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Subject[PATCH v2 3/4] tty/nozomi: improve code readability and style
Date
Improve code clarity by renaming identifiers and reorganizing
function control flow.

Signed-off-by: Joey Pabalinas <joeypabalinas@gmail.com>

1 file changed, 92 insertions(+), 91 deletions(-)

1 file changed, 76 insertions(+), 90 deletions(-)

diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
index 0fcb4db721d2a42f08..a5074a59d3e3d33e68 100644
--- a/drivers/tty/nozomi.c
+++ b/drivers/tty/nozomi.c
@@ -401,7 +401,7 @@ static inline struct port *get_port_by_tty(const struct tty_struct *tty)
static void read_mem32(u32 *buf, const void __iomem *mem_addr_start,
u32 size_bytes)
{
- u32 i = 0;
+ u32 nread = 0;
const u32 __iomem *ptr = mem_addr_start;
u16 *buf16;

@@ -411,30 +411,27 @@ static void read_mem32(u32 *buf, const void __iomem *mem_addr_start,
/* shortcut for extremely often used cases */
switch (size_bytes) {
case 2: /* 2 bytes */
- buf16 = (u16 *) buf;
+ buf16 = (u16 *)buf;
*buf16 = __le16_to_cpu(readw(ptr));
goto out;
- break;
case 4: /* 4 bytes */
- *(buf) = __le32_to_cpu(readl(ptr));
+ *buf = __le32_to_cpu(readl(ptr));
goto out;
- break;
}

- while (i < size_bytes) {
- if (size_bytes - i == 2) {
+ for (; nread < size_bytes; buf++, ptr++) {
+ if (size_bytes - nread == 2) {
/* Handle 2 bytes in the end */
- buf16 = (u16 *) buf;
- *(buf16) = __le16_to_cpu(readw(ptr));
- i += 2;
+ buf16 = (u16 *)buf;
+ *buf16 = __le16_to_cpu(readw(ptr));
+ nread += 2;
} else {
/* Read 4 bytes */
- *(buf) = __le32_to_cpu(readl(ptr));
- i += 4;
+ *buf = __le32_to_cpu(readl(ptr));
+ nread += 4;
}
- buf++;
- ptr++;
}
+
out:
return;
}
@@ -447,7 +444,7 @@ static void read_mem32(u32 *buf, const void __iomem *mem_addr_start,
static u32 write_mem32(void __iomem *mem_addr_start, const u32 *buf,
u32 size_bytes)
{
- u32 i = 0;
+ u32 nwritten = 0;
u32 __iomem *ptr = mem_addr_start;
const u16 *buf16;

@@ -460,7 +457,6 @@ static u32 write_mem32(void __iomem *mem_addr_start, const u32 *buf,
buf16 = (const u16 *)buf;
writew(__cpu_to_le16(*buf16), ptr);
return 2;
- break;
case 1: /*
* also needs to write 4 bytes in this case
* so falling through..
@@ -468,24 +464,22 @@ static u32 write_mem32(void __iomem *mem_addr_start, const u32 *buf,
case 4: /* 4 bytes */
writel(__cpu_to_le32(*buf), ptr);
return 4;
- break;
}

- while (i < size_bytes) {
- if (size_bytes - i == 2) {
+ for (; nwritten < size_bytes; buf++, ptr++) {
+ if (size_bytes - nwritten == 2) {
/* 2 bytes */
buf16 = (const u16 *)buf;
writew(__cpu_to_le16(*buf16), ptr);
- i += 2;
+ nwritten += 2;
} else {
/* 4 bytes */
writel(__cpu_to_le32(*buf), ptr);
- i += 4;
+ nwritten += 4;
}
- buf++;
- ptr++;
}
- return i;
+
+ return nwritten;
}

/* Setup pointers to different channels and also setup buffer sizes. */
@@ -632,9 +626,10 @@ static int nozomi_read_config_table(struct nozomi *dc)
return 0;
}

- if ((dc->config_table.version == 0)
- || (dc->config_table.toggle.enabled == TOGGLE_VALID)) {
+ if (!dc->config_table.version
+ || dc->config_table.toggle.enabled == TOGGLE_VALID) {
int i;
+
DBG1("Second phase, configuring card");

nozomi_setup_memory(dc);
@@ -659,12 +654,14 @@ static int nozomi_read_config_table(struct nozomi *dc)

dc->state = NOZOMI_STATE_ALLOCATED;
dev_info(&dc->pdev->dev, "Initialization OK!\n");
+
return 1;
}

