diff mbox series

[3/8] rtc: make all reg_write callbacks take const void *

Message ID 20260715175229.24672-4-linkmauve@linkmauve.fr (mailing list archive)
State New
Headers
Series nvmem: make reg_write() take a const void * |

Commit Message

Link Mauve July 15, 2026, 5:52 p.m. UTC 
The previous commit switched from a pointer to mutable data to a pointer
to immutable data, so let’s fix all users of the nvmem_config API.

Signed-off-by: Link Mauve <linkmauve@linkmauve.fr>
---
 drivers/rtc/rtc-abx80x.c   | 4 ++--
 drivers/rtc/rtc-cmos.c     | 2 +-
 drivers/rtc/rtc-ds1305.c   | 4 ++--
 drivers/rtc/rtc-ds1307.c   | 2 +-
 drivers/rtc/rtc-ds1343.c   | 2 +-
 drivers/rtc/rtc-ds1511.c   | 2 +-
 drivers/rtc/rtc-ds1553.c   | 4 ++--
 drivers/rtc/rtc-ds1685.c   | 4 ++--
 drivers/rtc/rtc-ds1742.c   | 4 ++--
 drivers/rtc/rtc-ds3232.c   | 2 +-
 drivers/rtc/rtc-isl12026.c | 4 ++--
 drivers/rtc/rtc-isl1208.c  | 2 +-
 drivers/rtc/rtc-m48t59.c   | 4 ++--
 drivers/rtc/rtc-m48t86.c   | 2 +-
 drivers/rtc/rtc-max31335.c | 2 +-
 drivers/rtc/rtc-meson.c    | 2 +-
 drivers/rtc/rtc-omap.c     | 4 ++--
 drivers/rtc/rtc-pcf2127.c  | 2 +-
 drivers/rtc/rtc-pcf85063.c | 2 +-
 drivers/rtc/rtc-pcf85363.c | 4 ++--
 drivers/rtc/rtc-rp5c01.c   | 4 ++--
 drivers/rtc/rtc-rv3028.c   | 6 +++---
 drivers/rtc/rtc-rv3029c2.c | 2 +-
 drivers/rtc/rtc-rv3032.c   | 4 ++--
 drivers/rtc/rtc-rv8803.c   | 4 ++--
 drivers/rtc/rtc-rx8581.c   | 4 ++--
 drivers/rtc/rtc-s35390a.c  | 4 ++--
 drivers/rtc/rtc-stk17ta8.c | 4 ++--
 drivers/rtc/rtc-sun6i.c    | 4 ++--
 drivers/rtc/rtc-ti-k3.c    | 2 +-
 drivers/rtc/rtc-twl.c      | 2 +-
 31 files changed, 49 insertions(+), 49 deletions(-)

Comments

sashiko-bot@kernel.org July 15, 2026, 6:01 p.m. UTC | #1 
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Implicit pointer conversions discard the 'const' qualifier, causing compiler warnings.
--

--- Patch [3]: [PATCH 3/8] rtc: make all reg_write callbacks take const void * ---
commit dcceba66c45aeb1e0da5dfaf4cd7b3e0828ec69e
Author: Link Mauve <linkmauve@linkmauve.fr>

rtc: make all reg_write callbacks take const void *

This commit updates various RTC drivers to use a const void * parameter for
their nvmem_config write callbacks, aligning with the updated nvmem_config API.

> diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
> index fa04ece151b8b..09da71a0009e8 100644
> --- a/drivers/rtc/rtc-cmos.c
> +++ b/drivers/rtc/rtc-cmos.c
[ ... ]
> @@ -659,7 +659,7 @@ static int cmos_nvram_read(void *priv, unsigned int off, void *val,
>  	return 0;
>  }
>  
> -static int cmos_nvram_write(void *priv, unsigned int off, void *val,
> +static int cmos_nvram_write(void *priv, unsigned int off, const void *val,
>  			    size_t count)
>  {
>  	struct cmos_rtc	*cmos = priv;

[Severity: Low]
Does this cause a compiler warning for discarded qualifiers?

