rtc: imxdi: Initial support

Add support for Freescale's i.MX DryIce RTC, present on i.MX25.

Signed-off-by Beno?t Th?baudeau <[email protected]>

Cc Wolfgang Denk <[email protected]>

Cc Stefano Babic <[email protected]>

---
 .../drivers/rtc/Makefile                           |    1 +
 /dev/null => u-boot-66714b1/drivers/rtc/imxdi.c    |  224
 ++++++++++++++++++++
 2 files changed, 225 insertions(+)
 create mode 100644 u-boot-66714b1/drivers/rtc/imxdi.c

(quoted diff) +0 -0

u-boot-66714b1/drivers/rtc/Makefile
index faf4fcd..aeeea37 100644

drivers/rtc/Makefile +1 -0

@@ -43,6 +43,7 @@ COBJS-$(CONFIG_RTC_DS164x) += ds164x.o
 COBJS-$(CONFIG_RTC_DS174x) += ds174x.o
 COBJS-$(CONFIG_RTC_DS3231) += ds3231.o
 COBJS-$(CONFIG_RTC_FTRTC010) += ftrtc010.o
+COBJS-$(CONFIG_RTC_IMXDI) += imxdi.o
 COBJS-$(CONFIG_RTC_ISL1208) += isl1208.o
 COBJS-$(CONFIG_RTC_M41T11) += m41t11.o
 COBJS-$(CONFIG_RTC_M41T60) += m41t60.o

(quoted diff) +0 -0

u-boot-66714b1/drivers/rtc/imxdi.c
new file mode 100644
index 0000000..c2be842

drivers/rtc/imxdi.c new file +6 -0

@@ -0,0 +1,224 @@
+/*
+ * (C) Copyright 2009-2012 ADVANSEE
+ * Beno?t Th?baudeau <[email protected]>
+ *
+ * Based on the Linux rtc-imxdi.c driver, which is:
+ * Copyright 2008-2009 Freescale Semiconductor, Inc. All Rights

Reserved.
+ * Copyright 2010 Orex Computed Radiography
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */

drivers/rtc/imxdi.c new file +38 -0

+
+/*
+ * Date & Time support for Freescale i.MX DryIce RTC
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+
+#if defined(CONFIG_CMD_DATE)
+
+#include <asm/io.h>
+#include <asm/arch/imx-regs.h>
+
+/* DryIce Register Definitions */
+
+#define DTCMR     0x00           /* Time Counter MSB Reg */
+#define DTCLR     0x04           /* Time Counter LSB Reg */
+
+#define DCAMR     0x08           /* Clock Alarm MSB Reg */
+#define DCALR     0x0c           /* Clock Alarm LSB Reg */
+#define DCAMR_UNSET  0xFFFFFFFF  /* doomsday - 1 sec */
+
+#define DCR       0x10           /* Control Reg */
+#define DCR_TCE   (1 << 3)       /* Time Counter Enable */
+
+#define DSR       0x14           /* Status Reg */
+#define DSR_WBF   (1 << 10)      /* Write Busy Flag */
+#define DSR_WNF   (1 << 9)       /* Write Next Flag */
+#define DSR_WCF   (1 << 8)       /* Write Complete Flag */
+#define DSR_WEF   (1 << 7)       /* Write Error Flag */
+#define DSR_CAF   (1 << 4)       /* Clock Alarm Flag */
+#define DSR_NVF   (1 << 1)       /* Non-Valid Flag */
+#define DSR_SVF   (1 << 0)       /* Security Violation Flag */
+
+#define DIER      0x18           /* Interrupt Enable Reg */
+#define DIER_WNIE (1 << 9)       /* Write Next Interrupt Enable */
+#define DIER_WCIE (1 << 8)       /* Write Complete Interrupt Enable

*/

drivers/rtc/imxdi.c new file +7 -0

+#define DIER_WEIE (1 << 7)       /* Write Error Interrupt Enable */
+#define DIER_CAIE (1 << 4)       /* Clock Alarm Interrupt Enable */
+
+/*
+ * This function attempts to clear the dryice write-error flag.
+ *
+ * A dryice write error is similar to a bus fault and should not

occur in
+ * normal operation. Clearing the flag requires another write, so the root
+ * cause of the problem may need to be fixed before the flag can be cleared.
+ */