- if ((dc->config_table.version > 0)
- && (dc->config_table.toggle.enabled != TOGGLE_VALID)) {
+ if (dc->config_table.version > 0
+ && dc->config_table.toggle.enabled != TOGGLE_VALID) {
u32 offset = 0;
+
DBG1("First phase: pushing upload buffers, clearing download");

dev_info(&dc->pdev->dev, "Version of card: %d\n",
@@ -752,7 +749,7 @@ static void disable_transmit_dl(enum port_type port, struct nozomi *dc)
*/
static int send_data(enum port_type index, struct nozomi *dc)
{
- u32 size = 0;
+ u32 size;
struct port *port = &dc->port[index];
const u8 toggle = port->toggle_ul;
void __iomem *addr = port->ul_addr[toggle];
@@ -762,7 +759,7 @@ static int send_data(enum port_type index, struct nozomi *dc)
size = kfifo_out(&port->fifo_ul, dc->send_buf,
ul_size < SEND_BUF_MAX ? ul_size : SEND_BUF_MAX);

- if (size == 0) {
+ if (!size) {
DBG4("No more data to send, disable link:");
return 0;
}
@@ -770,8 +767,8 @@ static int send_data(enum port_type index, struct nozomi *dc)
/* DUMP(buf, size); */

/* Write length + data */
- write_mem32(addr, (u32 *) &size, 4);
- write_mem32(addr + 4, (u32 *) dc->send_buf, size);
+ write_mem32(addr, (u32 *)&size, 4);
+ write_mem32(addr + 4, (u32 *)dc->send_buf, size);

tty_port_tty_wakeup(&port->port);

@@ -781,13 +778,12 @@ static int send_data(enum port_type index, struct nozomi *dc)
/* If all data has been read, return 1, else 0 */
static int receive_data(enum port_type index, struct nozomi *dc)
{
- u8 buf[RECEIVE_BUF_MAX] = { 0 };
- int size;
+ u8 buf[RECEIVE_BUF_MAX] = {0};
u32 offset = 4;
struct port *port = &dc->port[index];
void __iomem *addr = port->dl_addr[port->toggle_dl];
struct tty_struct *tty = tty_port_tty_get(&port->port);
- int i, ret;
+ int size, ret, i;

size = __le32_to_cpu(readl(addr));
/* DBG1( "%d bytes port: %d", size, index); */
@@ -802,14 +798,14 @@ static int receive_data(enum port_type index, struct nozomi *dc)
goto put;
}

- if (unlikely(size == 0)) {
+ if (unlikely(!size)) {
dev_err(&dc->pdev->dev, "size == 0?\n");
ret = 1;
goto put;
}

while (size > 0) {
- read_mem32((u32 *) buf, addr + offset, RECEIVE_BUF_MAX);
+ read_mem32((u32 *)buf, addr + offset, RECEIVE_BUF_MAX);

if (size == 1) {
tty_insert_flip_char(&port->port, buf[0], TTY_NORMAL);
@@ -937,9 +933,7 @@ static int receive_flow_control(struct nozomi *dc)
DBG1("Disable interrupt (0x%04X) on port: %d",
enable_ier, port);
disable_transmit_ul(port, dc);
-
} else if (old_ctrl.CTS == 0 && ctrl_dl.CTS == 1) {
-
if (kfifo_len(&dc->port[port].fifo_ul)) {
DBG1("Enable interrupt (0x%04X) on port: %d",
enable_ier, port);
@@ -989,7 +983,7 @@ static enum ctrl_port_type port2ctrl(enum port_type port,
return CTRL_APP2;
default:
dev_err(&dc->pdev->dev,
- "ERROR: send flow control " \
+ "ERROR: send flow control "
"received for non-existing port\n");
}
return CTRL_ERROR;
@@ -1002,23 +996,24 @@ static enum ctrl_port_type port2ctrl(enum port_type port,
*/
static int send_flow_control(struct nozomi *dc)
{
- u32 i, more_flow_control_to_be_updated = 0;
+ u32 more_flow_control_to_be_updated = 0;
+ u32 i;
u16 *ctrl;

for (i = PORT_MDM; i < MAX_PORT; i++) {
if (dc->port[i].update_flow_control) {
- if (more_flow_control_to_be_updated) {
- /* We have more flow control to be updated */
+ if (more_flow_control_to_be_updated)
return 1;
- }
+
dc->port[i].ctrl_ul.port = port2ctrl(i, dc);
ctrl = (u16 *)&dc->port[i].ctrl_ul;
- write_mem32(dc->port[PORT_CTRL].ul_addr[0], \
- (u32 *) ctrl, 2);
+ write_mem32(dc->port[PORT_CTRL].ul_addr[0],
+ (u32 *)ctrl, 2);
dc->port[i].update_flow_control = 0;
more_flow_control_to_be_updated = 1;
}
}
+
return 0;
}