In the body of cmos_nvram_write(), the code assigns val to a non-const
pointer just below the diff context:

    unsigned char *buf = val;
    
Should buf also be declared as const unsigned char * to avoid breaking
builds where warnings are treated as errors?

> diff --git a/drivers/rtc/rtc-rv3032.c b/drivers/rtc/rtc-rv3032.c
> index 6bafdec637aea..b6b401be09bb5 100644
> --- a/drivers/rtc/rtc-rv3032.c
> +++ b/drivers/rtc/rtc-rv3032.c
[ ... ]
> @@ -493,7 +493,7 @@ static int rv3032_nvram_read(void *priv, unsigned int offset, void *val, size_t
>  	return regmap_bulk_read(priv, RV3032_RAM1 + offset, val, bytes);
>  }
>  
> -static int rv3032_eeprom_write(void *priv, unsigned int offset, void *val, size_t bytes)
> +static int rv3032_eeprom_write(void *priv, unsigned int offset, const void *val, size_t bytes)
>  {
>  	struct rv3032_data *rv3032 = priv;
>  	u32 status, eerd;

[Severity: Low]
Similar to the cmos driver, does this discard the const qualifier?

The rv3032_eeprom_write() function assigns the new const void *val to a 
non-const pointer just below the quoted diff context:

    u8 *buf = val;

Should this be updated to const u8 *buf as well?

> diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c
> index b72eef4fb0997..73ff0491f6750 100644
> --- a/drivers/rtc/rtc-s35390a.c
> +++ b/drivers/rtc/rtc-s35390a.c
[ ... ]
> @@ -67,7 +67,7 @@ struct s35390a {
>  	int twentyfourhour;
>  };
>  
> -static int s35390a_set_reg(struct s35390a *s35390a, int reg, u8  *buf, int len)
> +static int s35390a_set_reg(struct s35390a *s35390a, int reg, const u8 *buf, int len)
>  {
>  	struct i2c_client *client = s35390a->client[reg];
>  	struct i2c_msg msg[] = {

[Severity: Low]
Does this assignment in s35390a_set_reg() trigger a discarded qualifiers
warning?

The struct i2c_msg defines its buf member as __u8 * (non-const). When the
msg array is initialized just below this hunk:

    struct i2c_msg msg[] = {
        {
            .addr = client->addr,
            .len = len,
            .buf = buf
        },
    };

Will assigning the const u8 *buf to the non-const .buf field cause a compiler
warning? Would it be better to explicitly cast it like (u8 *)buf to satisfy
the i2c_msg struct definition?
diff mbox series

Patch

diff --git a/drivers/rtc/rtc-abx80x.c b/drivers/rtc/rtc-abx80x.c
index 5486d9d0b1e5..c401c70cbace 100644
--- a/drivers/rtc/rtc-abx80x.c
+++ b/drivers/rtc/rtc-abx80x.c
@@ -733,10 +733,10 @@  static int abx80x_nvmem_read(void *priv, unsigned int offset, void *val,
 	return abx80x_nvmem_xfer(priv, offset, val, bytes, false);
 }
 
-static int abx80x_nvmem_write(void *priv, unsigned int offset, void *val,
+static int abx80x_nvmem_write(void *priv, unsigned int offset, const void *val,
 			      size_t bytes)
 {
-	return abx80x_nvmem_xfer(priv, offset, val, bytes, true);
+	return abx80x_nvmem_xfer(priv, offset, (void *)val, bytes, true);
 }
 
 static int abx80x_setup_nvmem(struct abx80x_priv *priv)
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index fa04ece151b8..09da71a0009e 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -659,7 +659,7 @@  static int cmos_nvram_read(void *priv, unsigned int off, void *val,
 	return 0;
 }
 
