From 904326ecac022ebaeb39cdfb206fd3b6551cdfca Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Thu, 16 Oct 2014 16:54:21 -0400 Subject: tty,serial: Unify UPF_* and ASYNC_* flag definitions The userspace-defined ASYNC_* flags in include/uapi/linux/tty_flags.h are the authoritative bit definitions for the serial_struct flags, and thus for any derivative values or fields. Although the serial core provides the TIOCSSERIAL and TIOCGSERIAL ioctls to set and retrieve these flags from userspace, it defines these bits independently, as UPF_* macros. Define the UPF_* macros which are userspace-modifiable directly from the ASYNC_* symbolic constants. Add compile-time test to ensure the bits changeable by TIOCSSERIAL match the defined range in the uapi header. Add ASYNCB_MAGIC_MULTIPLIER to the uapi header since this bit is programmable by userspace. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/tty_flags.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/tty_flags.h b/include/uapi/linux/tty_flags.h index eefcb483a2c0..7b516f7ee7e6 100644 --- a/include/uapi/linux/tty_flags.h +++ b/include/uapi/linux/tty_flags.h @@ -6,6 +6,8 @@ * shared by the tty_port flags structures. * * Define ASYNCB_* for convenient use with {test,set,clear}_bit. + * + * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable */ #define ASYNCB_HUP_NOTIFY 0 /* Notify getty on hangups and closes * on the callout port */ @@ -26,7 +28,8 @@ #define ASYNCB_BUGGY_UART 14 /* This is a buggy UART, skip some safety * checks. Note: can be dangerous! */ #define ASYNCB_AUTOPROBE 15 /* Port was autoprobed by PCI or PNP code */ -#define ASYNCB_LAST_USER 15 +#define ASYNCB_MAGIC_MULTIPLIER 16 /* Use special CLK or divisor */ +#define ASYNCB_LAST_USER 16 /* Internal flags used only by kernel */ #define ASYNCB_INITIALIZED 31 /* Serial port was initialized */ @@ -57,6 +60,7 @@ #define ASYNC_LOW_LATENCY (1U << ASYNCB_LOW_LATENCY) #define ASYNC_BUGGY_UART (1U << ASYNCB_BUGGY_UART) #define ASYNC_AUTOPROBE (1U << ASYNCB_AUTOPROBE) +#define ASYNC_MAGIC_MULTIPLIER (1U << ASYNCB_MAGIC_MULTIPLIER) #define ASYNC_FLAGS ((1U << (ASYNCB_LAST_USER + 1)) - 1) #define ASYNC_USR_MASK (ASYNC_SPD_MASK|ASYNC_CALLOUT_NOHUP| \ -- cgit v1.2.3-71-gd317 From 352f86187e1d3e9e27d3be237103dc83a48f882c Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Thu, 16 Oct 2014 16:54:22 -0400 Subject: tty: Document defunct ASYNC_* bits in uapi header Note the serial_struct flags for which the kernel ignores and performs no action. The flags cannot be removed since they form part of the userspace interface via the TIOCSSERIAL/TIOCGSERIAL ioctls. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/tty_flags.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/tty_flags.h b/include/uapi/linux/tty_flags.h index 7b516f7ee7e6..4e021e31c219 100644 --- a/include/uapi/linux/tty_flags.h +++ b/include/uapi/linux/tty_flags.h @@ -8,6 +8,7 @@ * Define ASYNCB_* for convenient use with {test,set,clear}_bit. * * Bits [0..ASYNCB_LAST_USER] are userspace defined/visible/changeable + * [x] in the bit comments indicates the flag is defunct and no longer used. */ #define ASYNCB_HUP_NOTIFY 0 /* Notify getty on hangups and closes * on the callout port */ @@ -19,15 +20,15 @@ #define ASYNCB_SKIP_TEST 6 /* Skip UART test during autoconfiguration */ #define ASYNCB_AUTO_IRQ 7 /* Do automatic IRQ during * autoconfiguration */ -#define ASYNCB_SESSION_LOCKOUT 8 /* Lock out cua opens based on session */ -#define ASYNCB_PGRP_LOCKOUT 9 /* Lock out cua opens based on pgrp */ -#define ASYNCB_CALLOUT_NOHUP 10 /* Don't do hangups for cua device */ +#define ASYNCB_SESSION_LOCKOUT 