@@ -1069,7 +1064,7 @@ static int handle_data_dl(struct nozomi *dc, enum port_type port, u8 *toggle,
*/
static int handle_data_ul(struct nozomi *dc, enum port_type port, u16 read_iir)
{
- u8 *toggle = &(dc->port[port].toggle_ul);
+ u8 *toggle = &dc->port[port].toggle_ul;

if (*toggle == 0 && read_iir & MDM_UL1) {
dc->last_ier &= ~MDM_UL;
@@ -1123,7 +1118,7 @@ static int handle_data_ul(struct nozomi *dc, enum port_type port, u16 read_iir)
static irqreturn_t interrupt_handler(int irq, void *dev_id)
{
struct nozomi *dc = dev_id;
- unsigned int a;
+ unsigned int i;
u16 read_iir;

if (!dc)
@@ -1141,10 +1136,9 @@ static irqreturn_t interrupt_handler(int irq, void *dev_id)
*/
read_iir &= dc->last_ier;

- if (read_iir == 0)
+ if (!read_iir)
goto none;

-
DBG4("%s irq:0x%04X, prev:0x%04X", interrupt2str(read_iir), read_iir,
dc->last_ier);

@@ -1235,9 +1229,9 @@ static irqreturn_t interrupt_handler(int irq, void *dev_id)
exit_handler:
spin_unlock(&dc->spin_mutex);

- for (a = 0; a < NOZOMI_MAX_PORTS; a++)
- if (test_and_clear_bit(a, &dc->flip))
- tty_flip_buffer_push(&dc->port[a].port);
+ for (i = 0; i < NOZOMI_MAX_PORTS; i++)
+ if (test_and_clear_bit(i, &dc->flip))
+ tty_flip_buffer_push(&dc->port[i].port);

return IRQ_HANDLED;
none:
@@ -1318,10 +1312,8 @@ static int nozomi_card_init(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
resource_size_t start;
- int ret;
- struct nozomi *dc = NULL;
- int ndev_idx;
- int i;
+ struct nozomi *dc;
+ int ndev_idx, ret, i;

dev_dbg(&pdev->dev, "Init, new card found\n");

@@ -1352,8 +1344,8 @@ static int nozomi_card_init(struct pci_dev *pdev,

ret = pci_request_regions(dc->pdev, NOZOMI_NAME);
if (ret) {
- dev_err(&pdev->dev, "I/O address 0x%04x already in use\n",
- (int) /* nozomi_private.io_addr */ 0);
+ /* nozomi_private.io_addr */
+ dev_err(&pdev->dev, "I/O address 0x%04x already in use\n", 0);
goto err_disable_device;
}

@@ -1429,19 +1421,18 @@ static int nozomi_card_init(struct pci_dev *pdev,
port->port.ops = &noz_tty_port_ops;
tty_dev = tty_port_register_device(&port->port, ntty_driver,
dc->index_start + i, &pdev->dev);
+ if (likely(!IS_ERR(tty_dev)))
+ continue;

- if (IS_ERR(tty_dev)) {
- ret = PTR_ERR(tty_dev);
- dev_err(&pdev->dev, "Could not allocate tty?\n");
- tty_port_destroy(&port->port);
- goto err_free_tty;
- }
+ ret = PTR_ERR(tty_dev);
+ dev_err(&pdev->dev, "Could not allocate tty?\n");
+ tty_port_destroy(&port->port);
+ goto err_free_tty;
}

return 0;
-
err_free_tty:
- for (i = 0; i < MAX_PORT; ++i) {
+ for (i = 0; i < MAX_PORT; i++) {
tty_unregister_device(ntty_driver, dc->index_start + i);
tty_port_destroy(&dc->port[i].port);
}
@@ -1463,18 +1454,19 @@ static int nozomi_card_init(struct pci_dev *pdev,

static void tty_exit(struct nozomi *dc)
{
- unsigned int i;
+ int i;

DBG1(" ");

- for (i = 0; i < MAX_PORT; ++i)
+ for (i = 0; i < MAX_PORT; i++)
tty_port_tty_hangup(&dc->port[i].port, false);

