_u8(u8 data, u8 reg)
+{
+	int ret;
+
+	ret = twl4030_i2c_write_u8(TWL4030_MODULE_RTC, data, reg);
+	if (ret < 0)
+		pr_err("twl4030_rtc: Could not write TWL4030"
+		       "register %X - error %d\n", reg, ret);
+	return ret;
+}
+
+/*
+ * Cache the value for timer/alarm interrupts register; this is
+ * only changed by callers holding rtc ops lock (or resume).
+ */
+static unsigned char rtc_irq_bits;
+
+/*
+ * Enable 1/second update and/or alarm interrupts.
+ */
+static int set_rtc_irq_bit(unsigned char bit)
+{
+	unsigned char val;
+	int ret;
+
+	val = rtc_irq_bits | bit;
+	val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M;
+	ret = twl4030_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
+	if (ret == 0)
+		rtc_irq_bits = val;
+
+	return ret;
+}
+
+/*
+ * Disable update and/or alarm interrupts.
+ */
+static int mask_rtc_irq_bit(unsigned char bit)
+{
+	unsigned char val;
+	int ret;
+
+	val = rtc_irq_bits & ~bit;
+	ret = twl4030_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
+	if (ret == 0)
+		rtc_irq_bits = val;
+
+	return ret;
+}
+
+static int twl4030_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
+{
+	int ret;
+
+	if (enabled)
+		ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+	else
+		ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+
+	return ret;
+}
+
+static int twl4030_rtc_update_irq_enable(struct device *dev, unsigned enabled)
+{
+	int ret;
+
+	if (enabled)
+		ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+	else
+		ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+
+	return ret;
+}
+
+/*
+ * Gets current TWL4030 RTC time and date parameters.
+ *
+ * The RTC's time/alarm representation is not what gmtime(3) requires
+ * Linux to use:
+ *
+ *  - Months are 1..12 vs Linux 0-11
+ *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
+ */
+static int twl4030_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned char rtc_data[ALL_TIME_REGS + 1];
+	int ret;
+	u8 save_control;
+
+	ret = twl4030_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
+	if (ret < 0)
+		return ret;
+
+	save_control |= BIT_RTC_CTRL_REG_GET_TIME_M;
+
+	ret = twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+	if (ret < 0)
+		return ret;
+
+	ret = twl4030_i2c_read(TWL4030_MODULE_RTC, rtc_data,
+			       REG_SECONDS_REG, ALL_TIME_REGS);
+
+	if (ret < 0) {
+		dev_err(dev, "rtc_read_time error %d\n", ret);
+		return ret;
+	}
+
+	tm->tm_sec = bcd2bin(rtc_data[0]);
+	tm->tm_min = bcd2bin(rtc_data[1]);
+	tm->tm_hour = bcd2bin(rtc_data[2]);
+	tm->tm_mday = bcd2bin(rtc_data[3]);
+	tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
+	tm->tm_year = bcd2bin(rtc_data[5]) + 100;
+
+	return ret;
+}
+
+static int twl4030_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+	unsigned char save_control;
+	unsigned char rtc_data[ALL_TIME_REGS + 1];
+	int ret;
+
+	rtc_data[1] = bin2bcd(tm->tm_sec);
+	rtc_data[2] = bin2bcd(tm->tm_min);
+	rtc_data[3] = bin2bcd(tm->tm_hour);
+	rtc_data[4] = bin2bcd(tm->tm_mday);
+	rtc_data[5] = bin2bcd(tm->tm_mon + 1);
+	rtc_data[6] = bin2bcd(tm->tm_year - 100);
+
+	/* Stop RTC while updating the TC registers */
+	ret = twl4030_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
+	if (ret < 0)
+		goto out;
+
+	save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
+	twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+	if (ret < 0)
+		goto out;
+
+	/* update all the time registers in one shot */
+	ret = twl4030_i2c_write(TWL4030_MODULE_RTC, rtc_data,
+			REG_SECONDS_REG, ALL_TIME_REGS);
+	if (ret < 0) {
+		dev_err(dev, "rtc_set_time error %d\n", ret);
+		goto out;
+	}
+
+	/* Start back RTC */
+	save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M;
+	ret = twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+
+out:
+	return ret;
+}
+
+/*
+ * Gets current TWL4030 RTC alarm time.
