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path: root/drivers/tty/serial/8250/8250_bcm7271.c
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Diffstat (limited to 'drivers/tty/serial/8250/8250_bcm7271.c')
-rw-r--r--drivers/tty/serial/8250/8250_bcm7271.c258
1 files changed, 128 insertions, 130 deletions
diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
index ed5a94747692..742004d63c6f 100644
--- a/drivers/tty/serial/8250/8250_bcm7271.c
+++ b/drivers/tty/serial/8250/8250_bcm7271.c
@@ -22,6 +22,7 @@
#include <linux/delay.h>
#include <linux/clk.h>
#include <linux/debugfs.h>
+#include <linux/units.h>
#include "8250.h"
@@ -187,21 +188,19 @@
#define TX_BUF_SIZE 4096
#define RX_BUF_SIZE 4096
#define RX_BUFS_COUNT 2
-#define KHZ 1000
-#define MHZ(x) ((x) * KHZ * KHZ)
static const u32 brcmstb_rate_table[] = {
- MHZ(81),
- MHZ(108),
- MHZ(64), /* Actually 64285715 for some chips */
- MHZ(48),
+ 81 * HZ_PER_MHZ,
+ 108 * HZ_PER_MHZ,
+ 64 * HZ_PER_MHZ, /* Actually 64285715 for some chips */
+ 48 * HZ_PER_MHZ,
};
static const u32 brcmstb_rate_table_7278[] = {
- MHZ(81),
- MHZ(108),
+ 81 * HZ_PER_MHZ,
+ 108 * HZ_PER_MHZ,
0,
- MHZ(48),
+ 48 * HZ_PER_MHZ,
};
struct brcmuart_priv {
@@ -414,20 +413,18 @@ static int stop_tx_dma(struct uart_8250_port *p)
static int brcmuart_tx_dma(struct uart_8250_port *p)
{
struct brcmuart_priv *priv = p->port.private_data;
- struct circ_buf *xmit = &p->port.state->xmit;
+ struct tty_port *tport = &p->port.state->port;
u32 tx_size;
if (uart_tx_stopped(&p->port) || priv->tx_running ||
- uart_circ_empty(xmit)) {
+ kfifo_is_empty(&tport->xmit_fifo)) {
return 0;
}
- tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE);
priv->dma.tx_err = 0;
- memcpy(priv->tx_buf, &xmit->buf[xmit->tail], tx_size);
- uart_xmit_advance(&p->port, tx_size);
+ tx_size = uart_fifo_out(&p->port, priv->tx_buf, UART_XMIT_SIZE);
- if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
uart_write_wakeup(&p->port);
udma_writel(priv, REGS_DMA_TX, UDMA_TX_TRANSFER_LEN, tx_size);
@@ -541,7 +538,7 @@ static void brcmuart_tx_isr(struct uart_port *up, u32 isr)
struct brcmuart_priv *priv = up->private_data;
struct device *dev = up->dev;
struct uart_8250_port *port_8250 = up_to_u8250p(up);
- struct circ_buf *xmit = &port_8250->port.state->xmit;
+ struct tty_port *tport = &port_8250->port.state->port;
if (isr & UDMA_INTR_TX_ABORT) {
if (priv->tx_running)
@@ -549,7 +546,7 @@ static void brcmuart_tx_isr(struct uart_port *up, u32 isr)
return;
}
priv->tx_running = false;
- if (!uart_circ_empty(xmit) && !uart_tx_stopped(up))
+ if (!kfifo_is_empty(&tport->xmit_fifo) && !uart_tx_stopped(up))
brcmuart_tx_dma(port_8250);
}
@@ -567,7 +564,7 @@ static irqreturn_t brcmuart_isr(int irq, void *dev_id)
if (interrupts == 0)
return IRQ_NONE;
- spin_lock_irqsave(&up->lock, flags);
+ uart_port_lock_irqsave(up, &flags);
/* Clear all interrupts */
udma_writel(priv, REGS_DMA_ISR, UDMA_INTR_CLEAR, interrupts);
@@ -581,7 +578,7 @@ static irqreturn_t brcmuart_isr(int irq, void *dev_id)
if ((rval | tval) == 0)
dev_warn(dev, "Spurious interrupt: 0x%x\n", interrupts);
- spin_unlock_irqrestore(&up->lock, flags);
+ uart_port_unlock_irqrestore(up, flags);
return IRQ_HANDLED;
}
@@ -605,9 +602,13 @@ static int brcmuart_startup(struct uart_port *port)
/*
* Disable the Receive Data Interrupt because the DMA engine
* will handle this.