drivers/rtc/imxdi.c new file +140 -0

+static void clear_write_error(void)
+{
+	int cnt;
+
+	puts("### Warning: RTC - Register write error!\n");
+
+	/* clear the write error flag */
+	__raw_writel(DSR_WEF, IMX_DRYICE_BASE + DSR);
+
+	/* wait for it to take effect */
+	for (cnt = 0; cnt < 1000; cnt++) {
+		if ((__raw_readl(IMX_DRYICE_BASE + DSR) & DSR_WEF) == 0)
+			return;
+		udelay(10);
+	}
+	puts("### Error: RTC - Cannot clear write-error flag!\n");
+}
+
+/*
+ * Write a dryice register and wait until it completes.
+ *
+ * This function uses interrupt flags to determine when the
+ * write has completed.
+ */
+static int di_write_wait(u32 val, int reg)
+{
+	int cnt;
+	int ret = 0;
+	int rc = 0;
+
+	/* do the register write */
+	__raw_writel(val, IMX_DRYICE_BASE + reg);
+
+	/* wait for the write to finish */
+	for (cnt = 0; cnt < 100; cnt++) {
+		if ((__raw_readl(IMX_DRYICE_BASE + DSR) &
+				(DSR_WCF | DSR_WEF)) != 0) {
+			ret = 1;
+			break;
+		}
+		udelay(10);
+	}
+	if (ret == 0)
+		printf("### Warning: RTC - Write-wait timeout "
+				"val = 0x%.8x reg = 0x%.8x\n", val, reg);
+
+	/* check for write error */
+	if (__raw_readl(IMX_DRYICE_BASE + DSR) & DSR_WEF) {
+		clear_write_error();
+		rc = -1;
+	}
+
+	return rc;
+}
+
+/*
+ * Initialize dryice hardware
+ */
+static int di_init(void)
+{
+	int rc = 0;
+
+	/* mask all interrupts */
+	__raw_writel(0, IMX_DRYICE_BASE + DIER);
+
+	/* put dryice into valid state */
+	if (__raw_readl(IMX_DRYICE_BASE + DSR) & DSR_NVF) {
+		rc = di_write_wait(DSR_NVF | DSR_SVF, DSR);
+		if (rc)
+			goto err;
+	}
+
+	/* initialize alarm */
+	rc = di_write_wait(DCAMR_UNSET, DCAMR);
+	if (rc)
+		goto err;
+	rc = di_write_wait(0, DCALR);
+	if (rc)
+		goto err;
+
+	/* clear alarm flag */
+	if (__raw_readl(IMX_DRYICE_BASE + DSR) & DSR_CAF) {
+		rc = di_write_wait(DSR_CAF, DSR);
+		if (rc)
+			goto err;
+	}
+
+	/* the timer won't count if it has never been written to */
+	if (__raw_readl(IMX_DRYICE_BASE + DTCMR) == 0) {
+		rc = di_write_wait(0, DTCMR);
+		if (rc)
+			goto err;
+	}
+
+	/* start keeping time */
+	if (!(__raw_readl(IMX_DRYICE_BASE + DCR) & DCR_TCE)) {
+		rc = di_write_wait(__raw_readl(IMX_DRYICE_BASE + DCR) | DCR_TCE,
+				DCR);
+		if (rc)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	return rc;
+}
+
+int rtc_get(struct rtc_time *tmp)
+{
+	unsigned long now;
+	int rc;
+
+	rc = di_init();
+	if (rc)
+		goto err;
+
+	now = __raw_readl(IMX_DRYICE_BASE + DTCMR);
+	to_tm(now, tmp);
+
+err:
+	return rc;
+}
+
+int rtc_set(struct rtc_time *tmp)
+{
+	unsigned long now;
+	int rc;
+
+	rc = di_init();
+	if (rc)
+		goto err;
+
+	now = mktime(tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
+	             tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
+	/* zero the fractional part first */
+	rc = di_write_wait(0, DTCLR);
+	if (rc == 0)
+		rc = di_write_wait(now, DTCMR);
+

Add support for Freescale's i.MX DryIce RTC, present on i.MX25.

Signed-off-by Beno?t Th?baudeau <[email protected]>

Cc Wolfgang Denk <[email protected]>

Cc Stefano Babic <[email protected]>

---

drivers/rtc/imxdi.c new file +11 -0

+
+/*
+ * Date & Time support for Freescale i.MX DryIce RTC
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+
+#if defined(CONFIG_CMD_DATE)
+

drivers/rtc/imxdi.c new file +5 -0

+/*
+ * This function attempts to clear the dryice write-error flag.
+ *
+ * A dryice write error is similar to a bus fault and should not occur in
+ * normal operation.  Clearing the flag requires another write, so the root

Quoted 6 lines · Beno?t Th?baudeau

Add support for Freescale's i.MX DryIce RTC, present on i.MX25.

