gp8psk: Fix DVB frontend attach

The DVB binding schema at the DVB core assumes that the frontend is a
separate driver.  Faling to do that causes OOPS when the module is
removed, as it tries to do a symbol_put_addr on an internal symbol,
causing craches like:

    WARNING: CPU: 1 PID: 28102 at kernel/module.c:1108 module_put+0x57/0x70
    Modules linked in: dvb_usb_gp8psk(-) dvb_usb dvb_core nvidia_drm(PO) nvidia_modeset(PO) snd_hda_codec_hdmi snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd soundcore nvidia(PO) [last unloaded: rc_core]
    CPU: 1 PID: 28102 Comm: rmmod Tainted: P        WC O 4.8.4-build.1 #1
    Hardware name: MSI MS-7309/MS-7309, BIOS V1.12 02/23/2009
    Call Trace:
       dump_stack+0x44/0x64
       __warn+0xfa/0x120
       module_put+0x57/0x70
       module_put+0x57/0x70
       warn_slowpath_null+0x23/0x30
       module_put+0x57/0x70
       gp8psk_fe_set_frontend+0x460/0x460 [dvb_usb_gp8psk]
       symbol_put_addr+0x27/0x50
       dvb_usb_adapter_frontend_exit+0x3a/0x70 [dvb_usb]

From Derek's tests:
    "Attach bug is fixed, tuning works, module unloads without
     crashing. Everything seems ok!"

Reported-by: Derek <user.vdr@gmail.com>
Tested-by: Derek <user.vdr@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 485 insertions, 0 deletions

diff --git a/drivers/media/dvb-frontends/Kconfig b/drivers/media/dvb-frontends/Kconfig
index 012225587c25..b71b747ee0ba 100644
--- a/drivers/media/dvb-frontends/Kconfig
+++ b/drivers/media/dvb-frontends/Kconfig
@@ -513,6 +513,11 @@ config DVB_AS102_FE
 	depends on DVB_CORE
 	default DVB_AS102
 
+config DVB_GP8PSK_FE
+	tristate
+	depends on DVB_CORE
+	default DVB_USB_GP8PSK
+
 comment "DVB-C (cable) frontends"
 	depends on DVB_CORE
 
diff --git a/drivers/media/dvb-frontends/Makefile b/drivers/media/dvb-frontends/Makefile
index e90165ad361b..93921a4eaa27 100644
--- a/drivers/media/dvb-frontends/Makefile
+++ b/drivers/media/dvb-frontends/Makefile
@@ -121,6 +121,7 @@ obj-$(CONFIG_DVB_RTL2832_SDR) += rtl2832_sdr.o
 obj-$(CONFIG_DVB_M88RS2000) += m88rs2000.o
 obj-$(CONFIG_DVB_AF9033) += af9033.o
 obj-$(CONFIG_DVB_AS102_FE) += as102_fe.o
+obj-$(CONFIG_DVB_GP8PSK_FE) += gp8psk-fe.o
 obj-$(CONFIG_DVB_TC90522) += tc90522.o
 obj-$(CONFIG_DVB_HORUS3A) += horus3a.o
 obj-$(CONFIG_DVB_ASCOT2E) += ascot2e.o
diff --git a/drivers/media/dvb-frontends/gp8psk-fe.c b/drivers/media/dvb-frontends/gp8psk-fe.c
new file mode 100644
index 000000000000..be19afeed7a9
--- /dev/null
+++ b/drivers/media/dvb-frontends/gp8psk-fe.c
@@ -0,0 +1,397 @@
+/* DVB USB compliant Linux driver for the
+ *  - GENPIX 8pks/qpsk/DCII USB2.0 DVB-S module
+ *
+ * Copyright (C) 2006,2007 Alan Nisota (alannisota@gmail.com)
+ * Copyright (C) 2006,2007 Genpix Electronics (genpix@genpix-electronics.com)
+ *
+ * Thanks to GENPIX for the sample code used to implement this module.
+ *
+ * This module is based off the vp7045 and vp702x modules
+ *
+ *	This program is free software; you can redistribute it and/or modify it
+ *	under the terms of the GNU General Public License as published by the Free
+ *	Software Foundation, version 2.