-static int cmos_nvram_write(void *priv, unsigned int off, void *val,
+static int cmos_nvram_write(void *priv, unsigned int off, const void *val,
 			    size_t count)
 {
 	struct cmos_rtc	*cmos = priv;
diff --git a/drivers/rtc/rtc-ds1305.c b/drivers/rtc/rtc-ds1305.c
index d4de401548b4..eab61ec97ece 100644
--- a/drivers/rtc/rtc-ds1305.c
+++ b/drivers/rtc/rtc-ds1305.c
@@ -487,7 +487,7 @@  static irqreturn_t ds1305_irq(int irq, void *p)
  */
 
 static void msg_init(struct spi_message *m, struct spi_transfer *x,
-		u8 *addr, size_t count, char *tx, char *rx)
+		u8 *addr, size_t count, const char *tx, char *rx)
 {
 	spi_message_init(m);
 	memset(x, 0, 2 * sizeof(*x));
@@ -519,7 +519,7 @@  static int ds1305_nvram_read(void *priv, unsigned int off, void *buf,
 	return spi_sync(spi, &m);
 }
 
-static int ds1305_nvram_write(void *priv, unsigned int off, void *buf,
+static int ds1305_nvram_write(void *priv, unsigned int off, const void *buf,
 			      size_t count)
 {
 	struct ds1305		*ds1305 = priv;
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index fd3858b6569e..7cb6c96d2ec7 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -1285,7 +1285,7 @@  static int ds1307_nvram_read(void *priv, unsigned int offset, void *val,
 				val, bytes);
 }
 
-static int ds1307_nvram_write(void *priv, unsigned int offset, void *val,
+static int ds1307_nvram_write(void *priv, unsigned int offset, const void *val,
 			      size_t bytes)
 {
 	struct ds1307 *ds1307 = priv;
diff --git a/drivers/rtc/rtc-ds1343.c b/drivers/rtc/rtc-ds1343.c
index aa9500791b7e..b4daa5136078 100644
--- a/drivers/rtc/rtc-ds1343.c
+++ b/drivers/rtc/rtc-ds1343.c
@@ -123,7 +123,7 @@  static ssize_t ds1343_store_glitchfilter(struct device *dev,
 static DEVICE_ATTR(glitch_filter, S_IRUGO | S_IWUSR, ds1343_show_glitchfilter,
 			ds1343_store_glitchfilter);
 
-static int ds1343_nvram_write(void *priv, unsigned int off, void *val,
+static int ds1343_nvram_write(void *priv, unsigned int off, const void *val,
 			      size_t bytes)
 {
 	struct ds1343_priv *ds1343 = priv;
diff --git a/drivers/rtc/rtc-ds1511.c b/drivers/rtc/rtc-ds1511.c
index 8b087d9556be..23ee75f8035b 100644
--- a/drivers/rtc/rtc-ds1511.c
+++ b/drivers/rtc/rtc-ds1511.c
@@ -257,7 +257,7 @@  static int ds1511_nvram_read(void *priv, unsigned int pos, void *buf,
 	return 0;
 }
 
-static int ds1511_nvram_write(void *priv, unsigned int pos, void *buf,
+static int ds1511_nvram_write(void *priv, unsigned int pos, const void *buf,
 			      size_t size)
 {
 	int i;
diff --git a/drivers/rtc/rtc-ds1553.c b/drivers/rtc/rtc-ds1553.c
index dbff5b621ef5..d561bd5997bc 100644
--- a/drivers/rtc/rtc-ds1553.c
+++ b/drivers/rtc/rtc-ds1553.c
@@ -234,13 +234,13 @@  static int ds1553_nvram_read(void *priv, unsigned int pos, void *val,
 	return 0;
 }
 
-static int ds1553_nvram_write(void *priv, unsigned int pos, void *val,
+static int ds1553_nvram_write(void *priv, unsigned int pos, const void *val,
 			      size_t bytes)
 {
 	struct platform_device *pdev = priv;
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 	void __iomem *ioaddr = pdata->ioaddr;
-	u8 *buf = val;
+	const u8 *buf = val;
 
 	for (; bytes; bytes--)
 		writeb(*buf++, ioaddr + pos++);
diff --git a/drivers/rtc/rtc-ds1685.c b/drivers/rtc/rtc-ds1685.c
index 5fc8e36b1abf..996d13cd3ce3 100644
--- a/drivers/rtc/rtc-ds1685.c
+++ b/drivers/rtc/rtc-ds1685.c
@@ -904,13 +904,13 @@  static int ds1685_nvram_read(void *priv, unsigned int pos, void *val,
 	return 0;
 }
 
