[media] rtl2832: change the i2c gate to be mux-locked

The root i2c adapter lock is then no longer held by the i2c mux during
accesses behind the i2c gate, and such accesses need to take that lock
just like any other ordinary i2c accesses do.

So, declare the i2c gate mux-locked, and zap the regmap overrides
that makes the i2c accesses unlocked and use plain old regmap
accesses. This also removes the need for the regmap wrappers used by
rtl2832_sdr, so deconvolute the code further and provide the regmap
handle directly instead of the wrapper functions.

Tested-by: Antti Palosaari <[e-mail]>
Signed-off-by: Peter Rosin <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>

Documentation/i2c/i2c-topology

···
 In drivers/media/
 dvb-frontends/m88ds3103   Parent-locked
 dvb-frontends/rtl2830     Parent-locked
-dvb-frontends/rtl2832     Parent-locked
+dvb-frontends/rtl2832     Mux-locked
 dvb-frontends/si2168      Mux-locked
 usb/cx231xx/              Parent-locked
 

drivers/media/dvb-frontends/rtl2832.c

···
 	[DVBT_REG_4MSEL]	= {0x013,  0, 0},
 };
 
-/* Our regmap is bypassing I2C adapter lock, thus we do it! */
-static int rtl2832_bulk_write(struct i2c_client *client, unsigned int reg,
-			      const void *val, size_t val_count)
-{
-	struct rtl2832_dev *dev = i2c_get_clientdata(client);
-	int ret;
-
-	i2c_lock_adapter(client->adapter);
-	ret = regmap_bulk_write(dev->regmap, reg, val, val_count);
-	i2c_unlock_adapter(client->adapter);
-	return ret;
-}
-
-static int rtl2832_update_bits(struct i2c_client *client, unsigned int reg,
-			       unsigned int mask, unsigned int val)
-{
-	struct rtl2832_dev *dev = i2c_get_clientdata(client);
-	int ret;
-
-	i2c_lock_adapter(client->adapter);
-	ret = regmap_update_bits(dev->regmap, reg, mask, val);
-	i2c_unlock_adapter(client->adapter);
-	return ret;
-}
-
-static int rtl2832_bulk_read(struct i2c_client *client, unsigned int reg,
-			     void *val, size_t val_count)
-{
-	struct rtl2832_dev *dev = i2c_get_clientdata(client);
-	int ret;
-
-	i2c_lock_adapter(client->adapter);
-	ret = regmap_bulk_read(dev->regmap, reg, val, val_count);
-	i2c_unlock_adapter(client->adapter);
-	return ret;
-}
-
 static int rtl2832_rd_demod_reg(struct rtl2832_dev *dev, int reg, u32 *val)
 {
 	struct i2c_client *client = dev->client;
···
 	len = (msb >> 3) + 1;
 	mask = REG_MASK(msb - lsb);
 
-	ret = rtl2832_bulk_read(client, reg_start_addr, reading, len);
+	ret = regmap_bulk_read(dev->regmap, reg_start_addr, reading, len);
 	if (ret)
 		goto err;
 
···
 	len = (msb >> 3) + 1;
 	mask = REG_MASK(msb - lsb);
 
-	ret = rtl2832_bulk_read(client, reg_start_addr, reading, len);
+	ret = regmap_bulk_read(dev->regmap, reg_start_addr, reading, len);
 	if (ret)
 		goto err;
 
···
 	for (i = 0; i < len; i++)
 		writing[i] = (writing_tmp >> ((len - 1 - i) * 8)) & 0xff;
 
-	ret = rtl2832_bulk_write(client, reg_start_addr, writing, len);
+	ret = regmap_bulk_write(dev->regmap, reg_start_addr, writing, len);
 	if (ret)
 		goto err;
 
···
 	}
 
 	for (j = 0; j < sizeof(bw_params[0]); j++) {
-		ret = rtl2832_bulk_write(client, 0x11c + j, &bw_params[i][j], 1);
+		ret = regmap_bulk_write(dev->regmap,
+					0x11c + j, &bw_params[i][j], 1);
 		if (ret)
 			goto err;
 	}
···
 	if (dev->sleeping)
 		return 0;
 
-	ret = rtl2832_bulk_read(client, 0x33c, buf, 2);
+	ret = regmap_bulk_read(dev->regmap, 0x33c, buf, 2);
 	if (ret)
 		goto err;
 
-	ret = rtl2832_bulk_read(client, 0x351, &buf[2], 1);
+	ret = regmap_bulk_read(dev->regmap, 0x351, &buf[2], 1);
 	if (ret)
 		goto err;
 