+ */
+static int twl4030_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	unsigned char rtc_data[ALL_TIME_REGS + 1];
+	int ret;
+
+	ret = twl4030_i2c_read(TWL4030_MODULE_RTC, rtc_data,
+			       REG_ALARM_SECONDS_REG, ALL_TIME_REGS);
+	if (ret < 0) {
+		dev_err(dev, "rtc_read_alarm error %d\n", ret);
+		return ret;
+	}
+
+	/* some of these fields may be wildcard/"match all" */
+	alm->time.tm_sec = bcd2bin(rtc_data[0]);
+	alm->time.tm_min = bcd2bin(rtc_data[1]);
+	alm->time.tm_hour = bcd2bin(rtc_data[2]);
+	alm->time.tm_mday = bcd2bin(rtc_data[3]);
+	alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1;
+	alm->time.tm_year = bcd2bin(rtc_data[5]) + 100;
+
+	/* report cached alarm enable state */
+	if (rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M)
+		alm->enabled = 1;
+
+	return ret;
+}
+
+static int twl4030_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+	unsigned char alarm_data[ALL_TIME_REGS + 1];
+	int ret;
+
+	ret = twl4030_rtc_alarm_irq_enable(dev, 0);
+	if (ret)
+		goto out;
+
+	alarm_data[1] = bin2bcd(alm->time.tm_sec);
+	alarm_data[2] = bin2bcd(alm->time.tm_min);
+	alarm_data[3] = bin2bcd(alm->time.tm_hour);
+	alarm_data[4] = bin2bcd(alm->time.tm_mday);
+	alarm_data[5] = bin2bcd(alm->time.tm_mon + 1);
+	alarm_data[6] = bin2bcd(alm->time.tm_year - 100);
+
+	/* update all the alarm registers in one shot */
+	ret = twl4030_i2c_write(TWL4030_MODULE_RTC, alarm_data,
+			REG_ALARM_SECONDS_REG, ALL_TIME_REGS);
+	if (ret) {
+		dev_err(dev, "rtc_set_alarm error %d\n", ret);
+		goto out;
+	}
+
+	if (alm->enabled)
+		ret = twl4030_rtc_alarm_irq_enable(dev, 1);
+out:
+	return ret;
+}
+
+static irqreturn_t twl4030_rtc_interrupt(int irq, void *rtc)
+{
+	unsigned long events = 0;
+	int ret = IRQ_NONE;
+	int res;
+	u8 rd_reg;
+
+#ifdef CONFIG_LOCKDEP
+	/* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
+	 * we don't want and can't tolerate.  Although it might be
+	 * friendlier not to borrow this thread context...
+	 */
+	local_irq_enable();
+#endif
+
+	res = twl4030_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
+	if (res)
+		goto out;
+	/*
+	 * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
+	 * only one (ALARM or RTC) interrupt source may be enabled
+	 * at time, we also could check our results
+	 * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
+	 */
+	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
+		events |= RTC_IRQF | RTC_AF;
+	else
+		events |= RTC_IRQF | RTC_UF;
+
+	res = twl4030_rtc_write_u8(rd_reg | BIT_RTC_STATUS_REG_ALARM_M,
+				   REG_RTC_STATUS_REG);
+	if (res)
+		goto out;
+
+	/* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
+	 * needs 2 reads to clear the interrupt. One read is done in
+	 * do_twl4030_pwrirq(). Doing the second read, to clear
+	 * the bit.
+	 *
+	 * FIXME the reason PWR_ISR1 needs an extra read is that
+	 * RTC_IF retriggered until we cleared REG_ALARM_M above.
+	 * But re-reading like this is a bad hack; by doing so we
+	 * risk wrongly clearing status for some other IRQ (losing
+	 * the interrupt).  Be smarter about handling RTC_UF ...
