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To:     Antti Palosaari <crope@iki.fi>,
        Mauro Carvalho Chehab <mchehab@kernel.org>
Cc:     linux-media <linux-media@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        =?UTF-8?Q?Jonathan_Neusch=c3=a4fer?= <j.neuschaefer@gmx.net>,
        Bjorn Andersson <bjorn.andersson@linaro.org>,
        Brad Love <brad@nextdimension.cc>
From:   Marc Gonzalez <marc.w.gonzalez@free.fr>
Subject: [PATCH v1] media: si2168: Refactor command setup code
Message-ID: <6a8f9a5b-2e88-8c26-440b-76af0d91eda6@free.fr>
Date:   Mon, 1 Jul 2019 13:44:09 +0200
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Sender: linux-kernel-owner@vger.kernel.org
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By refactoring the command setup code, we can let the compiler
determine the size of each command.

Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
---
 drivers/media/dvb-frontends/si2168.c | 142 ++++++++-------------------
 1 file changed, 41 insertions(+), 101 deletions(-)

diff --git a/drivers/media/dvb-frontends/si2168.c b/drivers/media/dvb-frontends/si2168.c
index 168c503e9154..19398f041c79 100644
--- a/drivers/media/dvb-frontends/si2168.c
+++ b/drivers/media/dvb-frontends/si2168.c
@@ -11,6 +11,12 @@
 
 static const struct dvb_frontend_ops si2168_ops;
 
+#define CMD_SETUP(cmd, __args, __rlen) do {	\
+	int wlen = sizeof(__args) - 1;		\
+	memcpy(cmd.args, __args, wlen);		\
+	cmd.wlen = wlen; cmd.rlen = __rlen;	\
+} while (0)
+
 /* execute firmware command */
 static int si2168_cmd_execute(struct i2c_client *client, struct si2168_cmd *cmd)
 {
@@ -83,15 +89,13 @@ static int si2168_ts_bus_ctrl(struct dvb_frontend *fe, int acquire)
 	dev_dbg(&client->dev, "%s acquire: %d\n", __func__, acquire);
 
 	/* set TS_MODE property */
-	memcpy(cmd.args, "\x14\x00\x01\x10\x10\x00", 6);
+	CMD_SETUP(cmd, "\x14\x00\x01\x10\x10\x00", 4);
 	if (acquire)
 		cmd.args[4] |= dev->ts_mode;
 	else
 		cmd.args[4] |= SI2168_TS_TRISTATE;
 	if (dev->ts_clock_gapped)
 		cmd.args[4] |= 0x40;
-	cmd.wlen = 6;
-	cmd.rlen = 4;
 	ret = si2168_cmd_execute(client, &cmd);
 
 	return ret;
@@ -115,19 +119,13 @@ static int si2168_read_status(struct dvb_frontend *fe, enum fe_status *status)
 
 	switch (c->delivery_system) {
 	case SYS_DVBT:
-		memcpy(cmd.args, "\xa0\x01", 2);
-		cmd.wlen = 2;
-		cmd.rlen = 13;
+		CMD_SETUP(cmd, "\xa0\x01", 13);
 		break;
 	case SYS_DVBC_ANNEX_A:
-		memcpy(cmd.args, "\x90\x01", 2);
-		cmd.wlen = 2;
-		cmd.rlen = 9;
+		CMD_SETUP(cmd, "\x90\x01", 9);
 		break;
 	case SYS_DVBT2:
-		memcpy(cmd.args, "\x50\x01", 2);
-		cmd.wlen = 2;
-		cmd.rlen = 14;
+		CMD_SETUP(cmd, "\x50\x01", 14);
 		break;
 	default:
 		ret = -EINVAL;
@@ -164,9 +162,7 @@ static int si2168_read_status(struct dvb_frontend *fe, enum fe_status *status)
 
 	/* BER */
 	if (*status & FE_HAS_VITERBI) {
-		memcpy(cmd.args, "\x82\x00", 2);
-		cmd.wlen = 2;
-		cmd.rlen = 3;
+		CMD_SETUP(cmd, "\x82\x00", 3);
 		ret = si2168_cmd_execute(client, &cmd);
 		if (ret)
 			goto err;
@@ -197,9 +193,7 @@ static int si2168_read_status(struct dvb_frontend *fe, enum fe_status *status)
 
 	/* UCB */
 	if (*status & FE_HAS_SYNC) {
-		memcpy(cmd.args, "\x84\x01", 2);
-		cmd.wlen = 2;
-		cmd.rlen = 3;
+		CMD_SETUP(cmd, "\x84\x01", 3);
 		ret = si2168_cmd_execute(client, &cmd);
 		if (ret)
 			goto err;
@@ -285,22 +279,18 @@ static int si2168_set_frontend(struct dvb_frontend *fe)
 			goto err;
 	}
 
