V4L/DVB (8097): xc5000: check device hardware state to determine if firmware download is needed

This patch ensures that the xc5000 will have firmware loaded as needed if the
part is powered down or reset via gpio from the host. An example of this, in
some cases, could be after the system resumes from standby or hibernate modes.

Signed-off-by: Michael Krufky <mkrufky@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/common/tuners/xc5000.c b/drivers/media/common/tuners/xc5000.c
index ceae6db..7cf4f5b 100644
--- a/drivers/media/common/tuners/xc5000.c
+++ b/drivers/media/common/tuners/xc5000.c
@@ -177,6 +177,7 @@
 	{"FM Radio-INPUT1",   0x0208, 0x9002}
 };
 
+static int  xc5000_is_firmware_loaded(struct dvb_frontend *fe);
 static int  xc5000_writeregs(struct xc5000_priv *priv, u8 *buf, u8 len);
 static int  xc5000_readregs(struct xc5000_priv *priv, u8 *buf, u8 len);
 static void xc5000_TunerReset(struct dvb_frontend *fe);
@@ -352,7 +353,7 @@
 
 static int xc_shutdown(struct xc5000_priv *priv)
 {
-	return 0;
+	return XC_RESULT_SUCCESS;
 	/* Fixme: cannot bring tuner back alive once shutdown
 	 *        without reloading the driver modules.
 	 *    return xc_write_reg(priv, XREG_POWER_DOWN, 0);
@@ -685,6 +686,25 @@
 	return 0;
 }
 
+static int xc5000_is_firmware_loaded(struct dvb_frontend *fe)
+{
+	struct xc5000_priv *priv = fe->tuner_priv;
+	int ret;
+	u16 id;
+
+	ret = xc5000_readreg(priv, XREG_PRODUCT_ID, &id);
+	if (ret == XC_RESULT_SUCCESS) {
+		if (id == XC_PRODUCT_ID_FW_NOT_LOADED)
+			ret = XC_RESULT_RESET_FAILURE;
+		else
+			ret = XC_RESULT_SUCCESS;
+	}
+
+	dprintk(1, "%s() returns %s id = 0x%x\n", __func__,
+		ret == XC_RESULT_SUCCESS ? "True" : "False", id);
+	return ret;
+}
+
 static int xc_load_fw_and_init_tuner(struct dvb_frontend *fe);
 
 static int xc5000_set_analog_params(struct dvb_frontend *fe,
@@ -693,7 +713,7 @@
 	struct xc5000_priv *priv = fe->tuner_priv;
 	int ret;
 
-	if(priv->fwloaded == 0)
+	if (xc5000_is_firmware_loaded(fe) != XC_RESULT_SUCCESS)
 		xc_load_fw_and_init_tuner(fe);
 
 	dprintk(1, "%s() frequency=%d (in units of 62.5khz)\n",
@@ -808,11 +828,10 @@
 	struct xc5000_priv *priv = fe->tuner_priv;
 	int ret = 0;
 
-	if (priv->fwloaded == 0) {
+	if (xc5000_is_firmware_loaded(fe) != XC_RESULT_SUCCESS) {
 		ret = xc5000_fwupload(fe);
 		if (ret != XC_RESULT_SUCCESS)
 			return ret;
-		priv->fwloaded = 1;
 	}
 
 	/* Start the tuner self-calibration process */
@@ -852,7 +871,6 @@
 		return -EREMOTEIO;
 	}
 	else {
-		/* priv->fwloaded = 0; */
 		return XC_RESULT_SUCCESS;
 	}
 }
@@ -933,7 +951,6 @@
 			cfg->i2c_address);
 		printk(KERN_INFO
 			"xc5000: Firmware has been loaded previously\n");
-		priv->fwloaded = 1;
 		break;
 	case XC_PRODUCT_ID_FW_NOT_LOADED:
 		printk(KERN_INFO
@@ -941,7 +958,6 @@
 			cfg->i2c_address);
 		printk(KERN_INFO
 			"xc5000: Firmware has not been loaded previously\n");
-		priv->fwloaded = 0;
 		break;
 	default:
 		printk(KERN_ERR