+ *
+ * see Documentation/dvb/README.dvb-usb for more information
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "gp8psk-fe.h"
+#include "dvb_frontend.h"
+
+static int debug;
+module_param(debug, int, 0644);
+MODULE_PARM_DESC(debug, "Turn on/off debugging (default:off).");
+
+#define dprintk(fmt, arg...) do {					\
+	if (debug)							\
+		printk(KERN_DEBUG pr_fmt("%s: " fmt),			\
+		       __func__, ##arg);				\
+} while (0)
+
+struct gp8psk_fe_state {
+	struct dvb_frontend fe;
+	void *priv;
+	const struct gp8psk_fe_ops *ops;
+	bool is_rev1;
+	u8 lock;
+	u16 snr;
+	unsigned long next_status_check;
+	unsigned long status_check_interval;
+};
+
+static int gp8psk_tuned_to_DCII(struct dvb_frontend *fe)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+	u8 status;
+
+	st->ops->in(st->priv, GET_8PSK_CONFIG, 0, 0, &status, 1);
+	return status & bmDCtuned;
+}
+
+static int gp8psk_set_tuner_mode(struct dvb_frontend *fe, int mode)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+
+	return st->ops->out(st->priv, SET_8PSK_CONFIG, mode, 0, NULL, 0);
+}
+
+static int gp8psk_fe_update_status(struct gp8psk_fe_state *st)
+{
+	u8 buf[6];
+	if (time_after(jiffies,st->next_status_check)) {
+		st->ops->in(st->priv, GET_SIGNAL_LOCK, 0, 0, &st->lock, 1);
+		st->ops->in(st->priv, GET_SIGNAL_STRENGTH, 0, 0, buf, 6);
+		st->snr = (buf[1]) << 8 | buf[0];
+		st->next_status_check = jiffies + (st->status_check_interval*HZ)/1000;
+	}
+	return 0;
+}
+
+static int gp8psk_fe_read_status(struct dvb_frontend *fe,
+				 enum fe_status *status)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+	gp8psk_fe_update_status(st);
+
+	if (st->lock)
+		*status = FE_HAS_LOCK | FE_HAS_SYNC | FE_HAS_VITERBI | FE_HAS_SIGNAL | FE_HAS_CARRIER;
+	else
+		*status = 0;
+
+	if (*status & FE_HAS_LOCK)
+		st->status_check_interval = 1000;
+	else
+		st->status_check_interval = 100;
+	return 0;
+}
+
+/* not supported by this Frontend */
+static int gp8psk_fe_read_ber(struct dvb_frontend* fe, u32 *ber)
+{
+	(void) fe;
+	*ber = 0;
+	return 0;
+}
+
+/* not supported by this Frontend */
+static int gp8psk_fe_read_unc_blocks(struct dvb_frontend* fe, u32 *unc)
+{
+	(void) fe;
+	*unc = 0;
+	return 0;
+}
+
+static int gp8psk_fe_read_snr(struct dvb_frontend* fe, u16 *snr)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+	gp8psk_fe_update_status(st);
+	/* snr is reported in dBu*256 */
+	*snr = st->snr;
+	return 0;
+}
+
+static int gp8psk_fe_read_signal_strength(struct dvb_frontend* fe, u16 *strength)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+	gp8psk_fe_update_status(st);
+	/* snr is reported in dBu*256 */
+	/* snr / 38.4 ~= 100% strength */
+	/* snr * 17 returns 100% strength as 65535 */
+	if (st->snr > 0xf00)
+		*strength = 0xffff;
+	else
+		*strength = (st->snr << 4) + st->snr; /* snr*17 */
+	return 0;
+}
+
+static int gp8psk_fe_get_tune_settings(struct dvb_frontend* fe, struct dvb_frontend_tune_settings *tune)
+{
+	tune->min_delay_ms = 800;
+	return 0;
+}
+
+static int gp8psk_fe_set_frontend(struct dvb_frontend *fe)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+	u8 cmd[10];
+	u32 freq = c->frequency * 1000;
+
+	dprintk("%s()\n", __func__);
