[PATCH] rtc: add support for rtc NXP pca21125 and pca8565

From: Venkat Prashanth B U
Date: Sun Dec 25 2016 - 01:58:54 EST


This is a patch to support the SPI compatible PCA21125 device
with the I2C based rtc-pcf8563 driver using regmap layer.
Further this patch adds "pca8565" to the set of i2c ids.

Signed-off-by: Venkat Prashanth B U <venkat.prashanth2498@xxxxxxxxx>
---
change log v3:
1. Add a regmap layer to I2C PCF8563 to support SPI PCA21125.
2. Add pca8565 to the set of i2c ids of rtc-pcf8563.
---
---
drivers/rtc/rtc-pcf8563.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 82 insertions(+)

diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index 1227cea..26c8b9b 100644
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -22,6 +22,8 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/err.h>
+#include <linux/spi/spi.h>
+#include <linux/regmap.h>

#define PCF8563_REG_ST1 0x00 /* status */
#define PCF8563_REG_ST2 0x01
@@ -59,6 +61,7 @@

#define PCF8563_SC_LV 0x80 /* low voltage */
#define PCF8563_MO_C 0x80 /* century */
+#define PCF8563_REG_SR 0x01 /*control-status register*/

static struct i2c_driver pcf8563_driver;

@@ -84,6 +87,9 @@ struct pcf8563 {
struct i2c_client *client;
#ifdef CONFIG_COMMON_CLK
struct clk_hw clkout_hw;
+const struct device *dev;
+const struct regmap *regmap;
+ bool suspended;
#endif
};

@@ -629,6 +635,7 @@ static int pcf8563_probe(struct i2c_client *client,
static const struct i2c_device_id pcf8563_id[] = {
{ "pcf8563", 0 },
{ "rtc8564", 0 },
+ { "pca8565", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, pcf8563_id);
@@ -636,11 +643,86 @@ MODULE_DEVICE_TABLE(i2c, pcf8563_id);
#ifdef CONFIG_OF
static const struct of_device_id pcf8563_of_match[] = {
{ .compatible = "nxp,pcf8563" },
+ { .compatible = "nxp,pca8565" },
{}
};
MODULE_DEVICE_TABLE(of, pcf8563_of_match);
#endif

+#if IS_ENABLED(CONFIG_SPI_MASTER)
+
+static int pca21125_probe(const struct spi_device *spi)
+{
+ int res;
+ unsigned int tmp;
+ static const struct regmap_config config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .write_flag_mask = 0x80,
+ };
+const struct regmap *regmap;
+const struct pcf8563 *pcf8563;
+
+ regmap = devm_regmap_init_spi(spi, &config);
+
+ if (IS_ERR(regmap)) {
+ dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
+ __func__, PTR_ERR(regmap));
+ return PTR_ERR(regmap);
+ }
+
+ spi->mode = SPI_MODE_3;
+ spi->bits_per_word = 8;
+ spi_setup(spi);
+
+ res = regmap_read(regmap, PCF8563_REG_SC, &tmp);
+
+ if (res)
+ return res;
+ res = regmap_read(regmap, PCF8563_REG_CLKO, &tmp);
+
+ if (res)
+ return res;
+
+ res = regmap_write(regmap, PCF8563_REG_CLKO, tmp & 0x1c);
+
+ if (res)
+ return res;
+
+ res = regmap_read(regmap, PCF8563_REG_SR, &tmp);
+
+ if (res)
+ return res;
+
+ res = regmap_write(regmap, PCF8563_REG_SR, tmp & 0x88);
+
+ if (res)
+ return res;
+
+ /* Print our settings */
+ res = regmap_read(regmap, PCF8563_REG_CLKO, &tmp);
+
+ if (res)
+ return res;
+
+ dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
+ res = regmap_read(regmap, PCF8563_REG_SR, &tmp);
+
+ if (res)
+ return res;
+
+ dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
+
+ pcf8563->rtc = devm_rtc_device_register(&spi->dev,
+ "pcf8563",
+ &pcf8563_rtc_ops, THIS_MODULE);
+}
+
+const struct spi_driver pca21125_driver = {
+ .driver = {
+ .name = "pca21125",
+ },
+
static struct i2c_driver pcf8563_driver = {
.driver = {
.name = "rtc-pcf8563",
--
1.9.2