Commit 4594cb4b authored by Krzysztof Kozlowski's avatar Krzysztof Kozlowski Committed by Greg Kroah-Hartman
Browse files

slimbus: qcom-ngd-ctrl: add support for 44.1 Khz frequency 



Add support for 44.1Khz frequency by dynamically calculating the slimbus
parameters instead of statically defining them.

Co-developed-by: default avatarPrudhvi Yarlagadda <pyarlaga@codeaurora.org>
Signed-off-by: default avatarPrudhvi Yarlagadda <pyarlaga@codeaurora.org>
Signed-off-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: default avatarSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221118065246.6835-5-srinivas.kandagatla@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 434d2572

drivers/slimbus/qcom-ngd-ctrl.c

+59 −5
Original line number Diff line number Diff line
@@ -944,6 +944,54 @@ static int qcom_slim_ngd_xfer_msg_sync(struct slim_controller *ctrl, 
	return ret;

}



static int qcom_slim_calc_coef(struct slim_stream_runtime *rt, int *exp)

{

	struct slim_controller *ctrl = rt->dev->ctrl;

	int coef;



	if (rt->ratem * ctrl->a_framer->superfreq < rt->rate)

		rt->ratem++;



	coef = rt->ratem;

	*exp = 0;



	/*

	 * CRM = Cx(2^E) is the formula we are using.

	 * Here C is the coffecient and E is the exponent.

	 * CRM is the Channel Rate Multiplier.

	 * Coefficeint should be either 1 or 3 and exponenet

	 * should be an integer between 0 to 9, inclusive.

	 */

	while (1) {

		while ((coef & 0x1) != 0x1) {

			coef >>= 1;

			*exp = *exp + 1;

		}



		if (coef <= 3)

			break;



		coef++;

	}



	/*

	 * we rely on the coef value (1 or 3) to set a bit

	 * in the slimbus message packet. This bit is

	 * BIT(5) which is the segment rate coefficient.

	 */

	if (coef == 1) {

		if (*exp > 9)

			return -EIO;

		coef = 0;

	} else {

		if (*exp > 8)

			return -EIO;

		coef = 1;

	}



	return coef;

}



static int qcom_slim_ngd_enable_stream(struct slim_stream_runtime *rt)

{

	struct slim_device *sdev = rt->dev;
@@ -967,16 +1015,22 @@ static int qcom_slim_ngd_enable_stream(struct slim_stream_runtime *rt) 
		struct slim_port *port = &rt->ports[i];



		if (txn.msg->num_bytes == 0) {

			int seg_interval = SLIM_SLOTS_PER_SUPERFRAME/rt->ratem;

			int exp;

			int exp = 0, coef = 0;



			wbuf[txn.msg->num_bytes++] = sdev->laddr;

			wbuf[txn.msg->num_bytes] = rt->bps >> 2 |

						   (port->ch.aux_fmt << 6);



			/* Data channel segment interval not multiple of 3 */

			exp = seg_interval % 3;

			if (exp)

			/* calculate coef dynamically */

			coef = qcom_slim_calc_coef(rt, &exp);

			if (coef < 0) {

				dev_err(&sdev->dev,

				"%s: error calculating coef %d\n", __func__,

									coef);

				return -EIO;

			}



			if (coef)

				wbuf[txn.msg->num_bytes] |= BIT(5);



			txn.msg->num_bytes++;