2020-08-17 18:31:04

by Min Li

Subject: [PATCH net] ptp: ptp_clockmatrix: use i2c_master_send for i2c write

From: Min Li <[email protected]>

The old code for i2c write would break on some controllers, which fails
at handling Repeated Start Condition. So we will just use i2c_master_send
to handle write in one transanction.

Signed-off-by: Min Li <[email protected]>
---
drivers/ptp/ptp_clockmatrix.c | 56 +++++++++++++++++++++++++++++++++----------
drivers/ptp/ptp_clockmatrix.h | 4 +++-
2 files changed, 46 insertions(+), 14 deletions(-)

diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c
index 73aaae5..e020faf 100644
--- a/drivers/ptp/ptp_clockmatrix.c
+++ b/drivers/ptp/ptp_clockmatrix.c
@@ -142,16 +142,15 @@ static int idtcm_strverscmp(const char *ver1, const char *ver2)
return result;
}

-static int idtcm_xfer(struct idtcm *idtcm,
- u8 regaddr,
- u8 *buf,
- u16 count,
- bool write)
+static int idtcm_xfer_read(struct idtcm *idtcm,
+ u8 regaddr,
+ u8 *buf,
+ u16 count)
{
struct i2c_client *client = idtcm->client;
struct i2c_msg msg[2];
int cnt;
- char *fmt = "i2c_transfer failed at %d in %s for %s, at addr: %04X!\n";
+ char *fmt = "i2c_transfer failed at %d in %s, at addr: %04X!\n";

msg[0].addr = client->addr;
msg[0].flags = 0;
@@ -159,7 +158,7 @@ static int idtcm_xfer(struct idtcm *idtcm,
msg[0].buf = &regaddr;

msg[1].addr = client->addr;
- msg[1].flags = write ? 0 : I2C_M_RD;
+ msg[1].flags = I2C_M_RD;
msg[1].len = count;
msg[1].buf = buf;

@@ -170,7 +169,6 @@ static int idtcm_xfer(struct idtcm *idtcm,
fmt,
__LINE__,
__func__,
- write ? "write" : "read",
regaddr);
return cnt;
} else if (cnt != 2) {
@@ -182,6 +180,37 @@ static int idtcm_xfer(struct idtcm *idtcm,
return 0;
}

+static int idtcm_xfer_write(struct idtcm *idtcm,
+ u8 regaddr,
+ u8 *buf,
+ u16 count)
+{
+ struct i2c_client *client = idtcm->client;
+ /* we add 1 byte for device register */
+ u8 msg[IDTCM_MAX_WRITE_COUNT + 1];
+ int cnt;
+ char *fmt = "i2c_master_send failed at %d in %s, at addr: %04X!\n";
+
+ if (count > IDTCM_MAX_WRITE_COUNT)
+ return -EINVAL;
+
+ msg[0] = regaddr;
+ memcpy(&msg[1], buf, count);
+
+ cnt = i2c_master_send(client, msg, count + 1);
+
+ if (cnt < 0) {
+ dev_err(&client->dev,
+ fmt,
+ __LINE__,
+ __func__,
+ regaddr);
+ return cnt;
+ }
+
+ return 0;
+}
+
static int idtcm_page_offset(struct idtcm *idtcm, u8 val)
{
u8 buf[4];
@@ -195,7 +224,7 @@ static int idtcm_page_offset(struct idtcm *idtcm, u8 val)
buf[2] = 0x10;
buf[3] = 0x20;

- err = idtcm_xfer(idtcm, PAGE_ADDR, buf, sizeof(buf), 1);
+ err = idtcm_xfer_write(idtcm, PAGE_ADDR, buf, sizeof(buf));

if (err) {
idtcm->page_offset = 0xff;
@@ -223,11 +252,12 @@ static int _idtcm_rdwr(struct idtcm *idtcm,
err = idtcm_page_offset(idtcm, hi);

if (err)
- goto out;
+ return err;

- err = idtcm_xfer(idtcm, lo, buf, count, write);
-out:
- return err;
+ if (write)
+ return idtcm_xfer_write(idtcm, lo, buf, count);
+
+ return idtcm_xfer_read(idtcm, lo, buf, count);
}

static int idtcm_read(struct idtcm *idtcm,
diff --git a/drivers/ptp/ptp_clockmatrix.h b/drivers/ptp/ptp_clockmatrix.h
index ffae56c..344aa04 100644
--- a/drivers/ptp/ptp_clockmatrix.h
+++ b/drivers/ptp/ptp_clockmatrix.h
@@ -53,7 +53,9 @@

#define OUTPUT_MODULE_FROM_INDEX(index) (OUTPUT_0 + (index) * 0x10)

-#define PEROUT_ENABLE_OUTPUT_MASK (0xdeadbeef)
+#define PEROUT_ENABLE_OUTPUT_MASK (0xdeadbeef)
+
+#define IDTCM_MAX_WRITE_COUNT (512)

/* Values of DPLL_N.DPLL_MODE.PLL_MODE */
enum pll_mode {
--
2.7.4

2020-08-17 23:12:55

by David Miller

Subject: Re: [PATCH net] ptp: ptp_clockmatrix: use i2c_master_send for i2c write

From: <[email protected]>
Date: Mon, 17 Aug 2020 11:37:35 -0400

> @@ -53,7 +53,9 @@
>
> #define OUTPUT_MODULE_FROM_INDEX(index) (OUTPUT_0 + (index) * 0x10)
>
> -#define PEROUT_ENABLE_OUTPUT_MASK (0xdeadbeef)
> +#define PEROUT_ENABLE_OUTPUT_MASK (0xdeadbeef)
> +
> +#define IDTCM_MAX_WRITE_COUNT (512)

Why adjust the indentation of the value of PEROUT_ENABLE_OUTPUT_MASK? It is meant
to line up with OUTPUT_MODULE_FROM_INDEX.

Please do not make unrelated changes like this and follow existing style and
indentation.

Thank you.