From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-ww0-f42.google.com ([74.125.82.42]:63251 "EHLO mail-ww0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752621Ab1KFPTW (ORCPT ); Sun, 6 Nov 2011 10:19:22 -0500 Received: by wwf22 with SMTP id 22so3938879wwf.1 for ; Sun, 06 Nov 2011 07:19:20 -0800 (PST) Message-ID: <4eb6a578.8bcbe30a.30d9.fffff86a@mx.google.com> Subject: [PATCH] it913x-fe ver 1.10 correct SNR reading from frontend. From: Malcolm Priestley To: linux-media@vger.kernel.org Date: Sun, 06 Nov 2011 15:19:14 +0000 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-media-owner@vger.kernel.org List-ID: Correction of reading from frontend and represents a SNR nonlinear scale of minimum signal to full signal. Signed-off-by: Malcolm Priestley --- drivers/media/dvb/frontends/it913x-fe.c | 56 +++++++++++++++++++++++++++---- 1 files changed, 49 insertions(+), 7 deletions(-) diff --git a/drivers/media/dvb/frontends/it913x-fe.c b/drivers/media/dvb/frontends/it913x-fe.c index 6d12dcc..07c1b46 100644 --- a/drivers/media/dvb/frontends/it913x-fe.c +++ b/drivers/media/dvb/frontends/it913x-fe.c @@ -53,6 +53,8 @@ struct it913x_fe_state { struct ite_config *config; u8 i2c_addr; u32 frequency; + fe_modulation_t constellation; + fe_transmit_mode_t transmission_mode; u32 crystalFrequency; u32 adcFrequency; u8 tuner_type; @@ -496,14 +498,50 @@ static int it913x_fe_read_signal_strength(struct dvb_frontend *fe, return 0; } -static int it913x_fe_read_snr(struct dvb_frontend *fe, u16* snr) +static int it913x_fe_read_snr(struct dvb_frontend *fe, u16 *snr) { struct it913x_fe_state *state = fe->demodulator_priv; - int ret = it913x_read_reg_u8(state, SIGNAL_QUALITY); - ret = (ret * 0xff) / 0x64; - ret |= (ret << 0x8); - *snr = ~ret; - return 0; + int ret; + u8 reg[3]; + u32 snr_val, snr_min, snr_max; + u32 temp; + + ret = it913x_read_reg(state, 0x2c, reg, sizeof(reg)); + + snr_val = (u32)(reg[2] << 16) | (reg[1] < 8) | reg[0]; + + ret |= it913x_read_reg(state, 0xf78b, reg, 1); + if (reg[0]) + snr_val /= reg[0]; + + if (state->transmission_mode == TRANSMISSION_MODE_2K) + snr_val *= 4; + else if (state->transmission_mode == TRANSMISSION_MODE_4K) + snr_val *= 2; + + if (state->constellation == QPSK) { + snr_min = 0xb4711; + snr_max = 0x191451; + } else if (state->constellation == QAM_16) { + snr_min = 0x4f0d5; + snr_max = 0xc7925; + } else if (state->constellation == QAM_64) { + snr_min = 0x256d0; + snr_max = 0x626be; + } else + return -EINVAL; + + if (snr_val < snr_min) + *snr = 0; + else if (snr_val < snr_max) { + temp = (snr_val - snr_min) >> 5; + temp *= 0xffff; + temp /= (snr_max - snr_min) >> 5; + *snr = (u16)temp; + } else + *snr = 0xffff; + + return (ret < 0) ? -ENODEV : 0; } static int it913x_fe_read_ber(struct dvb_frontend *fe, u32 *ber) @@ -530,9 +568,13 @@ static int it913x_fe_get_frontend(struct dvb_frontend *fe, if (reg[3] < 3) p->u.ofdm.constellation = fe_con[reg[3]]; + state->constellation = p->u.ofdm.constellation; + if (reg[0] < 3) p->u.ofdm.transmission_mode = fe_mode[reg[0]]; + state->transmission_mode = p->u.ofdm.transmission_mode; + if (reg[1] < 4) p->u.ofdm.guard_interval = fe_gi[reg[1]]; @@ -888,5 +930,5 @@ static struct dvb_frontend_ops it913x_fe_ofdm_ops = { MODULE_DESCRIPTION("it913x Frontend and it9137 tuner"); MODULE_AUTHOR("Malcolm Priestley tvboxspy@gmail.com"); -MODULE_VERSION("1.09"); +MODULE_VERSION("1.10"); MODULE_LICENSE("GPL"); -- 1.7.5.4