+ *
+ * Synchronize UART_IER access against the console.
*/
+ uart_port_lock_irq(port);
up->ier &= ~UART_IER_RDI;
serial_port_out(port, UART_IER, up->ier);
+ uart_port_unlock_irq(port);
priv->tx_running = false;
priv->dma.rx_dma = NULL;
@@ -625,7 +626,7 @@ static void brcmuart_shutdown(struct uart_port *port)
struct brcmuart_priv *priv = up->port.private_data;
unsigned long flags;
- spin_lock_irqsave(&port->lock, flags);
+ uart_port_lock_irqsave(port, &flags);
priv->shutdown = true;
if (priv->dma_enabled) {
stop_rx_dma(up);
@@ -641,7 +642,7 @@ static void brcmuart_shutdown(struct uart_port *port)
*/
up->dma = NULL;
- spin_unlock_irqrestore(&port->lock, flags);
+ uart_port_unlock_irqrestore(port, flags);
serial8250_do_shutdown(port);
}
@@ -672,18 +673,46 @@ static void init_real_clk_rates(struct device *dev, struct brcmuart_priv *priv)
clk_set_rate(priv->baud_mux_clk, priv->default_mux_rate);
}
+static u32 find_quot(struct device *dev, u32 freq, u32 baud, u32 *percent)
+{
+ u32 quot;
+ u32 rate;
+ u64 hires_rate;
+ u64 hires_baud;
+ u64 hires_err;
+
+ rate = freq / 16;
+ quot = DIV_ROUND_CLOSEST(rate, baud);
+ if (!quot)
+ return 0;
+
+ /* increase resolution to get xx.xx percent */
+ hires_rate = div_u64((u64)rate * 10000, (u64)quot);
+ hires_baud = (u64)baud * 10000;
+
+ /* get the delta */
+ if (hires_rate > hires_baud)
+ hires_err = (hires_rate - hires_baud);
+ else
+ hires_err = (hires_baud - hires_rate);
+
+ *percent = (unsigned long)DIV_ROUND_CLOSEST_ULL(hires_err, baud);
+
+ dev_dbg(dev, "Baud rate: %u, MUX Clk: %u, Error: %u.%u%%\n",
+ baud, freq, *percent / 100, *percent % 100);
+
+ return quot;
+}
+
static void set_clock_mux(struct uart_port *up, struct brcmuart_priv *priv,
u32 baud)
{
u32 percent;
u32 best_percent = UINT_MAX;
u32 quot;
+ u32 freq;
u32 best_quot = 1;
- u32 rate;
- int best_index = -1;
- u64 hires_rate;
- u64 hires_baud;
- u64 hires_err;
+ u32 best_freq = 0;
int rc;
int i;
int real_baud;
@@ -692,44 +721,35 @@ static void set_clock_mux(struct uart_port *up, struct brcmuart_priv *priv,
if (priv->baud_mux_clk == NULL)
return;
- /* Find the closest match for specified baud */
- for (i = 0; i < ARRAY_SIZE(priv->real_rates); i++) {
- if (priv->real_rates[i] == 0)
- continue;
- rate = priv->real_rates[i] / 16;
- quot = DIV_ROUND_CLOSEST(rate, baud);
- if (!quot)
- continue;
-
- /* increase resolution to get xx.xx percent */
- hires_rate = (u64)rate * 10000;
- hires_baud = (u64)baud * 10000;
-
- hires_err = div_u64(hires_rate, (u64)quot);
-
- /* get the delta */
- if (hires_err > hires_baud)
- hires_err = (hires_err - hires_baud);
- else
- hires_err = (hires_baud - hires_err);