+
+	cmd[4] = freq         & 0xff;
+	cmd[5] = (freq >> 8)  & 0xff;
+	cmd[6] = (freq >> 16) & 0xff;
+	cmd[7] = (freq >> 24) & 0xff;
+
+	/* backwards compatibility: DVB-S + 8-PSK were used for Turbo-FEC */
+	if (c->delivery_system == SYS_DVBS && c->modulation == PSK_8)
+		c->delivery_system = SYS_TURBO;
+
+	switch (c->delivery_system) {
+	case SYS_DVBS:
+		if (c->modulation != QPSK) {
+			dprintk("%s: unsupported modulation selected (%d)\n",
+				__func__, c->modulation);
+			return -EOPNOTSUPP;
+		}
+		c->fec_inner = FEC_AUTO;
+		break;
+	case SYS_DVBS2: /* kept for backwards compatibility */
+		dprintk("%s: DVB-S2 delivery system selected\n", __func__);
+		break;
+	case SYS_TURBO:
+		dprintk("%s: Turbo-FEC delivery system selected\n", __func__);
+		break;
+
+	default:
+		dprintk("%s: unsupported delivery system selected (%d)\n",
+			__func__, c->delivery_system);
+		return -EOPNOTSUPP;
+	}
+
+	cmd[0] =  c->symbol_rate        & 0xff;
+	cmd[1] = (c->symbol_rate >>  8) & 0xff;
+	cmd[2] = (c->symbol_rate >> 16) & 0xff;
+	cmd[3] = (c->symbol_rate >> 24) & 0xff;
+	switch (c->modulation) {
+	case QPSK:
+		if (st->is_rev1)
+			if (gp8psk_tuned_to_DCII(fe))
+				st->ops->reload(st->priv);
+		switch (c->fec_inner) {
+		case FEC_1_2:
+			cmd[9] = 0; break;
+		case FEC_2_3:
+			cmd[9] = 1; break;
+		case FEC_3_4:
+			cmd[9] = 2; break;
+		case FEC_5_6:
+			cmd[9] = 3; break;
+		case FEC_7_8:
+			cmd[9] = 4; break;
+		case FEC_AUTO:
+			cmd[9] = 5; break;
+		default:
+			cmd[9] = 5; break;
+		}
+		if (c->delivery_system == SYS_TURBO)
+			cmd[8] = ADV_MOD_TURBO_QPSK;
+		else
+			cmd[8] = ADV_MOD_DVB_QPSK;
+		break;
+	case PSK_8: /* PSK_8 is for compatibility with DN */
+		cmd[8] = ADV_MOD_TURBO_8PSK;
+		switch (c->fec_inner) {
+		case FEC_2_3:
+			cmd[9] = 0; break;
+		case FEC_3_4:
+			cmd[9] = 1; break;
+		case FEC_3_5:
+			cmd[9] = 2; break;
+		case FEC_5_6:
+			cmd[9] = 3; break;
+		case FEC_8_9:
+			cmd[9] = 4; break;
+		default:
+			cmd[9] = 0; break;
+		}
+		break;
+	case QAM_16: /* QAM_16 is for compatibility with DN */
+		cmd[8] = ADV_MOD_TURBO_16QAM;
+		cmd[9] = 0;
+		break;
+	default: /* Unknown modulation */
+		dprintk("%s: unsupported modulation selected (%d)\n",
+			__func__, c->modulation);
+		return -EOPNOTSUPP;
+	}
+
+	if (st->is_rev1)
+		gp8psk_set_tuner_mode(fe, 0);
+	st->ops->out(st->priv, TUNE_8PSK, 0, 0, cmd, 10);
+
+	st->lock = 0;
+	st->next_status_check = jiffies;
+	st->status_check_interval = 200;
+
+	return 0;
+}
+
+static int gp8psk_fe_send_diseqc_msg (struct dvb_frontend* fe,
+				    struct dvb_diseqc_master_cmd *m)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+
+	dprintk("%s\n", __func__);
+
+	if (st->ops->out(st->priv, SEND_DISEQC_COMMAND, m->msg[0], 0,
+			m->msg, m->msg_len)) {
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int gp8psk_fe_send_diseqc_burst(struct dvb_frontend *fe,
+				       enum fe_sec_mini_cmd burst)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+	u8 cmd;
+
+	dprintk("%s\n", __func__);
+
+	/* These commands are certainly wrong */
+	cmd = (burst == SEC_MINI_A) ? 0x00 : 0x01;
+
+	if (st->ops->out(st->priv, SEND_DISEQC_COMMAND, cmd, 0,
