[U-Boot] [PATCH] Add driver for the ST M41T94 SPI RTC

[U-Boot] [PATCH] Add driver for the ST M41T94 SPI RTC

[Albin Tonnerre]

This RTC is used in some Calao boards. The driver code is taken from the
linux rtc-m41t94 driver

Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
---

I guess the bin2bcd and bcd2bin functions belong somewhere in common/ rather
than this particular driver ... Where should I put them ?

 drivers/rtc/Makefile |    1 +
 drivers/rtc/m41t94.c |  137 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 138 insertions(+), 0 deletions(-)
 create mode 100644 drivers/rtc/m41t94.c

diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 822dc1a..ea7d899 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -44,6 +44,7 @@ COBJS-$(CONFIG_RTC_ISL1208) += isl1208.o
 COBJS-$(CONFIG_RTC_M41T11) += m41t11.o
 COBJS-$(CONFIG_RTC_M41T60) += m41t60.o
 COBJS-$(CONFIG_RTC_M41T62) += m41t62.o
+COBJS-$(CONFIG_RTC_M41T94) += m41t94.o
 COBJS-$(CONFIG_RTC_M48T35A) += m48t35ax.o
 COBJS-$(CONFIG_RTC_MAX6900) += max6900.o
 COBJS-$(CONFIG_RTC_MC13783) += mc13783-rtc.o
diff --git a/drivers/rtc/m41t94.c b/drivers/rtc/m41t94.c
new file mode 100644
index 0000000..6e828a7
--- /dev/null
+++ b/drivers/rtc/m41t94.c
@@ -0,0 +1,137 @@
+/*
+ * Driver for ST M41T94 SPI RTC
+ *
+ * Taken from the Linux kernel drivier:
+ * Copyright (C) 2008 Kim B. Heino
+ *
+ * Adaptation for U-Boot:
+ * Copyright (C) 2009
+ * Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.com>
+ *
+ * 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 <common.h>
+#include <rtc.h>
+#include <spi.h>
+
+static struct spi_slave *slave;
+
+#define M41T94_REG_SECONDS	0x01
+#define M41T94_REG_MINUTES	0x02
+#define M41T94_REG_HOURS	0x03
+#define M41T94_REG_WDAY		0x04
+#define M41T94_REG_DAY		0x05
+#define M41T94_REG_MONTH	0x06
+#define M41T94_REG_YEAR		0x07
+#define M41T94_REG_HT		0x0c
+
+#define M41T94_BIT_HALT		0x40
+#define M41T94_BIT_STOP		0x80
+#define M41T94_BIT_CB		0x40
+#define M41T94_BIT_CEB		0x80
+
+static unsigned bcd2bin (uchar n);
+static unsigned char bin2bcd (unsigned int n);
+
+int rtc_set(struct rtc_time *tm)
+{
+	u8 buf[8]; /* write cmd + 7 registers */
+	int ret;
+
+	if (!slave) {
+		slave = spi_setup_slave(CONFIG_M41T94_SPI_BUS,
+					CONFIG_M41T94_SPI_CS, 1000000,
+					SPI_MODE_3);
+		if (!slave)
+			return -1;
+	}
+	spi_claim_bus(slave);
+
+	buf[0] = 0x80 | M41T94_REG_SECONDS; /* write time + date */
+	buf[M41T94_REG_SECONDS] = bin2bcd(tm->tm_sec);
+	buf[M41T94_REG_MINUTES] = bin2bcd(tm->tm_min);
+	buf[M41T94_REG_HOURS]   = bin2bcd(tm->tm_hour);
+	buf[M41T94_REG_WDAY]    = bin2bcd(tm->tm_wday + 1);
+	buf[M41T94_REG_DAY]     = bin2bcd(tm->tm_mday);
+	buf[M41T94_REG_MONTH]   = bin2bcd(tm->tm_mon + 1);
+
+	buf[M41T94_REG_HOURS] |= M41T94_BIT_CEB;
+	if (tm->tm_year >= 100)
+		buf[M41T94_REG_HOURS] |= M41T94_BIT_CB;
+	buf[M41T94_REG_YEAR] = bin2bcd(tm->tm_year % 100);
+
+	ret = spi_xfer(slave, 64, buf, NULL, SPI_XFER_BEGIN | SPI_XFER_END);
+	spi_release_bus(slave);
+	return ret;
+}
+
+int rtc_get(struct rtc_time *tm)
+{
+	u8 buf[2];
+	int ret, hour;
+
+	if (!slave) {
+		slave = spi_setup_slave(CONFIG_M41T94_SPI_BUS,
+					CONFIG_M41T94_SPI_CS, 1000000,
+					SPI_MODE_3);
+		if (!slave)
+			return -1;
+	}
+	spi_claim_bus(slave);
+
+	/* clear halt update bit */
+	ret = spi_w8r8(slave, M41T94_REG_HT);
+	if (ret < 0)
+		return ret;
+	if (ret & M41T94_BIT_HALT) {
+		buf[0] = 0x80 | M41T94_REG_HT;
+		buf[1] = ret & ~M41T94_BIT_HALT;
+		spi_xfer(slave, 16, buf, NULL, SPI_XFER_BEGIN | SPI_XFER_END);
+	}
+
+	/* clear stop bit */
+	ret = spi_w8r8(slave, M41T94_REG_SECONDS);
+	if (ret < 0)
+		return ret;
+	if (ret & M41T94_BIT_STOP) {
+		buf[0] = 0x80 | M41T94_REG_SECONDS;
+		buf[1] = ret & ~M41T94_BIT_STOP;
+		spi_xfer(slave, 16, buf, NULL, SPI_XFER_BEGIN | SPI_XFER_END);
+	}
+
+	tm->tm_sec  = bcd2bin(spi_w8r8(slave, M41T94_REG_SECONDS));
+	tm->tm_min  = bcd2bin(spi_w8r8(slave, M41T94_REG_MINUTES));
+	hour = spi_w8r8(slave, M41T94_REG_HOURS);
+	tm->tm_hour = bcd2bin(hour & 0x3f);
+	tm->tm_wday = bcd2bin(spi_w8r8(slave, M41T94_REG_WDAY)) - 1;
+	tm->tm_mday = bcd2bin(spi_w8r8(slave, M41T94_REG_DAY));
+	tm->tm_mon  = bcd2bin(spi_w8r8(slave, M41T94_REG_MONTH)) - 1;
+	tm->tm_year = bcd2bin(spi_w8r8(slave, M41T94_REG_YEAR));
+	if ((hour & M41T94_BIT_CB) || !(hour & M41T94_BIT_CEB))
+		tm->tm_year += 100;
+
+	spi_release_bus(slave);
+	return 0;
+}
+
+void rtc_reset(void)
+{
+	/*
+	 * Could not be tested as the reset pin is not wired on
+	 * the sbc35-ag20 board
+	 */
+	return 0;
+}
+
+static unsigned bcd2bin (uchar n)
+{
+	return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
+}
+
+static unsigned char bin2bcd (unsigned int n)
+{
+	return (((n / 10) << 4) | (n % 10));
+}
-- 
1.6.0.4