-	memcpy(cmd.args, "\x88\x02\x02\x02\x02", 5);
-	cmd.wlen = 5;
-	cmd.rlen = 5;
+	CMD_SETUP(cmd, "\x88\x02\x02\x02\x02", 5);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
 	/* that has no big effect */
 	if (c->delivery_system == SYS_DVBT)
-		memcpy(cmd.args, "\x89\x21\x06\x11\xff\x98", 6);
+		CMD_SETUP(cmd, "\x89\x21\x06\x11\xff\x98", 3);
 	else if (c->delivery_system == SYS_DVBC_ANNEX_A)
-		memcpy(cmd.args, "\x89\x21\x06\x11\x89\xf0", 6);
+		CMD_SETUP(cmd, "\x89\x21\x06\x11\x89\xf0", 3);
 	else if (c->delivery_system == SYS_DVBT2)
-		memcpy(cmd.args, "\x89\x21\x06\x11\x89\x20", 6);
-	cmd.wlen = 6;
-	cmd.rlen = 3;
+		CMD_SETUP(cmd, "\x89\x21\x06\x11\x89\x20", 3);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
@@ -317,103 +307,77 @@ static int si2168_set_frontend(struct dvb_frontend *fe)
 			goto err;
 	}
 
-	memcpy(cmd.args, "\x51\x03", 2);
-	cmd.wlen = 2;
-	cmd.rlen = 12;
+	CMD_SETUP(cmd, "\x51\x03", 12);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
-	memcpy(cmd.args, "\x12\x08\x04", 3);
-	cmd.wlen = 3;
-	cmd.rlen = 3;
+	CMD_SETUP(cmd, "\x12\x08\x04", 3);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
-	memcpy(cmd.args, "\x14\x00\x0c\x10\x12\x00", 6);
-	cmd.wlen = 6;
-	cmd.rlen = 4;
+	CMD_SETUP(cmd, "\x14\x00\x0c\x10\x12\x00", 4);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
-	memcpy(cmd.args, "\x14\x00\x06\x10\x24\x00", 6);
-	cmd.wlen = 6;
-	cmd.rlen = 4;
+	CMD_SETUP(cmd, "\x14\x00\x06\x10\x24\x00", 4);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
-	memcpy(cmd.args, "\x14\x00\x07\x10\x00\x24", 6);
-	cmd.wlen = 6;
-	cmd.rlen = 4;
+	CMD_SETUP(cmd, "\x14\x00\x07\x10\x00\x24", 4);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
-	memcpy(cmd.args, "\x14\x00\x0a\x10\x00\x00", 6);
+	CMD_SETUP(cmd, "\x14\x00\x0a\x10\x00\x00", 4);
 	cmd.args[4] = delivery_system | bandwidth;
 	if (dev->spectral_inversion)
 		cmd.args[5] |= 1;
-	cmd.wlen = 6;
-	cmd.rlen = 4;
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
 	/* set DVB-C symbol rate */
 	if (c->delivery_system == SYS_DVBC_ANNEX_A) {
-		memcpy(cmd.args, "\x14\x00\x02\x11", 4);
+		CMD_SETUP(cmd, "\x14\x00\x02\x11\x00\x00", 4);
 		cmd.args[4] = ((c->symbol_rate / 1000) >> 0) & 0xff;
 		cmd.args[5] = ((c->symbol_rate / 1000) >> 8) & 0xff;
-		cmd.wlen = 6;
-		cmd.rlen = 4;
 		ret = si2168_cmd_execute(client, &cmd);
 		if (ret)
 			goto err;
 	}
 
-	memcpy(cmd.args, "\x14\x00\x0f\x10\x10\x00", 6);
-	cmd.wlen = 6;
-	cmd.rlen = 4;
+	CMD_SETUP(cmd, "\x14\x00\x0f\x10\x10\x00", 4);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
-	memcpy(cmd.args, "\x14\x00\x09\x10\xe3\x08", 6);
+	CMD_SETUP(cmd, "\x14\x00\x09\x10\xe3\x08", 4);
 	cmd.args[5] |= dev->ts_clock_inv ? 0x00 : 0x10;
-	cmd.wlen = 6;
-	cmd.rlen = 4;
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
-	memcpy(cmd.args, "\x14\x00\x08\x10\xd7\x05", 6);
+	CMD_SETUP(cmd, "\x14\x00\x08\x10\xd7\x05", 4);
 	cmd.args[5] |= dev->ts_clock_inv ? 0x00 : 0x10;
-	cmd.wlen = 6;
-	cmd.rlen = 4;
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
-	memcpy(cmd.args, "\x14\x00\x01\x12\x00\x00", 6);
-	cmd.wlen = 6;
-	cmd.rlen = 4;
+	CMD_SETUP(cmd, "\x14\x00\x01\x12\x00\x00", 4);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
-	memcpy(cmd.args, "\x14\x00\x01\x03\x0c\x00", 6);
-	cmd.wlen = 6;
-	cmd.rlen = 4;
+	CMD_SETUP(cmd, "\x14\x00\x01\x03\x0c\x00", 4);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
-	memcpy(cmd.args, "\x85", 1);
-	cmd.wlen = 1;
-	cmd.rlen = 1;
+	CMD_SETUP(cmd, "\x85", 1);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
@@ -443,26 +407,20 @@ static int si2168_init(struct dvb_frontend *fe)
 	dev_dbg(&client->dev, "\n");
 