+			&cmd, 0)) {
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int gp8psk_fe_set_tone(struct dvb_frontend *fe,
+			      enum fe_sec_tone_mode tone)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+
+	if (st->ops->out(st->priv, SET_22KHZ_TONE,
+			 (tone == SEC_TONE_ON), 0, NULL, 0)) {
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int gp8psk_fe_set_voltage(struct dvb_frontend *fe,
+				 enum fe_sec_voltage voltage)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+
+	if (st->ops->out(st->priv, SET_LNB_VOLTAGE,
+			 voltage == SEC_VOLTAGE_18, 0, NULL, 0)) {
+		return -EINVAL;
+	}
+	return 0;
+}
+
+static int gp8psk_fe_enable_high_lnb_voltage(struct dvb_frontend* fe, long onoff)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+
+	return st->ops->out(st->priv, USE_EXTRA_VOLT, onoff, 0, NULL, 0);
+}
+
+static int gp8psk_fe_send_legacy_dish_cmd (struct dvb_frontend* fe, unsigned long sw_cmd)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+	u8 cmd = sw_cmd & 0x7f;
+
+	if (st->ops->out(st->priv, SET_DN_SWITCH, cmd, 0, NULL, 0))
+		return -EINVAL;
+
+	if (st->ops->out(st->priv, SET_LNB_VOLTAGE, !!(sw_cmd & 0x80),
+			0, NULL, 0))
+		return -EINVAL;
+
+	return 0;
+}
+
+static void gp8psk_fe_release(struct dvb_frontend* fe)
+{
+	struct gp8psk_fe_state *st = fe->demodulator_priv;
+
+	kfree(st);
+}
+
+static struct dvb_frontend_ops gp8psk_fe_ops;
+
+struct dvb_frontend *gp8psk_fe_attach(const struct gp8psk_fe_ops *ops,
+				      void *priv, bool is_rev1)
+{
+	struct gp8psk_fe_state *st;
+
+	if (!ops || !ops->in || !ops->out || !ops->reload) {
+		pr_err("Error! gp8psk-fe ops not defined.\n");
+		return NULL;
+	}
+
+	st = kzalloc(sizeof(struct gp8psk_fe_state), GFP_KERNEL);
+	if (!st)
+		return NULL;
+
+	memcpy(&st->fe.ops, &gp8psk_fe_ops, sizeof(struct dvb_frontend_ops));
+	st->fe.demodulator_priv = st;
+	st->ops = ops;
+	st->priv = priv;
+	st->is_rev1 = is_rev1;
+
+	pr_info("Frontend %sattached\n", is_rev1 ? "revision 1 " : "");
+
+	return &st->fe;
+}
+EXPORT_SYMBOL_GPL(gp8psk_fe_attach);
+
+static struct dvb_frontend_ops gp8psk_fe_ops = {
+	.delsys = { SYS_DVBS },
+	.info = {
+		.name			= "Genpix DVB-S",
+		.frequency_min		= 800000,
+		.frequency_max		= 2250000,
+		.frequency_stepsize	= 100,
+		.symbol_rate_min        = 1000000,
+		.symbol_rate_max        = 45000000,
+		.symbol_rate_tolerance  = 500,  /* ppm */
+		.caps = FE_CAN_INVERSION_AUTO |
+			FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 |
+			FE_CAN_FEC_5_6 | FE_CAN_FEC_7_8 | FE_CAN_FEC_AUTO |
+			/*
+			 * FE_CAN_QAM_16 is for compatibility
+			 * (Myth incorrectly detects Turbo-QPSK as plain QAM-16)
+			 */
+			FE_CAN_QPSK | FE_CAN_QAM_16 | FE_CAN_TURBO_FEC
+	},
+
+	.release = gp8psk_fe_release,
+
+	.init = NULL,
+	.sleep = NULL,
+
+	.set_frontend = gp8psk_fe_set_frontend,
+
+	.get_tune_settings = gp8psk_fe_get_tune_settings,
+
+	.read_status = gp8psk_fe_read_status,
+	.read_ber = gp8psk_fe_read_ber,
+	.read_signal_strength = gp8psk_fe_read_signal_strength,
+	.read_snr = gp8psk_fe_read_snr,
+	.read_ucblocks = gp8psk_fe_read_unc_blocks,
+
+	.diseqc_send_master_cmd = gp8psk_fe_send_diseqc_msg,
