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Diffstat (limited to 'drivers/tty/serial/sc16is7xx.c')
-rw-r--r--drivers/tty/serial/sc16is7xx.c252
1 files changed, 120 insertions, 132 deletions
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index dba25e7090..929206a9a6 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -29,6 +29,7 @@
#define SC16IS7XX_NAME "sc16is7xx"
#define SC16IS7XX_MAX_DEVS 8
+#define SC16IS7XX_MAX_PORTS 2 /* Maximum number of UART ports per IC. */
/* SC16IS7XX register definitions */
#define SC16IS7XX_RHR_REG (0x00) /* RX FIFO */
@@ -329,8 +330,9 @@ struct sc16is7xx_one {
struct kthread_work reg_work;
struct kthread_delayed_work ms_work;
struct sc16is7xx_one_config config;
- bool irda_mode;
unsigned int old_mctrl;
+ u8 old_lcr; /* Value before EFR access. */
+ bool irda_mode;
};
struct sc16is7xx_port {
@@ -347,17 +349,15 @@ struct sc16is7xx_port {
struct sc16is7xx_one p[];
};
-static unsigned long sc16is7xx_lines;
+static DECLARE_BITMAP(sc16is7xx_lines, SC16IS7XX_MAX_DEVS);
static struct uart_driver sc16is7xx_uart = {
.owner = THIS_MODULE,
+ .driver_name = SC16IS7XX_NAME,
.dev_name = "ttySC",
.nr = SC16IS7XX_MAX_DEVS,
};
-static void sc16is7xx_ier_set(struct uart_port *port, u8 bit);
-static void sc16is7xx_stop_tx(struct uart_port *port);
-
#define to_sc16is7xx_one(p,e) ((container_of((p), struct sc16is7xx_one, e)))
static u8 sc16is7xx_port_read(struct uart_port *port, u8 reg)
@@ -377,17 +377,15 @@ static void sc16is7xx_port_write(struct uart_port *port, u8 reg, u8 val)
regmap_write(one->regmap, reg, val);
}
-static void sc16is7xx_fifo_read(struct uart_port *port, unsigned int rxlen)
+static void sc16is7xx_fifo_read(struct uart_port *port, u8 *rxbuf, unsigned int rxlen)
{
- struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
- regmap_noinc_read(one->regmap, SC16IS7XX_RHR_REG, s->buf, rxlen);
+ regmap_noinc_read(one->regmap, SC16IS7XX_RHR_REG, rxbuf, rxlen);
}
-static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
+static void sc16is7xx_fifo_write(struct uart_port *port, u8 *txbuf, u8 to_send)
{
- struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
/*
@@ -397,7 +395,7 @@ static void sc16is7xx_fifo_write(struct uart_port *port, u8 to_send)
if (unlikely(!to_send))
return;
- regmap_noinc_write(one->regmap, SC16IS7XX_THR_REG, s->buf, to_send);
+ regmap_noinc_write(one->regmap, SC16IS7XX_THR_REG, txbuf, to_send);
}
static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
@@ -415,6 +413,85 @@ static void sc16is7xx_power(struct uart_port *port, int on)
on ? 0 : SC16IS7XX_IER_SLEEP_BIT);
}
+/*
+ * In an amazing feat of design, the Enhanced Features Register (EFR)
+ * shares the address of the Interrupt Identification Register (IIR).
+ * Access to EFR is switched on by writing a magic value (0xbf) to the
+ * Line Control Register (LCR). Any interrupt firing during this time will
+ * see the EFR where it expects the IIR to be, leading to
+ * "Unexpected interrupt" messages.
+ *
+ * Prevent this possibility by claiming a mutex while accessing the EFR,
+ * and claiming the same mutex from within the interrupt handler. This is
+ * similar to disabling the interrupt, but that doesn't work because the
+ * bulk of the interrupt processing is run as a workqueue job in thread
+ * context.