···
 	/* signal strength */
 	if (dev->fe_status & FE_HAS_SIGNAL) {
 		/* read digital AGC */
-		ret = rtl2832_bulk_read(client, 0x305, &u8tmp, 1);
+		ret = regmap_bulk_read(dev->regmap, 0x305, &u8tmp, 1);
 		if (ret)
 			goto err;
 
···
 			{87659938, 87659938, 87885178, 88241743},
 		};
 
-		ret = rtl2832_bulk_read(client, 0x33c, &u8tmp, 1);
+		ret = regmap_bulk_read(dev->regmap, 0x33c, &u8tmp, 1);
 		if (ret)
 			goto err;
 
···
 		if (hierarchy > HIERARCHY_NUM - 1)
 			goto err;
 
-		ret = rtl2832_bulk_read(client, 0x40c, buf, 2);
+		ret = regmap_bulk_read(dev->regmap, 0x40c, buf, 2);
 		if (ret)
 			goto err;
 
···
 
 	/* BER */
 	if (dev->fe_status & FE_HAS_LOCK) {
-		ret = rtl2832_bulk_read(client, 0x34e, buf, 2);
+		ret = regmap_bulk_read(dev->regmap, 0x34e, buf, 2);
 		if (ret)
 			goto err;
 
···
 
 /*
  * I2C gate/mux/repeater logic
- * We must use unlocked __i2c_transfer() here (through regmap) because of I2C
- * adapter lock is already taken by tuner driver.
  * There is delay mechanism to avoid unneeded I2C gate open / close. Gate close
  * is delayed here a little bit in order to see if there is sequence of I2C
  * messages sent to same I2C bus.
···
 	int ret;
 
 	/* close gate */
-	ret = rtl2832_update_bits(dev->client, 0x101, 0x08, 0x00);
+	ret = regmap_update_bits(dev->regmap, 0x101, 0x08, 0x00);
 	if (ret)
 		goto err;
 
···
 	/* terminate possible gate closing */
 	cancel_delayed_work(&dev->i2c_gate_work);
 
-	/*
-	 * I2C adapter lock is already taken and due to that we will use
-	 * regmap_update_bits() which does not lock again I2C adapter.
-	 */
+	/* open gate */
 	ret = regmap_update_bits(dev->regmap, 0x101, 0x08, 0x08);
 	if (ret)
 		goto err;
···
 }
 
 /*
- * We implement own I2C access routines for regmap in order to get manual access
- * to I2C adapter lock, which is needed for I2C mux adapter.
- */
-static int rtl2832_regmap_read(void *context, const void *reg_buf,
-			       size_t reg_size, void *val_buf, size_t val_size)
-{
-	struct i2c_client *client = context;
-	int ret;
-	struct i2c_msg msg[2] = {
-		{
-			.addr = client->addr,
-			.flags = 0,
-			.len = reg_size,
-			.buf = (u8 *)reg_buf,
-		}, {
-			.addr = client->addr,
-			.flags = I2C_M_RD,
-			.len = val_size,
-			.buf = val_buf,
-		}
-	};
-
-	ret = __i2c_transfer(client->adapter, msg, 2);
-	if (ret != 2) {
-		dev_warn(&client->dev, "i2c reg read failed %d reg %02x\n",
-			 ret, *(u8 *)reg_buf);
-		if (ret >= 0)
-			ret = -EREMOTEIO;
-		return ret;
-	}
-	return 0;
-}
-
-static int rtl2832_regmap_write(void *context, const void *data, size_t count)
-{
-	struct i2c_client *client = context;
-	int ret;
-	struct i2c_msg msg[1] = {
-		{
-			.addr = client->addr,
-			.flags = 0,
-			.len = count,
-			.buf = (u8 *)data,
-		}
-	};
-
-	ret = __i2c_transfer(client->adapter, msg, 1);
-	if (ret != 1) {
-		dev_warn(&client->dev, "i2c reg write failed %d reg %02x\n",
-			 ret, *(u8 *)data);
-		if (ret >= 0)
-			ret = -EREMOTEIO;
-		return ret;
-	}
-	return 0;
-}
-
-static int rtl2832_regmap_gather_write(void *context, const void *reg,
-				       size_t reg_len, const void *val,
-				       size_t val_len)
-{
-	struct i2c_client *client = context;
-	int ret;
-	u8 buf[256];
-	struct i2c_msg msg[1] = {
-		{
-			.addr = client->addr,
-			.flags = 0,
-			.len = 1 + val_len,
-			.buf = buf,
-		}
-	};
-
-	buf[0] = *(u8 const *)reg;
-	memcpy(&buf[1], val, val_len);
-
-	ret = __i2c_transfer(client->adapter, msg, 1);
-	if (ret != 1) {
-		dev_warn(&client->dev, "i2c reg write failed %d reg %02x\n",
-			 ret, *(u8 const *)reg);
-		if (ret >= 0)
-			ret = -EREMOTEIO;
-		return ret;
-	}
-	return 0;
-}
-
-/*
  * FIXME: Hack. Implement own regmap locking in order to silence lockdep
  * recursive lock warning. That happens when regmap I2C client calls I2C mux
  * adapter, which leads demod I2C repeater enable via demod regmap. Operation
···
 		ret = rtl2832_wr_demod_reg(dev, DVBT_SOFT_RST, 0x0);
 		if (ret)
 			goto err;
-		ret = rtl2832_bulk_write(client, 0x10c, "\x5f\xff", 2);
+		ret = regmap_bulk_write(dev->regmap, 0x10c, "\x5f\xff", 2);
 		if (ret)
 			goto err;
 		ret = rtl2832_wr_demod_reg(dev, DVBT_PIP_ON, 0x1);
 		if (ret)
 			goto err;
-		ret = rtl2832_bulk_write(client, 0x0bc, "\x18", 1);
+		ret = regmap_bulk_write(dev->regmap, 0x0bc, "\x18", 1);
 		if (ret)
 			goto err;
-		ret = rtl2832_bulk_write(client, 0x192, "\x7f\xf7\xff", 3);
+		ret = regmap_bulk_write(dev->regmap, 0x192, "\x7f\xf7\xff", 3);
 		if (ret)
 			goto err;
 	} else {
-		ret = rtl2832_bulk_write(client, 0x192, "\x00\x0f\xff", 3);
+		ret = regmap_bulk_write(dev->regmap, 0x192, "\x00\x0f\xff", 3);
 		if (ret)
 			goto err;
-		ret = rtl2832_bulk_write(client, 0x0bc, "\x08", 1);
+		ret = regmap_bulk_write(dev->regmap, 0x0bc, "\x08", 1);
 		if (ret)
 			goto err;
 		ret = rtl2832_wr_demod_reg(dev, DVBT_PIP_ON, 0x0);
 		if (ret)
 			goto err;
-		ret = rtl2832_bulk_write(client, 0x10c, "\x00\x00", 2);
+		ret = regmap_bulk_write(dev->regmap, 0x10c, "\x00\x00", 2);
 		if (ret)
 			goto err;
 		ret = rtl2832_wr_demod_reg(dev, DVBT_SOFT_RST, 0x1);
···
 	else
 		u8tmp = 0x00;
 