-static int ds1685_nvram_write(void *priv, unsigned int pos, void *val,
+static int ds1685_nvram_write(void *priv, unsigned int pos, const void *val,
 			      size_t size)
 {
 	struct ds1685_priv *rtc = priv;
 	struct mutex *rtc_mutex = &rtc->dev->ops_lock;
 	ssize_t count;
-	u8 *buf = val;
+	const u8 *buf = val;
 	int err;
 
 	err = mutex_lock_interruptible(rtc_mutex);
diff --git a/drivers/rtc/rtc-ds1742.c b/drivers/rtc/rtc-ds1742.c
index 6ae8b9a294fe..257d91400290 100644
--- a/drivers/rtc/rtc-ds1742.c
+++ b/drivers/rtc/rtc-ds1742.c
@@ -126,12 +126,12 @@  static int ds1742_nvram_read(void *priv, unsigned int pos, void *val,
 	return 0;
 }
 
-static int ds1742_nvram_write(void *priv, unsigned int pos, void *val,
+static int ds1742_nvram_write(void *priv, unsigned int pos, const void *val,
 			      size_t bytes)
 {
 	struct rtc_plat_data *pdata = priv;
 	void __iomem *ioaddr = pdata->ioaddr_nvram;
-	u8 *buf = val;
+	const u8 *buf = val;
 
 	for (; bytes; bytes--)
 		writeb(*buf++, ioaddr + pos++);
diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c
index d1ef9e0dad34..2a978c9f21b1 100644
--- a/drivers/rtc/rtc-ds3232.c
+++ b/drivers/rtc/rtc-ds3232.c
@@ -449,7 +449,7 @@  static int ds3232_nvmem_read(void *priv, unsigned int offset, void *val,
 				val, bytes);
 }
 
-static int ds3232_nvmem_write(void *priv, unsigned int offset, void *val,
+static int ds3232_nvmem_write(void *priv, unsigned int offset, const void *val,
 			      size_t bytes)
 {
 	struct regmap *ds3232_regmap = (struct regmap *)priv;
diff --git a/drivers/rtc/rtc-isl12026.c b/drivers/rtc/rtc-isl12026.c
index b86a325d8a23..0b8b1b50c7b6 100644
--- a/drivers/rtc/rtc-isl12026.c
+++ b/drivers/rtc/rtc-isl12026.c
@@ -319,11 +319,11 @@  static int isl12026_nvm_read(void *p, unsigned int offset,
 }
 
 static int isl12026_nvm_write(void *p, unsigned int offset,
-			      void *val, size_t bytes)
+			      const void *val, size_t bytes)
 {
 	struct isl12026 *priv = p;
 	int ret;
-	u8 *v = val;
+	const u8 *v = val;
 	size_t chunk_size, num_written;
 	u8 payload[ISL12026_PAGESIZE + 2]; /* page + 2 address bytes */
 	struct i2c_msg msgs[] = {
diff --git a/drivers/rtc/rtc-isl1208.c b/drivers/rtc/rtc-isl1208.c
index 9bdd5d121571..07ce522e69c5 100644
--- a/drivers/rtc/rtc-isl1208.c
+++ b/drivers/rtc/rtc-isl1208.c
@@ -799,7 +799,7 @@  static int isl1208_nvmem_read(void *priv, unsigned int off, void *buf,
 				    count);
 }
 