+ */
+static void sc16is7xx_efr_lock(struct uart_port *port)
+{
+ struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+ mutex_lock(&one->efr_lock);
+
+ /* Backup content of LCR. */
+ one->old_lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
+
+ /* Enable access to Enhanced register set */
+ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, SC16IS7XX_LCR_CONF_MODE_B);
+
+ /* Disable cache updates when writing to EFR registers */
+ regcache_cache_bypass(one->regmap, true);
+}
+
+static void sc16is7xx_efr_unlock(struct uart_port *port)
+{
+ struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+ /* Re-enable cache updates when writing to normal registers */
+ regcache_cache_bypass(one->regmap, false);
+
+ /* Restore original content of LCR */
+ sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, one->old_lcr);
+
+ mutex_unlock(&one->efr_lock);
+}
+
+static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
+{
+ struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+ struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+ lockdep_assert_held_once(&port->lock);
+
+ one->config.flags |= SC16IS7XX_RECONF_IER;
+ one->config.ier_mask |= bit;
+ one->config.ier_val &= ~bit;
+ kthread_queue_work(&s->kworker, &one->reg_work);
+}
+
+static void sc16is7xx_ier_set(struct uart_port *port, u8 bit)
+{
+ struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+ struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+ lockdep_assert_held_once(&port->lock);
+
+ one->config.flags |= SC16IS7XX_RECONF_IER;
+ one->config.ier_mask |= bit;
+ one->config.ier_val |= bit;
+ kthread_queue_work(&s->kworker, &one->reg_work);
+}
+
+static void sc16is7xx_stop_tx(struct uart_port *port)
+{
+ sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
+}
+
+static void sc16is7xx_stop_rx(struct uart_port *port)
+{
+ sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
+}
+
static const struct sc16is7xx_devtype sc16is74x_devtype = {
.name = "SC16IS74X",
.nr_gpio = 0,
@@ -458,10 +535,8 @@ static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg)
case SC16IS7XX_IOCONTROL_REG:
return true;
default:
- break;
+ return false;
}
-
- return false;
}
static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
@@ -470,10 +545,8 @@ static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
case SC16IS7XX_RHR_REG:
return true;
default:
- break;
+ return false;
}
-
- return false;
}
static bool sc16is7xx_regmap_noinc(struct device *dev, unsigned int reg)
@@ -488,50 +561,24 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
u8 prescaler = 0;
unsigned long clk = port->uartclk, div = clk / 16 / baud;
- if (div > 0xffff) {
+ if (div >= BIT(16)) {
prescaler = SC16IS7XX_MCR_CLKSEL_BIT;
div /= 4;
}
- /* In an amazing feat of design, the Enhanced Features Register shares
- * the address of the Interrupt Identification Register, and is
- * switched in by writing a magic value (0xbf) to the Line Control
- * Register. Any interrupt firing during this time will see the EFR
- * where it expects the IIR to be, leading to "Unexpected interrupt"
- * messages.
- *
- * Prevent this possibility by claiming a mutex while accessing the
- * EFR, and claiming the same mutex from within the interrupt handler.
- * This is similar to disabling the interrupt, but that doesn't work
- * because the bulk of the interrupt processing is run as a workqueue
- * job in thread context.
- */
- mutex_lock(&one->efr_lock);
-
- lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
-
- /* Open the LCR divisors for configuration */
- sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
- SC16IS7XX_LCR_CONF_MODE_B);
-
/* Enable enhanced features */
- regcache_cache_bypass(one->regmap, true);
+ sc16is7xx_efr_lock(port);
sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
SC16IS7XX_EFR_ENABLE_BIT,
SC16IS7XX_EFR_ENABLE_BIT);
-
- regcache_cache_bypass(one->regmap, false);
-
- /* Put LCR back to the normal mode */
- sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