Signed-off-by Beno?t Th?baudeau <[email protected]>

Cc Wolfgang Denk <[email protected]>

Cc Stefano Babic <[email protected]>

---

Hi Benoit,

just a few comments.

Quoted 11 lines

drivers/rtc/imxdi.c new file +11 -0

+
+/*
+ * Date & Time support for Freescale i.MX DryIce RTC
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+
+#if defined(CONFIG_CMD_DATE)
+

drivers/rtc/imxdi.c line 47

Quoted 10 lines

drivers/rtc/imxdi.c new file +10 -0

+#include <asm/io.h>
+#include <asm/arch/imx-regs.h>
+
+/* DryIce Register Definitions */
+
+#define DTCMR     0x00           /* Time Counter MSB Reg */
+#define DTCLR     0x04           /* Time Counter LSB Reg */
+
+#define DCAMR     0x08           /* Clock Alarm MSB Reg */
+#define DCALR     0x0c           /* Clock Alarm LSB Reg */

U-Boot as rule does not allow usage of start address + offset to access
internal registers. Instead of that, please define a proper C structure
with the register's layout. This should be fixed globally for all read /
write accesses.

Quoted 10 lines

+/*
+ * This function attempts to clear the dryice write-error flag.
+ *
+ * A dryice write error is similar to a bus fault and should not occur in
+ * normal operation. Clearing the flag requires another write, so the root
+ * cause of the problem may need to be fixed before the flag can be cleared.
+ */

drivers/rtc/imxdi.c line 82

Quoted 8 lines

drivers/rtc/imxdi.c new file +8 -0

+static void clear_write_error(void)
+{
+	int cnt;
+
+	puts("### Warning: RTC - Register write error!\n");
+
+	/* clear the write error flag */
+	__raw_writel(DSR_WEF, IMX_DRYICE_BASE + DSR);

Ditto

drivers/rtc/imxdi.c line 188

Quoted 6 lines

drivers/rtc/imxdi.c new file +6 -0

+int rtc_get(struct rtc_time *tmp)
+{
+	unsigned long now;
+	int rc;
+
+	rc = di_init();

Why is di_init always called ? Should be not checked if it is was already initialized and the function should be called only once ?

Add support for Freescale's i.MX DryIce RTC, present on i.MX25.

Signed-off-by Beno?t Th?baudeau <[email protected]>

Cc Wolfgang Denk <[email protected]>

Cc Stefano Babic <[email protected]>

---

Add support for Freescale's i.MX DryIce RTC, present on i.MX25.

Signed-off-by Beno?t Th?baudeau <[email protected]>

Cc Wolfgang Denk <[email protected]>

Cc Stefano Babic <[email protected]>

---

Quoted 6 lines · Beno?t Th?baudeau

Add support for Freescale's i.MX DryIce RTC, present on i.MX25.

Signed-off-by Beno?t Th?baudeau <[email protected]>

Cc Wolfgang Denk <[email protected]>

Cc Stefano Babic <[email protected]>

---

Hi Beno?t,

checkpatch reports an error when I run your patch. Can you fix it ?

ERROR: code indent should use tabs where possible
#275: FILE: drivers/rtc/imxdi.c:229:
+^I tmp->tm_hour, tmp->tm_min, tmp->tm_sec);$

Apart of that, here my:

Acked-by Stefano Babic <[email protected]>

Hi Stefano,

Quoted 8 lines · Stefano Babic

Quoted 6 lines · Beno?t Th?baudeau

Add support for Freescale's i.MX DryIce RTC, present on i.MX25.

Signed-off-by Beno?t Th?baudeau <[email protected]>

Cc Wolfgang Denk <[email protected]>

Cc Stefano Babic <[email protected]>

---

Quoted 7 lines

Hi Beno?t,

checkpatch reports an error when I run your patch. Can you fix it ?

ERROR: code indent should use tabs where possible
#275: FILE: drivers/rtc/imxdi.c:229:
+^I tmp->tm_hour, tmp->tm_min, tmp->tm_sec);$

I've just posted a v3 fixing that.

Quoted 3 lines

Apart of that, here my:

Acked-by Stefano Babic <[email protected]>

Thanks. Who is supposed to apply it, and to which repository?