+	.diseqc_send_burst = gp8psk_fe_send_diseqc_burst,
+	.set_tone = gp8psk_fe_set_tone,
+	.set_voltage = gp8psk_fe_set_voltage,
+	.dishnetwork_send_legacy_command = gp8psk_fe_send_legacy_dish_cmd,
+	.enable_high_lnb_voltage = gp8psk_fe_enable_high_lnb_voltage
+};
diff --git a/drivers/media/dvb-frontends/gp8psk-fe.h b/drivers/media/dvb-frontends/gp8psk-fe.h
new file mode 100644
index 000000000000..6c7944b1ecd6
--- /dev/null
+++ b/drivers/media/dvb-frontends/gp8psk-fe.h
@@ -0,0 +1,82 @@
+/*
+ * gp8psk_fe driver
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef GP8PSK_FE_H
+#define GP8PSK_FE_H
+
+#include <linux/types.h>
+
+/* gp8psk commands */
+
+#define GET_8PSK_CONFIG                 0x80    /* in */
+#define SET_8PSK_CONFIG                 0x81
+#define I2C_WRITE			0x83
+#define I2C_READ			0x84
+#define ARM_TRANSFER                    0x85
+#define TUNE_8PSK                       0x86
+#define GET_SIGNAL_STRENGTH             0x87    /* in */
+#define LOAD_BCM4500                    0x88
+#define BOOT_8PSK                       0x89    /* in */
+#define START_INTERSIL                  0x8A    /* in */
+#define SET_LNB_VOLTAGE                 0x8B
+#define SET_22KHZ_TONE                  0x8C
+#define SEND_DISEQC_COMMAND             0x8D
+#define SET_DVB_MODE                    0x8E
+#define SET_DN_SWITCH                   0x8F
+#define GET_SIGNAL_LOCK                 0x90    /* in */
+#define GET_FW_VERS			0x92
+#define GET_SERIAL_NUMBER               0x93    /* in */
+#define USE_EXTRA_VOLT                  0x94
+#define GET_FPGA_VERS			0x95
+#define CW3K_INIT			0x9d
+
+/* PSK_configuration bits */
+#define bm8pskStarted                   0x01
+#define bm8pskFW_Loaded                 0x02
+#define bmIntersilOn                    0x04
+#define bmDVBmode                       0x08
+#define bm22kHz                         0x10
+#define bmSEL18V                        0x20
+#define bmDCtuned                       0x40
+#define bmArmed                         0x80
+
+/* Satellite modulation modes */
+#define ADV_MOD_DVB_QPSK 0     /* DVB-S QPSK */
+#define ADV_MOD_TURBO_QPSK 1   /* Turbo QPSK */
+#define ADV_MOD_TURBO_8PSK 2   /* Turbo 8PSK (also used for Trellis 8PSK) */
+#define ADV_MOD_TURBO_16QAM 3  /* Turbo 16QAM (also used for Trellis 8PSK) */
+
+#define ADV_MOD_DCII_C_QPSK 4  /* Digicipher II Combo */
+#define ADV_MOD_DCII_I_QPSK 5  /* Digicipher II I-stream */
+#define ADV_MOD_DCII_Q_QPSK 6  /* Digicipher II Q-stream */
+#define ADV_MOD_DCII_C_OQPSK 7 /* Digicipher II offset QPSK */
+#define ADV_MOD_DSS_QPSK 8     /* DSS (DIRECTV) QPSK */
+#define ADV_MOD_DVB_BPSK 9     /* DVB-S BPSK */
+
+/* firmware revision id's */
+#define GP8PSK_FW_REV1			0x020604
+#define GP8PSK_FW_REV2			0x020704
+#define GP8PSK_FW_VERS(_fw_vers) \
+	((_fw_vers)[2]<<0x10 | (_fw_vers)[1]<<0x08 | (_fw_vers)[0])
+
+struct gp8psk_fe_ops {
+	int (*in)(void *priv, u8 req, u16 value, u16 index, u8 *b, int blen);
+	int (*out)(void *priv, u8 req, u16 value, u16 index, u8 *b, int blen);
+	int (*reload)(void *priv);
+};
+
+struct dvb_frontend *gp8psk_fe_attach(const struct gp8psk_fe_ops *ops,
+				      void *priv, bool is_rev1);
+
+#endif