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author | Biju Das <biju.das.jz@bp.renesas.com> | 2023-06-23 15:09:47 +0100 |
---|---|---|
committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2023-06-26 00:58:21 +0200 |
commit | 262f72b4656e182eefaab91ab24a7575dda5524f (patch) | |
tree | 8a520a34c8ef1ef9d8ec5dc28c7b9ff52ed76828 /drivers/rtc | |
parent | 5923fc75d0dfcebce53894ddada7e2440d756f8b (diff) | |
download | linux-262f72b4656e182eefaab91ab24a7575dda5524f.tar.gz linux-262f72b4656e182eefaab91ab24a7575dda5524f.tar.bz2 linux-262f72b4656e182eefaab91ab24a7575dda5524f.zip |
rtc: isl1208: Add isl1208_set_xtoscb()
As per the HW manual, set the XTOSCB bit as follows:
If using an external clock signal, set the XTOSCB bit as 1 to
disable the crystal oscillator.
If using an external crystal, the XTOSCB bit needs to be set at 0
to enable the crystal oscillator.
Add isl1208_set_xtoscb() to set XTOSCB bit based on the clock-names
property. Fallback is enabling the internal crystal oscillator.
While at it, introduce a variable "sr" for reading the status register
in probe() as it is reused for writing and also remove the unnecessary
blank line.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230623140948.384762-10-biju.das.jz@bp.renesas.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc')
-rw-r--r-- | drivers/rtc/rtc-isl1208.c | 57 |
1 files changed, 51 insertions, 6 deletions
diff --git a/drivers/rtc/rtc-isl1208.c b/drivers/rtc/rtc-isl1208.c index 42d2116d244d..e9ec5675e27c 100644 --- a/drivers/rtc/rtc-isl1208.c +++ b/drivers/rtc/rtc-isl1208.c @@ -6,6 +6,7 @@ */ #include <linux/bcd.h> +#include <linux/clk.h> #include <linux/i2c.h> #include <linux/module.h> #include <linux/of_device.h> @@ -175,6 +176,20 @@ isl1208_i2c_validate_client(struct i2c_client *client) return 0; } +static int isl1208_set_xtoscb(struct i2c_client *client, int sr, int xtosb_val) +{ + /* Do nothing if bit is already set to desired value */ + if ((sr & ISL1208_REG_SR_XTOSCB) == xtosb_val) + return 0; + + if (xtosb_val) + sr |= ISL1208_REG_SR_XTOSCB; + else + sr &= ~ISL1208_REG_SR_XTOSCB; + + return i2c_smbus_write_byte_data(client, ISL1208_REG_SR, sr); +} + static int isl1208_i2c_get_sr(struct i2c_client *client) { @@ -511,7 +526,6 @@ isl1208_i2c_set_time(struct i2c_client *client, struct rtc_time const *tm) return 0; } - static int isl1208_rtc_set_time(struct device *dev, struct rtc_time *tm) { @@ -806,11 +820,25 @@ static int isl1208_setup_irq(struct i2c_client *client, int irq) } static int +isl1208_clk_present(struct i2c_client *client, const char *name) +{ + struct clk *clk; + + clk = devm_clk_get_optional(&client->dev, name); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + return !!clk; +} + +static int isl1208_probe(struct i2c_client *client) { - int rc = 0; struct isl1208_state *isl1208; int evdet_irq = -1; + int xtosb_val = 0; + int rc = 0; + int sr; if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) return -ENODEV; @@ -837,6 +865,19 @@ isl1208_probe(struct i2c_client *client) isl1208->config = (struct isl1208_config *)id->driver_data; } + rc = isl1208_clk_present(client, "xin"); + if (rc < 0) + return rc; + + if (!rc) { + rc = isl1208_clk_present(client, "clkin"); + if (rc < 0) + return rc; + + if (rc) + xtosb_val = 1; + } + isl1208->rtc = devm_rtc_allocate_device(&client->dev); if (IS_ERR(isl1208->rtc)) return PTR_ERR(isl1208->rtc); @@ -848,13 +889,17 @@ isl1208_probe(struct i2c_client *client) isl1208->nvmem_config.size = isl1208->config->nvmem_length; isl1208->nvmem_config.priv = isl1208; - rc = isl1208_i2c_get_sr(client); - if (rc < 0) { + sr = isl1208_i2c_get_sr(client); + if (sr < 0) { dev_err(&client->dev, "reading status failed\n"); - return rc; + return sr; } - if (rc & ISL1208_REG_SR_RTCF) + rc = isl1208_set_xtoscb(client, sr, xtosb_val); + if (rc) + return rc; + + if (sr & ISL1208_REG_SR_RTCF) dev_warn(&client->dev, "rtc power failure detected, " "please set clock.\n"); |