-	ret = rtl2832_update_bits(client, 0x061, 0xc0, u8tmp);
+	ret = regmap_update_bits(dev->regmap, 0x061, 0xc0, u8tmp);
 	if (ret)
 		goto err;
 
···
 	buf[1] = (dev->filters >>  8) & 0xff;
 	buf[2] = (dev->filters >> 16) & 0xff;
 	buf[3] = (dev->filters >> 24) & 0xff;
-	ret = rtl2832_bulk_write(client, 0x062, buf, 4);
+	ret = regmap_bulk_write(dev->regmap, 0x062, buf, 4);
 	if (ret)
 		goto err;
 
 	/* add PID */
 	buf[0] = (pid >> 8) & 0xff;
 	buf[1] = (pid >> 0) & 0xff;
-	ret = rtl2832_bulk_write(client, 0x066 + 2 * index, buf, 2);
+	ret = regmap_bulk_write(dev->regmap, 0x066 + 2 * index, buf, 2);
 	if (ret)
 		goto err;
 
···
 	struct rtl2832_dev *dev;
 	int ret;
 	u8 tmp;
-	static const struct regmap_bus regmap_bus = {
-		.read = rtl2832_regmap_read,
-		.write = rtl2832_regmap_write,
-		.gather_write = rtl2832_regmap_gather_write,
-		.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
-	};
 	static const struct regmap_range_cfg regmap_range_cfg[] = {
 		{
 			.selector_reg     = 0x00,
···
 	dev->regmap_config.ranges = regmap_range_cfg,
 	dev->regmap_config.num_ranges = ARRAY_SIZE(regmap_range_cfg),
 	dev->regmap_config.cache_type = REGCACHE_NONE,
-	dev->regmap = regmap_init(&client->dev, &regmap_bus, client,
-				  &dev->regmap_config);
+	dev->regmap = regmap_init_i2c(client, &dev->regmap_config);
 	if (IS_ERR(dev->regmap)) {
 		ret = PTR_ERR(dev->regmap);
 		goto err_kfree;
 	}
 
 	/* check if the demod is there */
-	ret = rtl2832_bulk_read(client, 0x000, &tmp, 1);
+	ret = regmap_bulk_read(dev->regmap, 0x000, &tmp, 1);
 	if (ret)
 		goto err_regmap_exit;
 