[U-Boot] [PATCH] Add driver for the ST M41T94 SPI RTC

[Stefan Roese]

On Thursday 13 August 2009 12:14:30 Albin Tonnerre wrote:
> This RTC is used in some Calao boards. The driver code is taken from the
> linux rtc-m41t94 driver
>
> Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
> ---
>
> I guess the bin2bcd and bcd2bin functions belong somewhere in common/
> rather than this particular driver ... Where should I put them ?

Currently we also have BIN2BCD/BCD2BIN macros in include/bcd.h. We should 
probably move to these lowercase inlined functions though. Perhaps you could 
create a patch to switch from BIN2BCD to bin2bcd in the RTC drivers and add 
those functions to bcd.h?

Thanks.

Cheers,
Stefan

--
DENX Software Engineering GmbH,      MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich,  Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-0 Fax: (+49)-8142-66989-80 Email: office at denx.de

[U-Boot] [PATCH] Add driver for the ST M41T94 SPI RTC

[Albin Tonnerre]

On Thu, Aug 13, 2009 at 01:05:37PM +0200, Stefan Roese wrote :
> On Thursday 13 August 2009 12:14:30 Albin Tonnerre wrote:
> > This RTC is used in some Calao boards. The driver code is taken from the
> > linux rtc-m41t94 driver
> >
> > Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
> > ---
> >
> > I guess the bin2bcd and bcd2bin functions belong somewhere in common/
> > rather than this particular driver ... Where should I put them ?
> 
> Currently we also have BIN2BCD/BCD2BIN macros in include/bcd.h. We should 
> probably move to these lowercase inlined functions though. Perhaps you could 
> create a patch to switch from BIN2BCD to bin2bcd in the RTC drivers and add 
> those functions to bcd.h?