-
- mutex_unlock(&one->efr_lock);
+ sc16is7xx_efr_unlock(port);
sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
SC16IS7XX_MCR_CLKSEL_BIT,
prescaler);
- /* Open the LCR divisors for configuration */
+ /* Backup LCR and access special register set (DLL/DLH) */
+ lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
SC16IS7XX_LCR_CONF_MODE_A);
@@ -541,7 +588,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
sc16is7xx_port_write(port, SC16IS7XX_DLL_REG, div % 256);
regcache_cache_bypass(one->regmap, false);
- /* Put LCR back to the normal mode */
+ /* Restore LCR and access to general register set */
sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
return DIV_ROUND_CLOSEST(clk / 16, div);
@@ -577,7 +624,7 @@ static void sc16is7xx_handle_rx(struct uart_port *port, unsigned int rxlen,
s->buf[0] = sc16is7xx_port_read(port, SC16IS7XX_RHR_REG);
bytes_read = 1;
} else {
- sc16is7xx_fifo_read(port, rxlen);
+ sc16is7xx_fifo_read(port, s->buf, rxlen);
bytes_read = rxlen;
}
@@ -650,7 +697,7 @@ static void sc16is7xx_handle_tx(struct uart_port *port)
/* Get length of data pending in circular buffer */
to_send = uart_circ_chars_pending(xmit);
if (likely(to_send)) {
- /* Limit to size of TX FIFO */
+ /* Limit to space available in TX FIFO */
txlen = sc16is7xx_port_read(port, SC16IS7XX_TXLVL_REG);
if (txlen > SC16IS7XX_FIFO_SIZE) {
dev_err_ratelimited(port->dev,
@@ -666,7 +713,7 @@ static void sc16is7xx_handle_tx(struct uart_port *port)
uart_xmit_advance(port, 1);
}
- sc16is7xx_fifo_write(port, to_send);
+ sc16is7xx_fifo_write(port, s->buf, to_send);
}
uart_port_lock_irqsave(port, &flags);
@@ -871,42 +918,6 @@ static void sc16is7xx_reg_proc(struct kthread_work *ws)
sc16is7xx_reconf_rs485(&one->port);
}
-static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
-{
- struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
- struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
-
- lockdep_assert_held_once(&port->lock);
-
- one->config.flags |= SC16IS7XX_RECONF_IER;
- one->config.ier_mask |= bit;
- one->config.ier_val &= ~bit;
- kthread_queue_work(&s->kworker, &one->reg_work);
-}
-
-static void sc16is7xx_ier_set(struct uart_port *port, u8 bit)
-{
- struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
- struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
-
- lockdep_assert_held_once(&port->lock);
-
- one->config.flags |= SC16IS7XX_RECONF_IER;
- one->config.ier_mask |= bit;
- one->config.ier_val |= bit;
- kthread_queue_work(&s->kworker, &one->reg_work);
-}
-
-static void sc16is7xx_stop_tx(struct uart_port *port)
-{
- sc16is7xx_ier_clear(port, SC16IS7XX_IER_THRI_BIT);
-}
-
-static void sc16is7xx_stop_rx(struct uart_port *port)
-{
- sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT);
-}
-
static void sc16is7xx_ms_proc(struct kthread_work *ws)
{
struct sc16is7xx_one *one = to_sc16is7xx_one(ws, ms_work.work);
@@ -1056,17 +1067,7 @@ static void sc16is7xx_set_termios(struct uart_port *port,
if (!(termios->c_cflag & CREAD))
port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
- /* As above, claim the mutex while accessing the EFR. */
- mutex_lock(&one->efr_lock);
-
- sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
- SC16IS7XX_LCR_CONF_MODE_B);
-
/* Configure flow control */
- regcache_cache_bypass(one->regmap, true);
- sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
- sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
-
port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
if (termios->c_cflag & CRTSCTS) {
flow |= SC16IS7XX_EFR_AUTOCTS_BIT |
@@ -1078,16 +1079,16 @@ static void sc16is7xx_set_termios(struct uart_port *port,
if (termios->c_iflag & IXOFF)
flow |= SC16IS7XX_EFR_SWFLOW1_BIT;
- sc16is7xx_port_update(port,
- SC16IS7XX_EFR_REG,
- SC16IS7XX_EFR_FLOWCTRL_BITS,
- flow);
- regcache_cache_bypass(one->regmap, false);
-
/* Update LCR register */
sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
- mutex_unlock(&one->efr_lock);
+ /* Update EFR registers */
