TWxSoftware/twx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Input: i8042 - tease apart interrupt handler

Browse Source 
In preparation to using guard notation when acquiring mutexes and
spinlocks factor out handling of active multiplexing mode from
i8042_interrupt().

Link: https://lore.kernel.org/r/20240905041732.2034348-13-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Dmitry Torokhov
2024-09-04 21:17:17 -07:00
parent 79d01971fa
commit c374a0cdab
1 changed files with 89 additions and 62 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/input/serio/i8042.c
+89 -62
View File
@@ -178,7 +178,7 @@ static unsigned char i8042_suppress_kbd_ack;
static struct platform_device *i8042_platform_device;
static struct notifier_block i8042_kbd_bind_notifier_block;
static irqreturn_t i8042_interrupt(int irq, void *dev_id);
static bool i8042_handle_data(int irq);
static bool (*i8042_platform_filter)(unsigned char data, unsigned char str,
struct serio *serio);
@@ -434,7 +434,7 @@ static void i8042_port_close(struct serio *serio)
* See if there is any data appeared while we were messing with
* port state.
*/
i8042_interrupt(0, NULL);
i8042_handle_data(0);
}
/*
@@ -518,44 +518,10 @@ static bool i8042_filter(unsigned char data, unsigned char str,
}
/*
* i8042_interrupt() is the most important function in this driver -
* it handles the interrupts from the i8042, and sends incoming bytes
* to the upper layers.
*/
static irqreturn_t i8042_interrupt(int irq, void *dev_id)
{
struct i8042_port *port;
struct serio *serio;
unsigned long flags;
unsigned char str, data;
unsigned int dfl;
unsigned int port_no;
bool filtered;
int ret = 1;
spin_lock_irqsave(&i8042_lock, flags);
str = i8042_read_status();
if (unlikely(~str & I8042_STR_OBF)) {
spin_unlock_irqrestore(&i8042_lock, flags);
if (irq)
dbg("Interrupt %d, without any data\n", irq);
ret = 0;
goto out;
}
data = i8042_read_data();
if (i8042_mux_present && (str & I8042_STR_AUXDATA)) {
static unsigned long last_transmit;
static unsigned char last_str;
dfl = 0;
if (str & I8042_STR_MUXERR) {
dbg("MUX error, status is %02x, data is %02x\n",
str, data);
/*
* i8042_handle_mux() handles case when data is coming from one of
* the multiplexed ports. It would be simple if not for quirks with
* handling errors:
*
* When MUXERR condition is signalled the data register can only contain
* 0xfd, 0xfe or 0xff if implementation follows the spec. Unfortunately
* it is not always the case. Some KBCs also report 0xfc when there is
@@ -567,28 +533,79 @@ static irqreturn_t i8042_interrupt(int irq, void *dev_id)
* rest assume that the data came from the same serio last byte
* was transmitted (if transmission happened not too long ago).
*/
static int i8042_handle_mux(u8 str, u8 *data, unsigned int *dfl)
{
static unsigned long last_transmit;
static unsigned long last_port;
unsigned int mux_port;
switch (data) {
default:
if (time_before(jiffies, last_transmit + HZ/10)) {
str = last_str;
break;
}
fallthrough; /* report timeout */
case 0xfc:
case 0xfd:
case 0xfe: dfl = SERIO_TIMEOUT; data = 0xfe; break;
case 0xff: dfl = SERIO_PARITY; data = 0xfe; break;
mux_port = (str >> 6) & 3;
*dfl = 0;
if (str & I8042_STR_MUXERR) {
dbg("MUX error, status is %02x, data is %02x\n",
str, *data);
switch (*data) {
default:
if (time_before(jiffies, last_transmit + HZ/10)) {
mux_port = last_port;
break;
}
fallthrough; /* report timeout */
case 0xfc:
case 0xfd:
case 0xfe:
*dfl = SERIO_TIMEOUT;
*data = 0xfe;
break;
case 0xff:
*dfl = SERIO_PARITY;
*data = 0xfe;
break;
}
}
port_no = I8042_MUX_PORT_NO + ((str >> 6) & 3);
last_str = str;
last_transmit = jiffies;
last_port = mux_port;
last_transmit = jiffies;
return I8042_MUX_PORT_NO + mux_port;
}
/*
* i8042_handle_data() is the most important function in this driver -
* it reads the data from the i8042, determines its destination serio
* port, and sends received byte to the upper layers.
*
* Returns true if there was data waiting, false otherwise.
*/
static bool i8042_handle_data(int irq)
{
struct i8042_port *port;
struct serio *serio;
unsigned long flags;
unsigned char str, data;
unsigned int dfl;
unsigned int port_no;
bool filtered;
spin_lock_irqsave(&i8042_lock, flags);
str = i8042_read_status();
if (unlikely(~str & I8042_STR_OBF)) {
spin_unlock_irqrestore(&i8042_lock, flags);
return false;
}
data = i8042_read_data();
if (i8042_mux_present && (str & I8042_STR_AUXDATA)) {
port_no = i8042_handle_mux(str, &data, &dfl);
} else {
dfl = ((str & I8042_STR_PARITY) ? SERIO_PARITY : 0) |
((str & I8042_STR_TIMEOUT && !i8042_notimeout) ? SERIO_TIMEOUT : 0);
dfl = (str & I8042_STR_PARITY) ? SERIO_PARITY : 0;
if ((str & I8042_STR_TIMEOUT) && !i8042_notimeout)
dfl |= SERIO_TIMEOUT;
port_no = (str & I8042_STR_AUXDATA) ?
I8042_AUX_PORT_NO : I8042_KBD_PORT_NO;
@@ -609,8 +626,17 @@ static irqreturn_t i8042_interrupt(int irq, void *dev_id)
if (likely(serio && !filtered))
serio_interrupt(serio, data, dfl);
out:
return IRQ_RETVAL(ret);
return true;
}
static irqreturn_t i8042_interrupt(int irq, void *dev_id)
{
if (unlikely(!i8042_handle_data(irq))) {
dbg("Interrupt %d, without any data\n", irq);
return IRQ_NONE;
}
return IRQ_HANDLED;
}
/*
@@ -1216,13 +1242,14 @@ static int i8042_controller_resume(bool s2r_wants_reset)
if (i8042_mux_present) {
if (i8042_set_mux_mode(true, NULL) || i8042_enable_mux_ports())
pr_warn("failed to resume active multiplexor, mouse won't work\n");
} else if (i8042_ports[I8042_AUX_PORT_NO].serio)
} else if (i8042_ports[I8042_AUX_PORT_NO].serio) {
i8042_enable_aux_port();
}
if (i8042_ports[I8042_KBD_PORT_NO].serio)
i8042_enable_kbd_port();
i8042_interrupt(0, NULL);
i8042_handle_data(0);
return 0;
}
@@ -1253,7 +1280,7 @@ static int i8042_pm_suspend(struct device *dev)
static int i8042_pm_resume_noirq(struct device *dev)
{
if (i8042_forcenorestore || !pm_resume_via_firmware())
i8042_interrupt(0, NULL);
i8042_handle_data(0);
return 0;
}
@@ -1290,7 +1317,7 @@ static int i8042_pm_resume(struct device *dev)
static int i8042_pm_thaw(struct device *dev)
{
i8042_interrupt(0, NULL);
i8042_handle_data(0);
return 0;
}