Heh, I see that nearly all the rtc drivers define those functions too ... Will
submit a patch to clean that up

Regards,
-- 
Albin Tonnerre, Free Electrons
Kernel, drivers and embedded Linux development,
consulting, training and support.
http://free-electrons.com

[U-Boot] [PATCH v2] Add driver for the ST M41T94 SPI RTC

[Albin Tonnerre]

This RTC is used in some Calao boards. The driver code is taken from the
linux rtc-m41t94 driver

Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
---
Changelog since V1:
 - Use the common bin2bcd/bcd2bin functions. This patch depends on:
   1250170272-25909-2-git-send-email-albin.tonnerre at free-electrons.com

 drivers/rtc/Makefile |    1 +
 drivers/rtc/m41t94.c |  124 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 125 insertions(+), 0 deletions(-)
 create mode 100644 drivers/rtc/m41t94.c

diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 822dc1a..ea7d899 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -44,6 +44,7 @@ COBJS-$(CONFIG_RTC_ISL1208) += isl1208.o
 COBJS-$(CONFIG_RTC_M41T11) += m41t11.o
 COBJS-$(CONFIG_RTC_M41T60) += m41t60.o
 COBJS-$(CONFIG_RTC_M41T62) += m41t62.o
+COBJS-$(CONFIG_RTC_M41T94) += m41t94.o
 COBJS-$(CONFIG_RTC_M48T35A) += m48t35ax.o
 COBJS-$(CONFIG_RTC_MAX6900) += max6900.o
 COBJS-$(CONFIG_RTC_MC13783) += mc13783-rtc.o
diff --git a/drivers/rtc/m41t94.c b/drivers/rtc/m41t94.c
new file mode 100644
index 0000000..02b41d9
--- /dev/null
+++ b/drivers/rtc/m41t94.c
@@ -0,0 +1,124 @@
+/*
+ * Driver for ST M41T94 SPI RTC
+ *
+ * Taken from the Linux kernel drivier:
+ * Copyright (C) 2008 Kim B. Heino
+ *
+ * Adaptation for U-Boot:
+ * Copyright (C) 2009
+ * Albin Tonnerre, Free Electrons <albin.tonnerre@free-electrons.com>
+ *
+ * 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 <common.h>
+#include <rtc.h>
+#include <spi.h>
+
+static struct spi_slave *slave;
+
+#define M41T94_REG_SECONDS	0x01
+#define M41T94_REG_MINUTES	0x02
+#define M41T94_REG_HOURS	0x03
+#define M41T94_REG_WDAY		0x04
+#define M41T94_REG_DAY		0x05
+#define M41T94_REG_MONTH	0x06
+#define M41T94_REG_YEAR		0x07
+#define M41T94_REG_HT		0x0c
+
+#define M41T94_BIT_HALT		0x40
+#define M41T94_BIT_STOP		0x80
+#define M41T94_BIT_CB		0x40
+#define M41T94_BIT_CEB		0x80
+
+int rtc_set(struct rtc_time *tm)
+{
+	u8 buf[8]; /* write cmd + 7 registers */
+	int ret;
+
+	if (!slave) {
+		slave = spi_setup_slave(CONFIG_M41T94_SPI_BUS,
+					CONFIG_M41T94_SPI_CS, 1000000,
+					SPI_MODE_3);
+		if (!slave)
+			return -1;
+	}
+	spi_claim_bus(slave);
+
+	buf[0] = 0x80 | M41T94_REG_SECONDS; /* write time + date */
+	buf[M41T94_REG_SECONDS] = bin2bcd(tm->tm_sec);
+	buf[M41T94_REG_MINUTES] = bin2bcd(tm->tm_min);
+	buf[M41T94_REG_HOURS]   = bin2bcd(tm->tm_hour);
+	buf[M41T94_REG_WDAY]    = bin2bcd(tm->tm_wday + 1);