-
- percent = (unsigned long)DIV_ROUND_CLOSEST_ULL(hires_err, baud);
- dev_dbg(up->dev,
- "Baud rate: %u, MUX Clk: %u, Error: %u.%u%%\n",
- baud, priv->real_rates[i], percent / 100,
- percent % 100);
- if (percent < best_percent) {
- best_percent = percent;
- best_index = i;
- best_quot = quot;
+ /* Try default_mux_rate first */
+ quot = find_quot(up->dev, priv->default_mux_rate, baud, &percent);
+ if (quot) {
+ best_percent = percent;
+ best_freq = priv->default_mux_rate;
+ best_quot = quot;
+ }
+ /* If more than 1% error, find the closest match for specified baud */
+ if (best_percent > 100) {
+ for (i = 0; i < ARRAY_SIZE(priv->real_rates); i++) {
+ freq = priv->real_rates[i];
+ if (freq == 0 || freq == priv->default_mux_rate)
+ continue;
+ quot = find_quot(up->dev, freq, baud, &percent);
+ if (!quot)
+ continue;
+
+ if (percent < best_percent) {
+ best_percent = percent;
+ best_freq = freq;
+ best_quot = quot;
+ }
}
}
- if (best_index == -1) {
+ if (!best_freq) {
dev_err(up->dev, "Error, %d BAUD rate is too fast.\n", baud);
return;
}
- rate = priv->real_rates[best_index];
- rc = clk_set_rate(priv->baud_mux_clk, rate);
+ rc = clk_set_rate(priv->baud_mux_clk, best_freq);
if (rc)
dev_err(up->dev, "Error selecting BAUD MUX clock\n");
@@ -738,8 +758,8 @@ static void set_clock_mux(struct uart_port *up, struct brcmuart_priv *priv,
dev_err(up->dev, "Error, baud: %d has %u.%u%% error\n",
baud, percent / 100, percent % 100);
- real_baud = rate / 16 / best_quot;
- dev_dbg(up->dev, "Selecting BAUD MUX rate: %u\n", rate);
+ real_baud = best_freq / 16 / best_quot;
+ dev_dbg(up->dev, "Selecting BAUD MUX rate: %u\n", best_freq);
dev_dbg(up->dev, "Requested baud: %u, Actual baud: %u\n",
baud, real_baud);
@@ -748,7 +768,7 @@ static void set_clock_mux(struct uart_port *up, struct brcmuart_priv *priv,
i += (i / 2);
priv->char_wait = ns_to_ktime(i);
- up->uartclk = rate;
+ up->uartclk = best_freq;
}
static void brcmstb_set_termios(struct uart_port *up,
@@ -784,7 +804,7 @@ static int brcmuart_handle_irq(struct uart_port *p)
* interrupt but there is no data ready.
*/
if (((iir & UART_IIR_ID) == UART_IIR_RX_TIMEOUT) && !(priv->shutdown)) {
- spin_lock_irqsave(&p->lock, flags);
+ uart_port_lock_irqsave(p, &flags);
status = serial_port_in(p, UART_LSR);
if ((status & UART_LSR_DR) == 0) {
@@ -792,7 +812,7 @@ static int brcmuart_handle_irq(struct uart_port *p)
/*
* if Receive Data Interrupt is enabled and
* we're uing hardware flow control, deassert
- * RTS and wait for any chars in the pipline to
+ * RTS and wait for any chars in the pipeline to
* arrive and then check for DR again.