+ sc16is7xx_efr_lock(port);
+ sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]);
+ sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]);
+ sc16is7xx_port_update(port, SC16IS7XX_EFR_REG,
+ SC16IS7XX_EFR_FLOWCTRL_BITS, flow);
+ sc16is7xx_efr_unlock(port);
/* Get baud rate generator configuration */
baud = uart_get_baud_rate(port, termios, old,
@@ -1397,7 +1398,7 @@ static void sc16is7xx_setup_irda_ports(struct sc16is7xx_port *s)
int i;
int ret;
int count;
- u32 irda_port[2];
+ u32 irda_port[SC16IS7XX_MAX_PORTS];
struct device *dev = s->p[0].port.dev;
count = device_property_count_u32(dev, "irda-mode-ports");
@@ -1424,7 +1425,7 @@ static int sc16is7xx_setup_mctrl_ports(struct sc16is7xx_port *s,
int i;
int ret;
int count;
- u32 mctrl_port[2];
+ u32 mctrl_port[SC16IS7XX_MAX_PORTS];
struct device *dev = s->p[0].port.dev;
count = device_property_count_u32(dev, "nxp,modem-control-line-ports");
@@ -1536,7 +1537,7 @@ static int sc16is7xx_probe(struct device *dev,
SC16IS7XX_IOCONTROL_SRESET_BIT);
for (i = 0; i < devtype->nr_uart; ++i) {
- s->p[i].port.line = find_first_zero_bit(&sc16is7xx_lines,
+ s->p[i].port.line = find_first_zero_bit(sc16is7xx_lines,
SC16IS7XX_MAX_DEVS);
if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) {
ret = -ERANGE;
@@ -1587,7 +1588,7 @@ static int sc16is7xx_probe(struct device *dev,
if (ret)
goto out_ports;
- set_bit(s->p[i].port.line, &sc16is7xx_lines);
+ set_bit(s->p[i].port.line, sc16is7xx_lines);
/* Enable EFR */
sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG,
@@ -1646,7 +1647,7 @@ static int sc16is7xx_probe(struct device *dev,
out_ports:
for (i = 0; i < devtype->nr_uart; i++)
- if (test_and_clear_bit(s->p[i].port.line, &sc16is7xx_lines))
+ if (test_and_clear_bit(s->p[i].port.line, sc16is7xx_lines))
uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
kthread_stop(s->kworker_task);
@@ -1669,7 +1670,7 @@ static void sc16is7xx_remove(struct device *dev)
for (i = 0; i < s->devtype->nr_uart; i++) {
kthread_cancel_delayed_work_sync(&s->p[i].ms_work);
- if (test_and_clear_bit(s->p[i].port.line, &sc16is7xx_lines))
+ if (test_and_clear_bit(s->p[i].port.line, sc16is7xx_lines))
uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
sc16is7xx_power(&s->p[i].port, 0);
}
@@ -1726,7 +1727,7 @@ static unsigned int sc16is7xx_regmap_port_mask(unsigned int port_id)
static int sc16is7xx_spi_probe(struct spi_device *spi)
{
const struct sc16is7xx_devtype *devtype;
- struct regmap *regmaps[2];
+ struct regmap *regmaps[SC16IS7XX_MAX_PORTS];
unsigned int i;
int ret;
@@ -1742,15 +1743,9 @@ static int sc16is7xx_spi_probe(struct spi_device *spi)
if (ret)
return ret;
- if (spi->dev.of_node) {
- devtype = device_get_match_data(&spi->dev);
- if (!devtype)
- return -ENODEV;
- } else {
- const struct spi_device_id *id_entry = spi_get_device_id(spi);
-
- devtype = (struct sc16is7xx_devtype *)id_entry->driver_data;
- }
+ devtype = spi_get_device_match_data(spi);
+ if (!devtype)
+ return dev_err_probe(&spi->dev, -ENODEV, "Failed to match device\n");
for (i = 0; i < devtype->nr_uart; i++) {
regcfg.name = sc16is7xx_regmap_name(i);
@@ -1795,25 +1790,18 @@ static struct spi_driver sc16is7xx_spi_uart_driver = {
.remove = sc16is7xx_spi_remove,
.id_table = sc16is7xx_spi_id_table,
};
-
-MODULE_ALIAS("spi:sc16is7xx");
#endif
#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
static int sc16is7xx_i2c_probe(struct i2c_client *i2c)
{
- const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
const struct sc16is7xx_devtype *devtype;
- struct regmap *regmaps[2];
+ struct regmap *regmaps[SC16IS7XX_MAX_PORTS];
unsigned int i;
- if (i2c->dev.of_node) {
- devtype = device_get_match_data(&i2c->dev);
- if (!devtype)
- return -ENODEV;
- } else {
- devtype = (struct sc16is7xx_devtype *)id->driver_data;
- }
+ devtype = i2c_get_match_data(i2c);
+ if (!devtype)
+ return dev_err_probe(&i2c->dev, -ENODEV, "Failed to match device\n");
for (i = 0; i < devtype->nr_uart; i++) {
regcfg.name = sc16is7xx_regmap_name(i);