From db07c447caacd5f9003a57ef2802afa8a4c81348 Mon Sep 17 00:00:00 2001
From: Chuanhua Han <chuanhua.han@nxp.com>
Date: Fri, 26 Jul 2019 19:24:00 +0800
Subject: [PATCH] rtc: ds3232/ds3231: Add support to generate 32KHz output for
 driver module

Add an implementation of the rtc_enable_32khz_output() that uses the
driver model i2c APIs.

Also put code related to rtc_enable_32khz_output
under CONFIG_RTC_ENABLE_32KHZ_OUTPUT.

Signed-off-by: Chuanhua Han <chuanhua.han@nxp.com>
Reviewed-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
---
 board/freescale/ls2080aqds/ls2080aqds.c |  2 ++
 drivers/rtc/Kconfig                     |  6 ++++++
 drivers/rtc/ds3231.c                    | 17 +++++++++++++++++
 include/configs/ls2080aqds.h            |  1 +
 include/rtc.h                           |  6 ++++++
 5 files changed, 32 insertions(+)

diff --git a/board/freescale/ls2080aqds/ls2080aqds.c b/board/freescale/ls2080aqds/ls2080aqds.c
index e9c055745f6..dc239cf35ce 100644
--- a/board/freescale/ls2080aqds/ls2080aqds.c
+++ b/board/freescale/ls2080aqds/ls2080aqds.c
@@ -225,7 +225,9 @@ int board_init(void)
 	gd->env_addr = (ulong)&default_environment[0];
 #endif
 	select_i2c_ch_pca9547(I2C_MUX_CH_DEFAULT);
+#ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
 	rtc_enable_32khz_output();
+#endif
 #ifdef CONFIG_FSL_CAAM
 	sec_init();
 #endif
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 860b73d3690..8778cc7b264 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -31,6 +31,12 @@ config TPL_DM_RTC
 	  drivers to perform the actual functions. See rtc.h for a
 	  description of the API.
 
+config RTC_ENABLE_32KHZ_OUTPUT
+	bool "Enable RTC 32Khz output"
+	help
+	   Some real-time clocks support the output of 32kHz square waves (such as ds3231),
+	   the config symbol choose Real Time Clock device 32Khz output feature.
+
 config RTC_PCF2127
 	bool "Enable PCF2127 driver"
 	depends on DM_RTC
diff --git a/drivers/rtc/ds3231.c b/drivers/rtc/ds3231.c
index 79b026af4b9..fde4d860ec1 100644
--- a/drivers/rtc/ds3231.c
+++ b/drivers/rtc/ds3231.c
@@ -148,11 +148,13 @@ void rtc_reset (void)
 /*
  * Enable 32KHz output
  */
+#ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
 void rtc_enable_32khz_output(void)
 {
 	rtc_write(RTC_STAT_REG_ADDR,
 		  RTC_STAT_BIT_BB32KHZ | RTC_STAT_BIT_EN32KHZ);
 }
+#endif
 
 /*
  * Helper functions
@@ -251,6 +253,21 @@ static int ds3231_probe(struct udevice *dev)
 	return 0;
 }
 
+#ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
+int rtc_enable_32khz_output(int busnum, int chip_addr)
+{
+	int ret;
+	struct udevice *dev;
+
+	ret = i2c_get_chip_for_busnum(busnum, chip_addr, 1, &dev);
+	if (!ret)
+		ret = dm_i2c_reg_write(dev, RTC_STAT_REG_ADDR,
+				       RTC_STAT_BIT_BB32KHZ |
+				       RTC_STAT_BIT_EN32KHZ);
+	return ret;
+}
+#endif
+
 static const struct rtc_ops ds3231_rtc_ops = {
 	.get = ds3231_rtc_get,
 	.set = ds3231_rtc_set,
diff --git a/include/configs/ls2080aqds.h b/include/configs/ls2080aqds.h
index 18f30b585c4..81af1d9ea43 100644
--- a/include/configs/ls2080aqds.h
+++ b/include/configs/ls2080aqds.h
@@ -325,6 +325,7 @@ unsigned long get_board_ddr_clk(void);
 #define RTC
 #define CONFIG_RTC_DS3231               1
 #define CONFIG_SYS_I2C_RTC_ADDR         0x68
+#define CONFIG_RTC_ENABLE_32KHZ_OUTPUT
 
 /* EEPROM */
 #define CONFIG_ID_EEPROM
diff --git a/include/rtc.h b/include/rtc.h
index b255bdc7a33..7386d52db1d 100644
--- a/include/rtc.h
+++ b/include/rtc.h
@@ -166,11 +166,17 @@ int rtc_read32(struct udevice *dev, unsigned int reg, u32 *valuep);
  */
 int rtc_write32(struct udevice *dev, unsigned int reg, u32 value);
 
+#ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
+int rtc_enable_32khz_output(int busnum, int chip_addr);
+#endif
+
 #else
 int rtc_get (struct rtc_time *);
 int rtc_set (struct rtc_time *);
 void rtc_reset (void);
+#ifdef CONFIG_RTC_ENABLE_32KHZ_OUTPUT
 void rtc_enable_32khz_output(void);
+#endif
 
 /**
  * rtc_read8() - Read an 8-bit register
-- 
2.39.2