-static int isl1208_nvmem_write(void *priv, unsigned int off, void *buf,
+static int isl1208_nvmem_write(void *priv, unsigned int off, const void *buf,
 			       size_t count)
 {
 	struct isl1208_state *isl1208 = priv;
diff --git a/drivers/rtc/rtc-m48t59.c b/drivers/rtc/rtc-m48t59.c
index 4e608bc8bbd3..ad407faecf1f 100644
--- a/drivers/rtc/rtc-m48t59.c
+++ b/drivers/rtc/rtc-m48t59.c
@@ -316,7 +316,7 @@  static int m48t59_nvram_read(void *priv, unsigned int offset, void *val,
 	return 0;
 }
 
-static int m48t59_nvram_write(void *priv, unsigned int offset, void *val,
+static int m48t59_nvram_write(void *priv, unsigned int offset, const void *val,
 			      size_t size)
 {
 	struct platform_device *pdev = priv;
@@ -325,7 +325,7 @@  static int m48t59_nvram_write(void *priv, unsigned int offset, void *val,
 	struct m48t59_private *m48t59 = platform_get_drvdata(pdev);
 	ssize_t cnt = 0;
 	unsigned long flags;
-	u8 *buf = val;
+	const u8 *buf = val;
 
 	spin_lock_irqsave(&m48t59->lock, flags);
 
diff --git a/drivers/rtc/rtc-m48t86.c b/drivers/rtc/rtc-m48t86.c
index db3bdb171ff0..da3835d85fbc 100644
--- a/drivers/rtc/rtc-m48t86.c
+++ b/drivers/rtc/rtc-m48t86.c
@@ -171,7 +171,7 @@  static int m48t86_nvram_read(void *priv, unsigned int off, void *buf,
 	return 0;
 }
 
-static int m48t86_nvram_write(void *priv, unsigned int off, void *buf,
+static int m48t86_nvram_write(void *priv, unsigned int off, const void *buf,
 			      size_t count)
 {
 	struct device *dev = priv;
diff --git a/drivers/rtc/rtc-max31335.c b/drivers/rtc/rtc-max31335.c
index 595816973851..3b3d4b0d3af3 100644
--- a/drivers/rtc/rtc-max31335.c
+++ b/drivers/rtc/rtc-max31335.c
@@ -576,7 +576,7 @@  static int max31335_nvmem_reg_read(void *priv, unsigned int offset,
 }
 
 static int max31335_nvmem_reg_write(void *priv, unsigned int offset,
-				    void *val, size_t bytes)
+				    const void *val, size_t bytes)
 {
 	struct max31335_data *max31335 = priv;
 	unsigned int reg = max31335->chip->ram_reg + offset;
diff --git a/drivers/rtc/rtc-meson.c b/drivers/rtc/rtc-meson.c
index 21eceb9e2e13..d9dbab95e5da 100644
--- a/drivers/rtc/rtc-meson.c
+++ b/drivers/rtc/rtc-meson.c
@@ -266,7 +266,7 @@  static int meson_rtc_regmem_read(void *context, unsigned int offset,
 }
 
 static int meson_rtc_regmem_write(void *context, unsigned int offset,
-				  void *buf, size_t bytes)
+				  const void *buf, size_t bytes)
 {
 	struct meson_rtc *rtc = context;
 	unsigned int write_offset, write_size;
diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index 0f90065e352c..63a555697ddf 100644
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -699,11 +699,11 @@  static int omap_rtc_scratch_read(void *priv, unsigned int offset, void *_val,
 	return 0;
 }
 
-static int omap_rtc_scratch_write(void *priv, unsigned int offset, void *_val,
+static int omap_rtc_scratch_write(void *priv, unsigned int offset, const void *_val,
 				  size_t bytes)
 {
 	struct omap_rtc	*rtc = priv;
-	u32 *val = _val;
+	const u32 *val = _val;
 	int i;
 
 	rtc->type->unlock(rtc);
diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 1995e9f2756d..77b1a4a6a8b5 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -460,7 +460,7 @@  static int pcf2127_nvmem_read(void *priv, unsigned int offset,
 }
 