+	 */
+	res = twl4030_i2c_read_u8(TWL4030_MODULE_INT,
+			&rd_reg, TWL4030_INT_PWR_ISR1);
+	if (res)
+		goto out;
+
+	/* Notify RTC core on event */
+	rtc_update_irq(rtc, 1, events);
+
+	ret = IRQ_HANDLED;
+out:
+	return ret;
+}
+
+static struct rtc_class_ops twl4030_rtc_ops = {
+	.read_time	= twl4030_rtc_read_time,
+	.set_time	= twl4030_rtc_set_time,
+	.read_alarm	= twl4030_rtc_read_alarm,
+	.set_alarm	= twl4030_rtc_set_alarm,
+	.alarm_irq_enable = twl4030_rtc_alarm_irq_enable,
+	.update_irq_enable = twl4030_rtc_update_irq_enable,
+};
+
+/*----------------------------------------------------------------------*/
+
+static int __devinit twl4030_rtc_probe(struct platform_device *pdev)
+{
+	struct rtc_device *rtc;
+	int ret = 0;
+	int irq = platform_get_irq(pdev, 0);
+	u8 rd_reg;
+
+	if (irq <= 0)
+		return -EINVAL;
+
+	rtc = rtc_device_register(pdev->name,
+				  &pdev->dev, &twl4030_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc)) {
+		ret = PTR_ERR(rtc);
+		dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
+			PTR_ERR(rtc));
+		goto out0;
+
+	}
+
+	platform_set_drvdata(pdev, rtc);
+
+	ret = twl4030_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
+	if (ret < 0)
+		goto out1;
+
+	if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
+		dev_warn(&pdev->dev, "Power up reset detected.\n");
+
+	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
+		dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");
+
+	/* Clear RTC Power up reset and pending alarm interrupts */
+	ret = twl4030_rtc_write_u8(rd_reg, REG_RTC_STATUS_REG);
+	if (ret < 0)
+		goto out1;
+
+	ret = request_irq(irq, twl4030_rtc_interrupt,
+				IRQF_TRIGGER_RISING,
+				dev_name(&rtc->dev), rtc);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "IRQ is not free.\n");
+		goto out1;
+	}
+
+	/* Check RTC module status, Enable if it is off */
+	ret = twl4030_rtc_read_u8(&rd_reg, REG_RTC_CTRL_REG);
+	if (ret < 0)
+		goto out2;
+
+	if (!(rd_reg & BIT_RTC_CTRL_REG_STOP_RTC_M)) {
+		dev_info(&pdev->dev, "Enabling TWL4030-RTC.\n");
+		rd_reg = BIT_RTC_CTRL_REG_STOP_RTC_M;
+		ret = twl4030_rtc_write_u8(rd_reg, REG_RTC_CTRL_REG);
+		if (ret < 0)
+			goto out2;
+	}
+
+	/* init cached IRQ enable bits */
+	ret = twl4030_rtc_read_u8(&rtc_irq_bits, REG_RTC_INTERRUPTS_REG);
+	if (ret < 0)
+		goto out2;
+
+	return ret;
+
+out2:
+	free_irq(irq, rtc);
+out1:
+	rtc_device_unregister(rtc);
+out0:
+	return ret;
+}
+
+/*
+ * Disable all TWL4030 RTC module interrupts.
+ * Sets status flag to free.
+ */
+static int __devexit twl4030_rtc_remove(struct platform_device *pdev)
+{
+	/* leave rtc running, but disable irqs */
+	struct rtc_device *rtc = platform_get_drvdata(pdev);
+	int irq = platform_get_irq(pdev, 0);
+
+	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+
+	free_irq(irq, rtc);
+
+	rtc_device_unregister(rtc);
+	platform_set_drvdata(pdev, NULL);
+	return 0;
+}
+
+static void twl4030_rtc_shutdown(struct platform_device *pdev)
+{
+	/* mask timer interrupts, but leave alarm interrupts on to enable
+	   power-on when alarm is triggered */
+	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+}
+
+#ifdef CONFIG_PM
+
+static unsigned char irqstat;
+
+static int twl4030_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+	irqstat = rtc_irq_bits;
+
+	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+	return 0;
+}
+
+static int twl4030_rtc_resume(struct platform_device *pdev)
+{
+	set_rtc_irq_bit(irqstat);
+	return 0;
+}
+
+#else
+#define twl4030_rtc_suspend NULL
+#define twl4030_rtc_resume  NULL
+#endif
+
+MODULE_ALIAS("platform:twl4030_rtc");
+
+static struct platform_driver twl4030rtc_driver = {
+	.probe		= twl4030_rtc_probe,
+	.remove		= __devexit_p(twl4030_rtc_remove),
+	.shutdown	= twl4030_rtc_shutdown,
+	.suspend	= twl4030_rtc_suspend,
+	.resume		= twl4030_rtc_resume,
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= "twl4030_rtc",
+	},
+};
+
+static int __init twl4030_rtc_init(void)
+{
+	return platform_driver_register(&twl4030rtc_driver);
+}
+module_init(twl4030_rtc_init);
+
+static void __exit twl4030_rtc_exit(void)
+{
+	platform_driver_unregister(&twl4030rtc_driver);
+}
+module_exit(twl4030_rtc_exit);
+
+MODULE_AUTHOR("Texas Instruments, MontaVista Software");
+MODULE_LICENSE("GPL");