 	/* create muxed i2c adapter for demod tuner bus */
-	dev->muxc = i2c_mux_alloc(i2c, &i2c->dev, 1, 0, 0,
+	dev->muxc = i2c_mux_alloc(i2c, &i2c->dev, 1, 0, I2C_MUX_LOCKED,
 				  rtl2832_select, rtl2832_deselect);
 	if (!dev->muxc) {
 		ret = -ENOMEM;
···
 	pdata->slave_ts_ctrl = rtl2832_slave_ts_ctrl;
 	pdata->pid_filter = rtl2832_pid_filter;
 	pdata->pid_filter_ctrl = rtl2832_pid_filter_ctrl;
-	pdata->bulk_read = rtl2832_bulk_read;
-	pdata->bulk_write = rtl2832_bulk_write;
-	pdata->update_bits = rtl2832_update_bits;
+	pdata->regmap = dev->regmap;
 
 	dev_info(&client->dev, "Realtek RTL2832 successfully attached\n");
 	return 0;

drivers/media/dvb-frontends/rtl2832.h

···
 	int (*pid_filter)(struct dvb_frontend *, u8, u16, int);
 	int (*pid_filter_ctrl)(struct dvb_frontend *, int);
 /* private: Register access for SDR module use only */
-	int (*bulk_read)(struct i2c_client *, unsigned int, void *, size_t);
-	int (*bulk_write)(struct i2c_client *, unsigned int, const void *, size_t);
-	int (*update_bits)(struct i2c_client *, unsigned int, unsigned int, unsigned int);
+	struct regmap *regmap;
 };
 
 #endif /* RTL2832_H */

drivers/media/dvb-frontends/rtl2832_sdr.c

···
 #include <linux/platform_device.h>
 #include <linux/jiffies.h>
 #include <linux/math64.h>
+#include <linux/regmap.h>
 
 static bool rtl2832_sdr_emulated_fmt;
 module_param_named(emulated_formats, rtl2832_sdr_emulated_fmt, bool, 0644);
···
 {
 	struct platform_device *pdev = dev->pdev;
 	struct rtl2832_sdr_platform_data *pdata = pdev->dev.platform_data;
-	struct i2c_client *client = pdata->i2c_client;
+	struct regmap *regmap = pdata->regmap;
 
-	return pdata->bulk_write(client, reg, val, len);
+	return regmap_bulk_write(regmap, reg, val, len);
 }
 
 #if 0
···
 {
 	struct platform_device *pdev = dev->pdev;
 	struct rtl2832_sdr_platform_data *pdata = pdev->dev.platform_data;
-	struct i2c_client *client = pdata->i2c_client;
+	struct regmap *regmap = pdata->regmap;
 
-	return pdata->bulk_read(client, reg, val, len);
+	return regmap_bulk_read(regmap, reg, val, len);
 }
 #endif
 
···
 {
 	struct platform_device *pdev = dev->pdev;
 	struct rtl2832_sdr_platform_data *pdata = pdev->dev.platform_data;
-	struct i2c_client *client = pdata->i2c_client;
+	struct regmap *regmap = pdata->regmap;
 
-	return pdata->update_bits(client, reg, mask, val);
+	return regmap_update_bits(regmap, reg, mask, val);
 }
 
 /* Private functions */

drivers/media/dvb-frontends/rtl2832_sdr.h

···
 #define RTL2832_SDR_TUNER_R828D     0x2b
 	u8 tuner;
 
-	struct i2c_client *i2c_client;
-	int (*bulk_read)(struct i2c_client *, unsigned int, void *, size_t);
-	int (*bulk_write)(struct i2c_client *, unsigned int, const void *, size_t);
-	int (*update_bits)(struct i2c_client *, unsigned int, unsigned int, unsigned int);
+	struct regmap *regmap;
 	struct dvb_frontend *dvb_frontend;
 	struct v4l2_subdev *v4l2_subdev;
 	struct dvb_usb_device *dvb_usb_device;

drivers/media/usb/dvb-usb-v2/rtl28xxu.c

···
 	case TUNER_RTL2832_R828D:
 		pdata.clk = dev->rtl2832_platform_data.clk;
 		pdata.tuner = dev->tuner;
-		pdata.i2c_client = dev->i2c_client_demod;
-		pdata.bulk_read = dev->rtl2832_platform_data.bulk_read;
-		pdata.bulk_write = dev->rtl2832_platform_data.bulk_write;
-		pdata.update_bits = dev->rtl2832_platform_data.update_bits;
+		pdata.regmap = dev->rtl2832_platform_data.regmap;
 		pdata.dvb_frontend = adap->fe[0];
 		pdata.dvb_usb_device = d;
 		pdata.v4l2_subdev = subdev;