Accessiblity: speakup_bns: specifying the default driver parameters among the module params

This is an enhancement which allows to specify the default driver
parameters among the module parameters.

Adding default variables to the speakup_bns module
allows to easily set that at boot, rather than
setting the sys variables after boot.
More details can be found here:
https://github.com/linux-speakup/speakup/issues/7

Signed-off-by: Osama Muhammad <[e-mail]>
Reviewed-by: Samuel Thibault <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/accessibility/speakup/speakup_bns.c

···
 #define SYNTH_CLEAR 0x18
 #define PROCSPEECH '\r'
 
-static struct var_t vars[] = {
-	{ CAPS_START, .u.s = {"\x05\x31\x32P" } },
-	{ CAPS_STOP, .u.s = {"\x05\x38P" } },
-	{ RATE, .u.n = {"\x05%dE", 8, 1, 16, 0, 0, NULL } },
-	{ PITCH, .u.n = {"\x05%dP", 8, 0, 16, 0, 0, NULL } },
-	{ VOL, .u.n = {"\x05%dV", 8, 0, 16, 0, 0, NULL } },
-	{ TONE, .u.n = {"\x05%dT", 8, 0, 16, 0, 0, NULL } },
-	{ DIRECT, .u.n = {NULL, 0, 0, 1, 0, 0, NULL } },
+
+enum default_vars_id {
+	CAPS_START_ID = 0, CAPS_STOP_ID,
+	RATE_ID, PITCH_ID,
+	VOL_ID, TONE_ID,
+	DIRECT_ID, V_LAST_VAR_ID,
+	NB_ID
+};
+
+static struct var_t vars[NB_ID] = {
+	[CAPS_START_ID] = { CAPS_START, .u.s = {"\x05\x31\x32P" } },
+	[CAPS_STOP_ID] = { CAPS_STOP, .u.s = {"\x05\x38P" } },
+	[RATE_ID] = { RATE, .u.n = {"\x05%dE", 8, 1, 16, 0, 0, NULL } },
+	[PITCH_ID] = { PITCH, .u.n = {"\x05%dP", 8, 0, 16, 0, 0, NULL } },
+	[VOL_ID] = { VOL, .u.n = {"\x05%dV", 8, 0, 16, 0, 0, NULL } },
+	[TONE_ID] = { TONE, .u.n = {"\x05%dT", 8, 0, 16, 0, 0, NULL } },
+	[DIRECT_ID] = { DIRECT, .u.n = {NULL, 0, 0, 1, 0, 0, NULL } },
 	V_LAST_VAR
 };
 
···
 module_param_named(ser, synth_bns.ser, int, 0444);
 module_param_named(dev, synth_bns.dev_name, charp, 0444);
 module_param_named(start, synth_bns.startup, short, 0444);
+module_param_named(rate, vars[RATE_ID].u.n.default_val, int, 0444);
+module_param_named(pitch, vars[PITCH_ID].u.n.default_val, int, 0444);
+module_param_named(vol, vars[VOL_ID].u.n.default_val, int, 0444);
+module_param_named(tone, vars[TONE_ID].u.n.default_val, int, 0444);
+module_param_named(direct, vars[DIRECT_ID].u.n.default_val, int, 0444);
+
 
 MODULE_PARM_DESC(ser, "Set the serial port for the synthesizer (0-based).");
 MODULE_PARM_DESC(dev, "Set the device e.g. ttyUSB0, for the synthesizer.");
 MODULE_PARM_DESC(start, "Start the synthesizer once it is loaded.");
+MODULE_PARM_DESC(rate, "Set the rate variable on load.");
+MODULE_PARM_DESC(pitch, "Set the pitch variable on load.");
+MODULE_PARM_DESC(vol, "Set the vol variable on load.");
+MODULE_PARM_DESC(tone, "Set the tone variable on load.");
+MODULE_PARM_DESC(direct, "Set the direct variable on load.");
 
 module_spk_synth(synth_bns);