*/
if ((ier & UART_IER_RDI) && (up->mcr & UART_MCR_AFE)) {
@@ -809,7 +829,7 @@ static int brcmuart_handle_irq(struct uart_port *p)
handled = 1;
}
- spin_unlock_irqrestore(&p->lock, flags);
+ uart_port_unlock_irqrestore(p, flags);
if (handled)
return 1;
}
@@ -827,7 +847,7 @@ static enum hrtimer_restart brcmuart_hrtimer_func(struct hrtimer *t)
if (priv->shutdown)
return HRTIMER_NORESTART;
- spin_lock_irqsave(&p->lock, flags);
+ uart_port_lock_irqsave(p, &flags);
status = serial_port_in(p, UART_LSR);
/*
@@ -851,7 +871,7 @@ static enum hrtimer_restart brcmuart_hrtimer_func(struct hrtimer *t)
status |= UART_MCR_RTS;
serial_port_out(p, UART_MCR, status);
}
- spin_unlock_irqrestore(&p->lock, flags);
+ uart_port_unlock_irqrestore(p, flags);
return HRTIMER_NORESTART;
}
@@ -932,17 +952,14 @@ static void brcmuart_init_debugfs(struct brcmuart_priv *priv,
static int brcmuart_probe(struct platform_device *pdev)
{
struct resource *regs;
- struct device_node *np = pdev->dev.of_node;
const struct of_device_id *of_id = NULL;
struct uart_8250_port *new_port;
struct device *dev = &pdev->dev;
struct brcmuart_priv *priv;
struct clk *baud_mux_clk;
struct uart_8250_port up;
- int irq;
void __iomem *membase = NULL;
resource_size_t mapbase = 0;
- u32 clk_rate = 0;
int ret;
int x;
int dma_irq;
@@ -950,15 +967,12 @@ static int brcmuart_probe(struct platform_device *pdev)
"uart", "dma_rx", "dma_tx", "dma_intr2", "dma_arb"
};
- irq = platform_get_irq(pdev, 0);
- if (irq < 0)
- return irq;
priv = devm_kzalloc(dev, sizeof(struct brcmuart_priv),
GFP_KERNEL);
if (!priv)
return -ENOMEM;
- of_id = of_match_node(brcmuart_dt_ids, np);
+ of_id = of_match_node(brcmuart_dt_ids, dev->of_node);
if (!of_id || !of_id->data)
priv->rate_table = brcmstb_rate_table;
else
@@ -980,10 +994,9 @@ static int brcmuart_probe(struct platform_device *pdev)
}
/* We should have just the uart base registers or all the registers */
- if (x != 1 && x != REGS_MAX) {
- dev_warn(dev, "%s registers not specified\n", reg_names[x]);
- return -EINVAL;
- }
+ if (x != 1 && x != REGS_MAX)
+ return dev_err_probe(dev, -EINVAL, "%s registers not specified\n",
+ reg_names[x]);
/* if the DMA registers were specified, try to enable DMA */
if (x > REGS_DMA_RX) {
@@ -1009,57 +1022,41 @@ static int brcmuart_probe(struct platform_device *pdev)
}
}
- of_property_read_u32(np, "clock-frequency", &clk_rate);
-
- /* See if a Baud clock has been specified */
- baud_mux_clk = of_clk_get_by_name(np, "sw_baud");
- if (IS_ERR(baud_mux_clk)) {
- if (PTR_ERR(baud_mux_clk) == -EPROBE_DEFER)
- return -EPROBE_DEFER;
- dev_dbg(dev, "BAUD MUX clock not specified\n");
- } else {
- dev_dbg(dev, "BAUD MUX clock found\n");
- ret = clk_prepare_enable(baud_mux_clk);
- if (ret)
- return ret;
- priv->baud_mux_clk = baud_mux_clk;
- init_real_clk_rates(dev, priv);
- clk_rate = priv->default_mux_rate;
- }
-
- if (clk_rate == 0) {
- dev_err(dev, "clock-frequency or clk not defined\n");
- return -EINVAL;
- }
-
dev_dbg(dev, "DMA is %senabled\n", priv->dma_enabled ? "" : "not ");
memset(&up, 0, sizeof(up));
- up.port.type = PORT_16550A;
- up.port.uartclk = clk_rate;
+ up.port.type = PORT_BCM7271;
up.port.dev = dev;
up.port.mapbase = mapbase;
up.port.membase = membase;
- up.port.irq = irq;
up.port.handle_irq = brcmuart_handle_irq;
- up.port.regshift = 2;
- up.port.iotype = of_device_is_big_endian(np) ?