+	buf[M41T94_REG_DAY]     = bin2bcd(tm->tm_mday);
+	buf[M41T94_REG_MONTH]   = bin2bcd(tm->tm_mon + 1);
+
+	buf[M41T94_REG_HOURS] |= M41T94_BIT_CEB;
+	if (tm->tm_year >= 100)
+		buf[M41T94_REG_HOURS] |= M41T94_BIT_CB;
+	buf[M41T94_REG_YEAR] = bin2bcd(tm->tm_year % 100);
+
+	ret = spi_xfer(slave, 64, buf, NULL, SPI_XFER_BEGIN | SPI_XFER_END);
+	spi_release_bus(slave);
+	return ret;
+}
+
+int rtc_get(struct rtc_time *tm)
+{
+	u8 buf[2];
+	int ret, hour;
+
+	if (!slave) {
+		slave = spi_setup_slave(CONFIG_M41T94_SPI_BUS,
+					CONFIG_M41T94_SPI_CS, 1000000,
+					SPI_MODE_3);
+		if (!slave)
+			return -1;
+	}
+	spi_claim_bus(slave);
+
+	/* clear halt update bit */
+	ret = spi_w8r8(slave, M41T94_REG_HT);
+	if (ret < 0)
+		return ret;
+	if (ret & M41T94_BIT_HALT) {
+		buf[0] = 0x80 | M41T94_REG_HT;
+		buf[1] = ret & ~M41T94_BIT_HALT;
+		spi_xfer(slave, 16, buf, NULL, SPI_XFER_BEGIN | SPI_XFER_END);
+	}
+
+	/* clear stop bit */
+	ret = spi_w8r8(slave, M41T94_REG_SECONDS);
+	if (ret < 0)
+		return ret;
+	if (ret & M41T94_BIT_STOP) {
+		buf[0] = 0x80 | M41T94_REG_SECONDS;
+		buf[1] = ret & ~M41T94_BIT_STOP;
+		spi_xfer(slave, 16, buf, NULL, SPI_XFER_BEGIN | SPI_XFER_END);
+	}
+
+	tm->tm_sec  = bcd2bin(spi_w8r8(slave, M41T94_REG_SECONDS));
+	tm->tm_min  = bcd2bin(spi_w8r8(slave, M41T94_REG_MINUTES));
+	hour = spi_w8r8(slave, M41T94_REG_HOURS);
+	tm->tm_hour = bcd2bin(hour & 0x3f);
+	tm->tm_wday = bcd2bin(spi_w8r8(slave, M41T94_REG_WDAY)) - 1;
+	tm->tm_mday = bcd2bin(spi_w8r8(slave, M41T94_REG_DAY));
+	tm->tm_mon  = bcd2bin(spi_w8r8(slave, M41T94_REG_MONTH)) - 1;
+	tm->tm_year = bcd2bin(spi_w8r8(slave, M41T94_REG_YEAR));
+	if ((hour & M41T94_BIT_CB) || !(hour & M41T94_BIT_CEB))
+		tm->tm_year += 100;
+
+	spi_release_bus(slave);
+	return 0;
+}
+
+void rtc_reset(void)
+{
+	/*
+	 * Could not be tested as the reset pin is not wired on
+	 * the sbc35-ag20 board
+	 */
+	return 0;
+}
-- 
1.6.0.4

[U-Boot] [PATCH v2] Add driver for the ST M41T94 SPI RTC

[Wolfgang Denk]

Dear Albin Tonnerre,

In message <1250183564-6140-1-git-send-email-albin.tonnerre@free-electrons.com> you wrote:
> This RTC is used in some Calao boards. The driver code is taken from the
> linux rtc-m41t94 driver
> 
> Signed-off-by: Albin Tonnerre <albin.tonnerre@free-electrons.com>
> ---
> Changelog since V1:
>  - Use the common bin2bcd/bcd2bin functions. This patch depends on:
>    1250170272-25909-2-git-send-email-albin.tonnerre at free-electrons.com
> 
>  drivers/rtc/Makefile |    1 +
>  drivers/rtc/m41t94.c |  124 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 125 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/rtc/m41t94.c

Aplied to "next", thanks.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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