 static int pcf2127_nvmem_write(void *priv, unsigned int offset,
-			       void *val, size_t bytes)
+			       const void *val, size_t bytes)
 {
 	struct pcf2127 *pcf2127 = priv;
 	int ret;
diff --git a/drivers/rtc/rtc-pcf85063.c b/drivers/rtc/rtc-pcf85063.c
index 01e209d88f5f..7cb59a105b5d 100644
--- a/drivers/rtc/rtc-pcf85063.c
+++ b/drivers/rtc/rtc-pcf85063.c
@@ -340,7 +340,7 @@  static int pcf85063_nvmem_read(void *priv, unsigned int offset,
 }
 
 static int pcf85063_nvmem_write(void *priv, unsigned int offset,
-				void *val, size_t bytes)
+				const void *val, size_t bytes)
 {
 	return regmap_write(priv, PCF85063_REG_RAM, *(u8 *)val);
 }
diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
index 540042b9eec8..d652a9353fd6 100644
--- a/drivers/rtc/rtc-pcf85363.c
+++ b/drivers/rtc/rtc-pcf85363.c
@@ -328,7 +328,7 @@  static int pcf85363_nvram_read(void *priv, unsigned int offset, void *val,
 				val, bytes);
 }
 
-static int pcf85363_nvram_write(void *priv, unsigned int offset, void *val,
+static int pcf85363_nvram_write(void *priv, unsigned int offset, const void *val,
 				size_t bytes)
 {
 	struct pcf85363 *pcf85363 = priv;
@@ -350,7 +350,7 @@  static int pcf85x63_nvram_read(void *priv, unsigned int offset, void *val,
 	return ret;
 }
 
-static int pcf85x63_nvram_write(void *priv, unsigned int offset, void *val,
+static int pcf85x63_nvram_write(void *priv, unsigned int offset, const void *val,
 				size_t bytes)
 {
 	struct pcf85363 *pcf85363 = priv;
diff --git a/drivers/rtc/rtc-rp5c01.c b/drivers/rtc/rtc-rp5c01.c
index 44afa6d996e7..b38799525043 100644
--- a/drivers/rtc/rtc-rp5c01.c
+++ b/drivers/rtc/rtc-rp5c01.c
@@ -188,11 +188,11 @@  static int rp5c01_nvram_read(void *_priv, unsigned int pos, void *val,
 	return 0;
 }
 
-static int rp5c01_nvram_write(void *_priv, unsigned int pos, void *val,
+static int rp5c01_nvram_write(void *_priv, unsigned int pos, const void *val,
 			      size_t bytes)
 {
 	struct rp5c01_priv *priv = _priv;
-	u8 *buf = val;
+	const u8 *buf = val;
 
 	spin_lock_irq(&priv->lock);
 
diff --git a/drivers/rtc/rtc-rv3028.c b/drivers/rtc/rtc-rv3028.c
index d96f6bb68850..e95600493f7f 100644
--- a/drivers/rtc/rtc-rv3028.c
+++ b/drivers/rtc/rtc-rv3028.c
@@ -602,7 +602,7 @@  static int rv3028_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 	}
 }
 
-static int rv3028_nvram_write(void *priv, unsigned int offset, void *val,
+static int rv3028_nvram_write(void *priv, unsigned int offset, const void *val,
 			      size_t bytes)
 {
 	return regmap_bulk_write(priv, RV3028_RAM1 + offset, val, bytes);
@@ -614,13 +614,13 @@  static int rv3028_nvram_read(void *priv, unsigned int offset, void *val,
 	return regmap_bulk_read(priv, RV3028_RAM1 + offset, val, bytes);
 }
 
-static int rv3028_eeprom_write(void *priv, unsigned int offset, void *val,
+static int rv3028_eeprom_write(void *priv, unsigned int offset, const void *val,
 			       size_t bytes)
 {
 	struct rv3028_data *rv3028 = priv;
 	u32 status, eerd;
 	int i, ret;
-	u8 *buf = val;
+	const u8 *buf = val;
 
 	ret = rv3028_enter_eerd(rv3028, &eerd);
 	if (ret)
diff --git a/drivers/rtc/rtc-rv3029c2.c b/drivers/rtc/rtc-rv3029c2.c
index 98953af2a24a..a6a01e0c5d9d 100644
--- a/drivers/rtc/rtc-rv3029c2.c
+++ b/drivers/rtc/rtc-rv3029c2.c
@@ -472,7 +472,7 @@  static int rv3029_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 	}
 }
 