 	/* initialize */
-	memcpy(cmd.args, "\xc0\x12\x00\x0c\x00\x0d\x16\x00\x00\x00\x00\x00\x00", 13);
-	cmd.wlen = 13;
-	cmd.rlen = 0;
+	CMD_SETUP(cmd, "\xc0\x12\x00\x0c\x00\x0d\x16\x00\x00\x00\x00\x00\x00", 0);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
 	if (dev->warm) {
 		/* resume */
-		memcpy(cmd.args, "\xc0\x06\x08\x0f\x00\x20\x21\x01", 8);
-		cmd.wlen = 8;
-		cmd.rlen = 1;
+		CMD_SETUP(cmd, "\xc0\x06\x08\x0f\x00\x20\x21\x01", 1);
 		ret = si2168_cmd_execute(client, &cmd);
 		if (ret)
 			goto err;
 
 		udelay(100);
-		memcpy(cmd.args, "\x85", 1);
-		cmd.wlen = 1;
-		cmd.rlen = 1;
+		CMD_SETUP(cmd, "\x85", 1);
 		ret = si2168_cmd_execute(client, &cmd);
 		if (ret)
 			goto err;
@@ -471,9 +429,7 @@ static int si2168_init(struct dvb_frontend *fe)
 	}
 
 	/* power up */
-	memcpy(cmd.args, "\xc0\x06\x01\x0f\x00\x20\x20\x01", 8);
-	cmd.wlen = 8;
-	cmd.rlen = 1;
+	CMD_SETUP(cmd, "\xc0\x06\x01\x0f\x00\x20\x20\x01", 1);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
@@ -541,17 +497,13 @@ static int si2168_init(struct dvb_frontend *fe)
 
 	release_firmware(fw);
 
-	memcpy(cmd.args, "\x01\x01", 2);
-	cmd.wlen = 2;
-	cmd.rlen = 1;
+	CMD_SETUP(cmd, "\x01\x01", 1);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
 
 	/* query firmware version */
-	memcpy(cmd.args, "\x11", 1);
-	cmd.wlen = 1;
-	cmd.rlen = 10;
+	CMD_SETUP(cmd, "\x11", 10);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
@@ -609,9 +561,7 @@ static int si2168_sleep(struct dvb_frontend *fe)
 	if (dev->version > ('B' << 24 | 4 << 16 | 0 << 8 | 11 << 0))
 		dev->warm = false;
 
-	memcpy(cmd.args, "\x13", 1);
-	cmd.wlen = 1;
-	cmd.rlen = 0;
+	CMD_SETUP(cmd, "\x13", 0);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
@@ -637,9 +587,7 @@ static int si2168_select(struct i2c_mux_core *muxc, u32 chan)
 	struct si2168_cmd cmd;
 
 	/* open I2C gate */
-	memcpy(cmd.args, "\xc0\x0d\x01", 3);
-	cmd.wlen = 3;
-	cmd.rlen = 0;
+	CMD_SETUP(cmd, "\xc0\x0d\x01", 0);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
@@ -657,9 +605,7 @@ static int si2168_deselect(struct i2c_mux_core *muxc, u32 chan)
 	struct si2168_cmd cmd;
 
 	/* close I2C gate */
-	memcpy(cmd.args, "\xc0\x0d\x00", 3);
-	cmd.wlen = 3;
-	cmd.rlen = 0;
+	CMD_SETUP(cmd, "\xc0\x0d\x00", 0);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err;
@@ -730,25 +676,19 @@ static int si2168_probe(struct i2c_client *client,
 	mutex_init(&dev->i2c_mutex);
 
 	/* Initialize */
-	memcpy(cmd.args, "\xc0\x12\x00\x0c\x00\x0d\x16\x00\x00\x00\x00\x00\x00", 13);
-	cmd.wlen = 13;
-	cmd.rlen = 0;
+	CMD_SETUP(cmd, "\xc0\x12\x00\x0c\x00\x0d\x16\x00\x00\x00\x00\x00\x00", 0);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err_kfree;
 
 	/* Power up */
-	memcpy(cmd.args, "\xc0\x06\x01\x0f\x00\x20\x20\x01", 8);
-	cmd.wlen = 8;
-	cmd.rlen = 1;
+	CMD_SETUP(cmd, "\xc0\x06\x01\x0f\x00\x20\x20\x01", 1);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err_kfree;
 
 	/* Query chip revision */
-	memcpy(cmd.args, "\x02", 1);
-	cmd.wlen = 1;
-	cmd.rlen = 13;
+	CMD_SETUP(cmd, "\x02", 13);
 	ret = si2168_cmd_execute(client, &cmd);
 	if (ret)
 		goto err_kfree;
-- 
2.17.1