[cip-dev] [PATCH 4.19.y-cip 4/6] rtc: rx8581: Add support for Epson rx8571 RTC

Biju Das
2019-07-15T14:17:23Z

commit 51f896ffd1a5aacbda82ed82552c4077e3cc3b68 upstream.

Add support for Epson rx8571 real-time clock. rx8571 rtc is compatible
with rx8581,except that rx8571 has additional 16 bytes of RAM.

16 bytes of nvmem is supported and exposed in sysfs (# is the instance
number,starting with 0): /sys/bus/nvmem/devices/rx8571-#/nvmem

Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
drivers/rtc/Kconfig | 5 ++-
drivers/rtc/rtc-rx8581.c | 114 +++++++++++++++++++++++++++++++++++++++++++----
2 files changed, 108 insertions(+), 11 deletions(-)

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 7d7be60..ec2cba4 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -600,9 +600,10 @@ config RTC_DRV_RX8010
will be called rtc-rx8010.

config RTC_DRV_RX8581
- tristate "Epson RX-8581"
+ tristate "Epson RX-8571/RX-8581"
help
- If you say yes here you will get support for the Epson RX-8581.
+ If you say yes here you will get support for the Epson RX-8571/
+ RX-8581.

This driver can also be built as a module. If so the module
will be called rtc-rx8581.
diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
index eac8821..776e3a2 100644
--- a/drivers/rtc/rtc-rx8581.c
+++ b/drivers/rtc/rtc-rx8581.c
@@ -15,6 +15,8 @@
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/bcd.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/log2.h>
@@ -51,11 +53,19 @@
#define RX8581_CTRL_STOP 0x02 /* STOP bit */
#define RX8581_CTRL_RESET 0x01 /* RESET bit */

+#define RX8571_USER_RAM 0x10
+#define RX8571_NVRAM_SIZE 0x10
+
struct rx8581 {
struct regmap *regmap;
struct rtc_device *rtc;
};

+struct rx85x1_config {
+ struct regmap_config regmap;
+ unsigned int num_nvram;
+};
+
/*
* In the routines that deal directly with the rx8581 hardware, we use
* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
@@ -181,25 +191,103 @@ static const struct rtc_class_ops rx8581_rtc_ops = {
.set_time = rx8581_rtc_set_time,
};

-static int rx8581_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
+static int rx8571_nvram_read(void *priv, unsigned int offset, void *val,
+ size_t bytes)
{
- struct rx8581 *rx8581;
- static const struct regmap_config config = {
+ struct rx8581 *rx8581 = priv;
+
+ return regmap_bulk_read(rx8581->regmap, RX8571_USER_RAM + offset,
+ val, bytes);
+}
+
+static int rx8571_nvram_write(void *priv, unsigned int offset, void *val,
+ size_t bytes)
+{
+ struct rx8581 *rx8581 = priv;
+
+ return regmap_bulk_write(rx8581->regmap, RX8571_USER_RAM + offset,
+ val, bytes);
+}
+
+static int rx85x1_nvram_read(void *priv, unsigned int offset, void *val,
+ size_t bytes)
+{
+ struct rx8581 *rx8581 = priv;
+ unsigned int tmp_val;
+ int ret;
+
+ ret = regmap_read(rx8581->regmap, RX8581_REG_RAM, &tmp_val);
+ (*(unsigned char *)val) = (unsigned char) tmp_val;
+
+ return ret;
+}
+
+static int rx85x1_nvram_write(void *priv, unsigned int offset, void *val,
+ size_t bytes)
+{
+ struct rx8581 *rx8581 = priv;
+ unsigned char tmp_val;
+
+ tmp_val = *((unsigned char *)val);
+ return regmap_write(rx8581->regmap, RX8581_REG_RAM,
+ (unsigned int)tmp_val);
+}
+
+static const struct rx85x1_config rx8581_config = {
+ .regmap = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0xf,
+ },
+ .num_nvram = 1
+};
+
+static const struct rx85x1_config rx8571_config = {
+ .regmap = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = 0x1f,
+ },
+ .num_nvram = 2
+};
+
+static int rx8581_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct rx8581 *rx8581;
+ const struct rx85x1_config *config = &rx8581_config;
+ const void *data = of_device_get_match_data(&client->dev);
+ static struct nvmem_config nvmem_cfg[] = {
+ {
+ .name = "rx85x1-",
+ .word_size = 1,
+ .stride = 1,
+ .size = 1,
+ .reg_read = rx85x1_nvram_read,
+ .reg_write = rx85x1_nvram_write,
+ }, {
+ .name = "rx8571-",
+ .word_size = 1,
+ .stride = 1,
+ .size = RX8571_NVRAM_SIZE,
+ .reg_read = rx8571_nvram_read,
+ .reg_write = rx8571_nvram_write,
+ },
};
+ int ret, i;

dev_dbg(&client->dev, "%s\n", __func__);

+ if (data)
+ config = data;
+
rx8581 = devm_kzalloc(&client->dev, sizeof(struct rx8581), GFP_KERNEL);
if (!rx8581)
return -ENOMEM;

i2c_set_clientdata(client, rx8581);

- rx8581->regmap = devm_regmap_init_i2c(client, &config);
+ rx8581->regmap = devm_regmap_init_i2c(client, &config->regmap);
if (IS_ERR(rx8581->regmap))
return PTR_ERR(rx8581->regmap);

@@ -213,7 +301,14 @@ static int rx8581_probe(struct i2c_client *client,
rx8581->rtc->start_secs = 0;
rx8581->rtc->set_start_time = true;

- return rtc_register_device(rx8581->rtc);
+ ret = rtc_register_device(rx8581->rtc);
+
+ for (i = 0; i < config->num_nvram; i++) {
+ nvmem_cfg[i].priv = rx8581;
+ rtc_nvmem_register(rx8581->rtc, &nvmem_cfg[i]);
+ }
+
+ return ret;
}

static const struct i2c_device_id rx8581_id[] = {
@@ -223,8 +318,9 @@ static const struct i2c_device_id rx8581_id[] = {
MODULE_DEVICE_TABLE(i2c, rx8581_id);

static const struct of_device_id rx8581_of_match[] = {
- { .compatible = "epson,rx8581" },
- { }
+ { .compatible = "epson,rx8571", .data = &rx8571_config },
+ { .compatible = "epson,rx8581", .data = &rx8581_config },
+ { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rx8581_of_match);

@@ -240,5 +336,5 @@ static struct i2c_driver rx8581_driver = {
module_i2c_driver(rx8581_driver);

MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
-MODULE_DESCRIPTION("Epson RX-8581 RTC driver");
+MODULE_DESCRIPTION("Epson RX-8571/RX-8581 RTC driver");
MODULE_LICENSE("GPL");
--
2.7.4