-static int rv3029_nvram_write(void *priv, unsigned int offset, void *val,
+static int rv3029_nvram_write(void *priv, unsigned int offset, const void *val,
 			      size_t bytes)
 {
 	return regmap_bulk_write(priv, RV3029_RAM_PAGE + offset, val, bytes);
diff --git a/drivers/rtc/rtc-rv3032.c b/drivers/rtc/rtc-rv3032.c
index 6bafdec637ae..b6b401be09bb 100644
--- a/drivers/rtc/rtc-rv3032.c
+++ b/drivers/rtc/rtc-rv3032.c
@@ -483,7 +483,7 @@  static int rv3032_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 	}
 }
 
-static int rv3032_nvram_write(void *priv, unsigned int offset, void *val, size_t bytes)
+static int rv3032_nvram_write(void *priv, unsigned int offset, const void *val, size_t bytes)
 {
 	return regmap_bulk_write(priv, RV3032_RAM1 + offset, val, bytes);
 }
@@ -493,7 +493,7 @@  static int rv3032_nvram_read(void *priv, unsigned int offset, void *val, size_t
 	return regmap_bulk_read(priv, RV3032_RAM1 + offset, val, bytes);
 }
 
-static int rv3032_eeprom_write(void *priv, unsigned int offset, void *val, size_t bytes)
+static int rv3032_eeprom_write(void *priv, unsigned int offset, const void *val, size_t bytes)
 {
 	struct rv3032_data *rv3032 = priv;
 	u32 status, eerd;
diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c
index b9b5fee16ee4..f2adccf611dd 100644
--- a/drivers/rtc/rtc-rv8803.c
+++ b/drivers/rtc/rtc-rv8803.c
@@ -536,10 +536,10 @@  static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 	}
 }
 
-static int rv8803_nvram_write(void *priv, unsigned int offset, void *val,
+static int rv8803_nvram_write(void *priv, unsigned int offset, const void *val,
 			      size_t bytes)
 {
-	return rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val);
+	return rv8803_write_reg(priv, RV8803_RAM, *(const u8 *)val);
 }
 
 static int rv8803_nvram_read(void *priv, unsigned int offset,
diff --git a/drivers/rtc/rtc-rx8581.c b/drivers/rtc/rtc-rx8581.c
index cf4dab94c337..6da6219ed8fe 100644
--- a/drivers/rtc/rtc-rx8581.c
+++ b/drivers/rtc/rtc-rx8581.c
@@ -188,7 +188,7 @@  static int rx8571_nvram_read(void *priv, unsigned int offset, void *val,
 	return regmap_bulk_read(regmap, RX8571_USER_RAM + offset, val, bytes);
 }
 
-static int rx8571_nvram_write(void *priv, unsigned int offset, void *val,
+static int rx8571_nvram_write(void *priv, unsigned int offset, const void *val,
 			      size_t bytes)
 {
 	struct regmap *regmap = priv;
@@ -209,7 +209,7 @@  static int rx85x1_nvram_read(void *priv, unsigned int offset, void *val,
 	return ret;
 }
 
-static int rx85x1_nvram_write(void *priv, unsigned int offset, void *val,
+static int rx85x1_nvram_write(void *priv, unsigned int offset, const void *val,
 			      size_t bytes)
 {
 	struct regmap *regmap = priv;
diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c
index b72eef4fb099..73ff0491f675 100644
--- a/drivers/rtc/rtc-s35390a.c
+++ b/drivers/rtc/rtc-s35390a.c
@@ -67,7 +67,7 @@  struct s35390a {
 	int twentyfourhour;
 };
 
