diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_bcm7271.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_bcm7271.c | 258 |
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; |