/* Racy below - surely should wait for scheduled work to be done or
complete off a hangup method ? */
while (dc->open_ttys)
msleep(1);
- for (i = 0; i < MAX_PORT; ++i) {
+
+ for (i = 0; i < MAX_PORT; i++) {
tty_unregister_device(ntty_driver, dc->index_start + i);
tty_port_destroy(&dc->port[i].port);
}
@@ -1483,9 +1475,9 @@ static void tty_exit(struct nozomi *dc)
/* Deallocate memory for one device */
static void nozomi_card_exit(struct pci_dev *pdev)
{
- int i;
- struct ctrl_ul ctrl;
struct nozomi *dc = pci_get_drvdata(pdev);
+ struct ctrl_ul ctrl;
+ int i;

/* Disable all interrupts */
dc->last_ier = 0;
@@ -1559,7 +1551,7 @@ static int ntty_install(struct tty_driver *driver, struct tty_struct *tty)
if (!port || !dc || dc->state != NOZOMI_STATE_READY)
return -ENODEV;
ret = tty_standard_install(driver, tty);
- if (ret == 0)
+ if (!ret)
tty->driver_data = port;
return ret;
}
@@ -1599,7 +1591,7 @@ static void ntty_shutdown(struct tty_port *tport)

DBG1("close: %d", port->token_dl);
spin_lock_irqsave(&dc->spin_mutex, flags);
- dc->last_ier &= ~(port->token_dl);
+ dc->last_ier &= ~port->token_dl;
writew(dc->last_ier, dc->reg_ier);
dc->open_ttys--;
spin_unlock_irqrestore(&dc->spin_mutex, flags);
@@ -1626,21 +1618,21 @@ static void ntty_hangup(struct tty_struct *tty)
static int ntty_write(struct tty_struct *tty, const unsigned char *buffer,
int count)
{
- int rval = -EINVAL;
struct nozomi *dc = get_dc_by_tty(tty);
struct port *port = tty->driver_data;
unsigned long flags;
+ int rval;

/* DBG1( "WRITEx: %d, index = %d", count, index); */

- if (!dc || !port)
+ if (unlikely(!dc || !port))
return -ENODEV;

rval = kfifo_in(&port->fifo_ul, (unsigned char *)buffer, count);

spin_lock_irqsave(&dc->spin_mutex, flags);
/* CTS is only valid on the modem channel */
- if (port == &(dc->port[PORT_MDM])) {
+ if (port == &dc->port[PORT_MDM]) {
if (port->ctrl_dl.CTS) {
DBG4("Enable interrupt");
enable_transmit_ul(tty->index % MAX_PORT, dc);
@@ -1668,13 +1660,12 @@ static int ntty_write(struct tty_struct *tty, const unsigned char *buffer,
static int ntty_write_room(struct tty_struct *tty)
{
struct port *port = tty->driver_data;
- int room = 4096;
const struct nozomi *dc = get_dc_by_tty(tty);

- if (dc)
- room = kfifo_avail(&port->fifo_ul);
+ if (unlikely(!dc))
+ return 4096;

- return room;
+ return kfifo_avail(&port->fifo_ul);
}

/* Gets io control parameters */
@@ -1749,6 +1740,7 @@ static int ntty_tiocgicount(struct tty_struct *tty,
icount->parity = cnow.parity;
icount->brk = cnow.brk;
icount->buf_overrun = cnow.buf_overrun;
+
return 0;
}

@@ -1763,7 +1755,6 @@ static int ntty_ioctl(struct tty_struct *tty,
switch (cmd) {
case TIOCMIWAIT: {
struct async_icount cprev = port->tty_icount;
-
rval = wait_event_interruptible(port->tty_wait,
ntty_cflags_changed(port, arg, &cprev));
break;
@@ -1813,16 +1804,11 @@ static s32 ntty_chars_in_buffer(struct tty_struct *tty)
{
struct port *port = tty->driver_data;
struct nozomi *dc = get_dc_by_tty(tty);
- s32 rval = 0;

- if (unlikely(!dc || !port)) {
- goto exit_in_buffer;
- }
+ if (unlikely(!dc || !port))
+ return 0;

- rval = kfifo_len(&port->fifo_ul);
-
-exit_in_buffer:
- return rval;
+ return kfifo_len(&port->fifo_ul);
}

static const struct tty_port_operations noz_tty_port_ops = {
--
2.16.3
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