-static int s35390a_set_reg(struct s35390a *s35390a, int reg, u8  *buf, int len)
+static int s35390a_set_reg(struct s35390a *s35390a, int reg, const u8 *buf, int len)
 {
 	struct i2c_client *client = s35390a->client[reg];
 	struct i2c_msg msg[] = {
@@ -426,7 +426,7 @@  static int s35390a_nvmem_read(void *priv, unsigned int offset, void *val,
 	return s35390a_get_reg(s35390a, S35390A_CMD_FREE_REG, val, bytes);
 }
 
-static int s35390a_nvmem_write(void *priv, unsigned int offset, void *val,
+static int s35390a_nvmem_write(void *priv, unsigned int offset, const void *val,
 			       size_t bytes)
 {
 	struct s35390a *s35390a = priv;
diff --git a/drivers/rtc/rtc-stk17ta8.c b/drivers/rtc/rtc-stk17ta8.c
index 7cb6be1b7815..c667be6829d6 100644
--- a/drivers/rtc/rtc-stk17ta8.c
+++ b/drivers/rtc/rtc-stk17ta8.c
@@ -242,12 +242,12 @@  static int stk17ta8_nvram_read(void *priv, unsigned int pos, void *val,
 	return 0;
 }
 
-static int stk17ta8_nvram_write(void *priv, unsigned int pos, void *val,
+static int stk17ta8_nvram_write(void *priv, unsigned int pos, const void *val,
 				size_t bytes)
 {
 	struct rtc_plat_data *pdata = priv;
 	void __iomem *ioaddr = pdata->ioaddr;
-	u8 *buf = val;
+	const u8 *buf = val;
 
 	for (; bytes; bytes--)
 		writeb(*buf++, ioaddr + pos++);
diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c
index 7fc60880e409..67af5198f815 100644
--- a/drivers/rtc/rtc-sun6i.c
+++ b/drivers/rtc/rtc-sun6i.c
@@ -688,10 +688,10 @@  static int sun6i_rtc_nvmem_read(void *priv, unsigned int offset, void *_val, siz
 	return 0;
 }
 
-static int sun6i_rtc_nvmem_write(void *priv, unsigned int offset, void *_val, size_t bytes)
+static int sun6i_rtc_nvmem_write(void *priv, unsigned int offset, const void *_val, size_t bytes)
 {
 	struct sun6i_rtc_dev *chip = priv;
-	u32 *val = _val;
+	const u32 *val = _val;
 	int i;
 
 	for (i = 0; i < bytes / 4; ++i)
diff --git a/drivers/rtc/rtc-ti-k3.c b/drivers/rtc/rtc-ti-k3.c
index 8df00319cb6b..03b7a7fe631e 100644
--- a/drivers/rtc/rtc-ti-k3.c
+++ b/drivers/rtc/rtc-ti-k3.c
@@ -491,7 +491,7 @@  static int ti_k3_rtc_scratch_read(void *priv_data, unsigned int offset,
 }
 
 static int ti_k3_rtc_scratch_write(void *priv_data, unsigned int offset,
-				   void *val, size_t bytes)
+				   const void *val, size_t bytes)
 {
 	struct ti_k3_rtc *priv = (struct ti_k3_rtc *)priv_data;
 	int ret;
diff --git a/drivers/rtc/rtc-twl.c b/drivers/rtc/rtc-twl.c
index e6106e67e1f4..6b5dc1f09884 100644
--- a/drivers/rtc/rtc-twl.c
+++ b/drivers/rtc/rtc-twl.c
@@ -493,7 +493,7 @@  static int twl_nvram_read(void *priv, unsigned int offset, void *val,
 	return twl_i2c_read((long)priv, val, offset, bytes);
 }
 
-static int twl_nvram_write(void *priv, unsigned int offset, void *val,
+static int twl_nvram_write(void *priv, unsigned int offset, const void *val,
 			   size_t bytes)
 {
 	return twl_i2c_write((long)priv, val, offset, bytes);