- UPIO_MEM32BE : UPIO_MEM32;
- up.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF
- | UPF_FIXED_PORT | UPF_FIXED_TYPE;
- up.port.dev = dev;
+ up.port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_FIXED_TYPE;
up.port.private_data = priv;
- up.capabilities = UART_CAP_FIFO | UART_CAP_AFE;
- up.port.fifosize = 32;
- /* Check for a fixed line number */
- ret = of_alias_get_id(np, "serial");
- if (ret >= 0)
- up.port.line = ret;
+ ret = uart_read_port_properties(&up.port);
+ if (ret)
+ goto release_dma;
+
+ up.port.regshift = 2;
+ up.port.iotype = device_is_big_endian(dev) ? UPIO_MEM32BE : UPIO_MEM32;
+
+ /* See if a Baud clock has been specified */
+ baud_mux_clk = devm_clk_get_optional_enabled(dev, "sw_baud");
+ ret = PTR_ERR_OR_ZERO(baud_mux_clk);
+ if (ret)
+ goto release_dma;
+ if (baud_mux_clk) {
+ dev_dbg(dev, "BAUD MUX clock found\n");
+
+ priv->baud_mux_clk = baud_mux_clk;
+ init_real_clk_rates(dev, priv);
+ up.port.uartclk = priv->default_mux_rate;
+ } else {
+ dev_dbg(dev, "BAUD MUX clock not specified\n");
+ }
/* setup HR timer */
- hrtimer_init(&priv->hrt, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
- priv->hrt.function = brcmuart_hrtimer_func;
+ hrtimer_setup(&priv->hrt, brcmuart_hrtimer_func, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
up.port.shutdown = brcmuart_shutdown;
up.port.startup = brcmuart_startup;
@@ -1088,7 +1085,7 @@ static int brcmuart_probe(struct platform_device *pdev)
ret = serial8250_register_8250_port(&up);
if (ret < 0) {
- dev_err(dev, "unable to register 8250 port\n");
+ dev_err_probe(dev, ret, "unable to register 8250 port\n");
goto err;
}
priv->line = ret;
@@ -1097,14 +1094,13 @@ static int brcmuart_probe(struct platform_device *pdev)
if (priv->dma_enabled) {
dma_irq = platform_get_irq_byname(pdev, "dma");
if (dma_irq < 0) {
- ret = dma_irq;
- dev_err(dev, "no IRQ resource info\n");
+ ret = dev_err_probe(dev, dma_irq, "no IRQ resource info\n");
goto err1;
}
ret = devm_request_irq(dev, dma_irq, brcmuart_isr,
IRQF_SHARED, "uart DMA irq", &new_port->port);
if (ret) {
- dev_err(dev, "unable to register IRQ handler\n");
+ dev_err_probe(dev, ret, "unable to register IRQ handler\n");
goto err1;
}
}
@@ -1116,11 +1112,13 @@ err1:
serial8250_unregister_port(priv->line);
err:
brcmuart_free_bufs(dev, priv);
- brcmuart_arbitration(priv, 0);
+release_dma:
+ if (priv->dma_enabled)
+ brcmuart_arbitration(priv, 0);
return ret;
}
-static int brcmuart_remove(struct platform_device *pdev)
+static void brcmuart_remove(struct platform_device *pdev)
{
struct brcmuart_priv *priv = platform_get_drvdata(pdev);
@@ -1128,8 +1126,8 @@ static int brcmuart_remove(struct platform_device *pdev)
hrtimer_cancel(&priv->hrt);
serial8250_unregister_port(priv->line);
brcmuart_free_bufs(&pdev->dev, priv);
- brcmuart_arbitration(priv, 0);
- return 0;
+ if (priv->dma_enabled)
+ brcmuart_arbitration(priv, 0);
}
static int __maybe_unused brcmuart_suspend(struct device *dev)
@@ -1143,10 +1141,10 @@ static int __maybe_unused brcmuart_suspend(struct device *dev)
* This will prevent resume from enabling RTS before the
* baud rate has been restored.
*/
- spin_lock_irqsave(&port->lock, flags);
+ uart_port_lock_irqsave(port, &flags);
priv->saved_mctrl = port->mctrl;
port->mctrl &= ~TIOCM_RTS;
- spin_unlock_irqrestore(&port->lock, flags);
+ uart_port_unlock_irqrestore(port, flags);
serial8250_suspend_port(priv->line);
clk_disable_unprepare(priv->baud_mux_clk);
@@ -1185,10 +1183,10 @@ static int __maybe_unused brcmuart_resume(struct device *dev)
if (priv->saved_mctrl & TIOCM_RTS) {
/* Restore RTS */
- spin_lock_irqsave(&port->lock, flags);
+ uart_port_lock_irqsave(port, &flags);
port->mctrl |= TIOCM_RTS;
port->ops->set_mctrl(port, port->mctrl);
- spin_unlock_irqrestore(&port->lock, flags);
+ uart_port_unlock_irqrestore(port, flags);
}
return 0;