8 /* [x] Lock out cua opens based on session */ +#define ASYNCB_PGRP_LOCKOUT 9 /* [x] Lock out cua opens based on pgrp */ +#define ASYNCB_CALLOUT_NOHUP 10 /* [x] Don't do hangups for cua device */ #define ASYNCB_HARDPPS_CD 11 /* Call hardpps when CD goes high */ #define ASYNCB_SPD_SHI 12 /* Use 230400 instead of 38400 bps */ #define ASYNCB_LOW_LATENCY 13 /* Request low latency behaviour */ #define ASYNCB_BUGGY_UART 14 /* This is a buggy UART, skip some safety * checks. Note: can be dangerous! */ -#define ASYNCB_AUTOPROBE 15 /* Port was autoprobed by PCI or PNP code */ +#define ASYNCB_AUTOPROBE 15 /* [x] Port was autoprobed by PCI/PNP code */ #define ASYNCB_MAGIC_MULTIPLIER 16 /* Use special CLK or divisor */ #define ASYNCB_LAST_USER 16 -- cgit v1.2.3-71-gd317 From 31a171328e870c9f65d01191e51a75cde5f78ffd Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Mon, 29 Sep 2014 20:06:43 +0200 Subject: tty: serial: 8250_omap: add custom DMA-TX callback This patch provides mostly a copy of serial8250_tx_dma() + __dma_tx_complete() with the following extensions: - DMA bug At least on AM335x the following problem exists: Even if the TX FIFO is empty and a TX transfer is programmed (and started) the UART does not trigger the DMA transfer. After $TRESHOLD number of bytes have been written to the FIFO manually the UART reevaluates the whole situation and decides that now there is enough room in the FIFO and so the transfer begins. This problem has not been seen on DRA7 or beagle board xm (OMAP3). I am not sure if this is UART-IP core specific or DMA engine. The workaround is to use a threshold of one byte, program the DMA transfer minus one byte and then to put the first byte into the FIFO to kick start the transfer. - support for runtime PM RPM is enabled on start_tx(). We can't disable RPM on DMA complete callback because there is still data in the FIFO which is being sent. We have to wait until the FIFO is empty before we disable it. For this to happen we fake a TX sent error and enable THRI. Once the FIFO is empty we receive an interrupt and since the TTY-buffer is still empty we "put RPM" via __stop_tx(). Should it been filed then in the start_tx() path we should program the DMA transfer and remove the error flag and the THRI bit. Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_omap.c | 144 ++++++++++++++++++++++++++++++++++++ include/uapi/linux/serial_reg.h | 1 + 2 files changed, 145 insertions(+) (limited to 'include/uapi/linux') diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c index 2f653c48639d..5f183d197dfa 100644 --- a/drivers/tty/serial/8250/8250_omap.c +++ b/drivers/tty/serial/8250/8250_omap.c @@ -22,6 +22,7 @@ #include #include #include +#include #include "8250.h" @@ -29,6 +30,7 @@ #define UART_ERRATA_i202_MDR1_ACCESS (1 << 0) #define OMAP_UART_WER_HAS_TX_WAKEUP (1 << 1) +#define OMAP_DMA_TX_KICK (1 << 2) #define OMAP_UART_FCR_RX_TRIG 6 #define OMAP_UART_FCR_TX_TRIG 4 @@ -616,6 +618,148 @@ static void omap_8250_unthrottle(struct uart_port *port) pm_runtime_put_autosuspend(port->dev); } +#ifdef CONFIG_SERIAL_8250_DMA +static int omap_8250_tx_dma(struct uart_8250_port *p); + +static void omap_8250_dma_tx_complete(void *param) +{ + struct uart_8250_port *p = param; + struct uart_8250_dma *dma = p->dma; + struct circ_buf *xmit = &p->port.state->xmit; + unsigned long flags; + bool en_thri = false; + + dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr, + UART_XMIT_SIZE, DMA_TO_DEVICE); + + spin_lock_irqsave(&p->port.lock, flags); + + dma->tx_running = 0; + + xmit->tail += dma->tx_size; + xmit->tail &= UART_XMIT_SIZE - 1; + p->port.icount.tx += dma->tx_size; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&p->port); + + if (!uart_circ_empty(xmit) && !uart_tx_stopped(&p->port)) { + int ret; + + ret = omap_8250_tx_dma(p); + if (ret) + en_thri = true; + + } else if (p->capabilities & UART_CAP_RPM) { + en_thri = true; + } + + if (en_thri) { + dma->tx_err = 1; + p->ier |= UART_IER_THRI; + serial_port_out(&p->port, UART_IER, p->ier); + } + + spin_unlock_irqrestore(&p->port.lock, flags); +} + +static int omap_8250_tx_dma(struct uart_8250_port *p) +{ + struct uart_8250_dma *dma = p->dma; + struct omap8250_priv *priv = p->port.private_data; + struct circ_buf *xmit = &p->port.state->xmit; + struct dma_async_tx_descriptor *desc; + unsigned int skip_byte = 0; + int ret; + + if (dma->tx_running) + return 0; + if (uart_tx_stopped(&p->port) || uart_circ_empty(xmit)) { + + /* + * Even if no data, we need to return an error for the two cases + * below so serial8250_tx_chars() is invoked and properly clears + * THRI and/or runtime suspend. + */ + if (dma->tx_err || p->capabilities & UART_CAP_RPM) { + ret = -EBUSY; + goto err; + } + if (p->ier & UART_IER_THRI) { + p->ier &= ~UART_IER_THRI; + serial_out(p, UART_IER, p->ier); + } + return 0; + } + + dma->tx_size = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); + if (priv->habit & OMAP_DMA_TX_KICK) { + u8 tx_lvl; + + /* + * We need to put the first byte into the FIFO in order to start + * the DMA transfer. For transfers smaller than four bytes we + * don't bother doing DMA at all. It seem not matter if there + * are still bytes in the FIFO from the last transfer (in case + * we got here directly from omap_8250_dma_tx_complete()). Bytes + * leaving the FIFO seem not to trigger the DMA transfer. It is + * really the byte that we put into the FIFO. + * If the FIFO is already full then we most likely got here from + * omap_8250_dma_tx_complete(). And this means the DMA engine + * just completed its work. We don't have to wait the complete + * 86us at 115200,8n1 but around 60us (not to mention lower + * baudrates). So in that case we take the interrupt and try + * again with an empty FIFO. + */ + tx_lvl = serial_in(p, UART_OMAP_TX_LVL); + if (tx_lvl == p->tx_loadsz) { + ret = -EBUSY; + goto err; + } + if (dma->tx_size < 4) { + ret = -EINVAL; + goto err; + } + skip_byte = 1; + } + + desc = dmaengine_prep_slave_single(dma->txchan, + dma->tx_addr + xmit->tail + skip_byte, + dma->tx_size - skip_byte, DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + ret = -EBUSY; + goto err; + } + + dma->tx_running = 1; + + desc->callback = omap_8250_dma_tx_complete; + desc->callback_param = p; + + dma->tx_cookie = dmaengine_submit(desc); + + dma_sync_single_for_device(dma->txchan->device->dev, dma->tx_addr, + UART_XMIT_SIZE, DMA_TO_DEVICE); + + dma_async_issue_pending(dma->txchan); + if (dma->tx_err) + dma->tx_err = 0; + + if (p->ier & UART_IER_THRI) { + p->ier &= ~UART_IER_THRI; + serial_out(p, UART_IER, p->ier); + } + if (skip_byte) + serial_out(p, UART_TX, xmit->buf[xmit->tail]); + return 0; +err: + dma->tx_err = 1; + return ret; +} + +#endif + static int omap8250_probe(struct platform_device *pdev) { struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); diff --git a/include/uapi/linux/serial_reg.h b/include/uapi/linux/serial_reg.h index df6c9ab6b0cd..53af3b790129 100644 --- a/include/uapi/linux/serial_reg.h +++ b/include/uapi/linux/serial_reg.h @@ -359,6 +359,7 @@ #define UART_OMAP_SYSC 0x15 /* System configuration register */ #define UART_OMAP_SYSS 0x16 /* System status register */ #define UART_OMAP_WER 0x17 /* Wake-up enable register */ +#define UART_OMAP_TX_LVL 0x1a /* TX FIFO level register */ /* * These are the definitions for the MDR1 register -- cgit v1.2.3-71-gd317 From 5ac9c05d789044d30735402f387355a394ec8e18 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Wed, 5 Nov 2014 12:26:30 -0500 Subject: tty: Document defunct ASYNC_SPLIT_TERMIOS flag in uapi header The last vestige of ASYNC_SPLIT_TERMIOS was removed by commit 'cris: Remove obsolete ASYNC_SPLIT_TERMIOS behavior'. Mark the flag as defunct in the uapi header. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- include/uapi/linux/tty_flags.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/tty_flags.h b/include/uapi/linux/tty_flags.h index 4e021e31c219..d2bc4ff94f43 100644 --- a/include/uapi/linux/tty_flags.h +++ b/include/uapi/linux/tty_flags.h @@ -14,7 +14,7 @@ * on the callout port */ #define ASYNCB_FOURPORT 1 /* Set OU1, OUT2 per AST Fourport settings */ #define ASYNCB_SAK 2 /* Secure Attention Key (Orange book) */ -#define ASYNCB_SPLIT_TERMIOS 3 /* Separate termios for dialin/callout */ +#define ASYNCB_SPLIT_TERMIOS 3 /* [x] Separate termios for dialin/callout */ #define ASYNCB_SPD_HI 4 /* Use 56000 instead of 38400 bps */ #define ASYNCB_SPD_VHI 5 /* Use 115200 instead of 38400 bps */ #define ASYNCB_SKIP_TEST 6 /* Skip UART test during autoconfiguration */ -- cgit v1.2.3-71-gd317 From 68952076e9226cc23ebce66d3fc2fdb8b6c04c30 Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Wed, 5 Nov 2014 12:26:31 -0500 Subject: vt: Remove vt_get_kmsg_redirect() from uapi header vt_get_kmsg_redirect() only has meaning to the console driver as an alias for calling vt_kmsg_redirect(). Move the macro definition to the only source file which uses it; remove from uapi/linux/vt.h Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/vt.c | 2 ++ include/uapi/linux/vt.h | 3 --- 2 files changed, 2 insertions(+), 3 deletions(-) (limited to 'include/uapi/linux') diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index b33b00b386de..3dc5d56261a5 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -2509,6 +2509,8 @@ int vt_kmsg_redirect(int new) return kmsg_con; } +#define vt_get_kmsg_redirect() vt_kmsg_redirect(-1) + /* * Console on virtual terminal * diff --git a/include/uapi/linux/vt.h b/include/uapi/linux/vt.h index 4b59a26799a3..978578bd1895 100644 --- a/include/uapi/linux/vt.h +++ b/include/uapi/linux/vt.h @@ -84,7 +84,4 @@ struct vt_setactivate { #define VT_SETACTIVATE 0x560F /* Activate and set the mode of a console */ - -#define vt_get_kmsg_redirect() vt_kmsg_redirect(-1) - #endif /* _UAPI_LINUX_VT_H */ -- cgit v1.2.3-71-gd317 From 9b8777e3473e31b2aabd669e5f34866d4a3afb6a Mon Sep 17 00:00:00 2001 From: John Crispin Date: Thu, 16 Oct 2014 21:48:21 +0200 Subject: serial: of: add a PORT_RT2880 definition The Ralink RT2880 SoC and its successors have an internal 8250 core. This core needs the same quirks applied as the AMD AU1xxx uart. In addition to these quirks, the ports memory region is only 0x100 unlike the AU1xxx which has a size of 0x1000. Signed-off-by: John Crispin Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_core.c | 5 ++++- drivers/tty/serial/of_serial.c | 10 +++++++++- include/uapi/linux/serial_core.h | 3 ++- 3 files changed, 15 insertions(+), 3 deletions(-) (limited to 'include/uapi/linux') diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 7e78f3077b5d..223503299e99 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -2640,8 +2640,11 @@ serial8250_pm(struct uart_port *port, unsigned int state, static unsigned int serial8250_port_size(struct uart_8250_port *pt) { - if (pt->port.iotype == UPIO_AU) + if (pt->port.iotype == UPIO_AU) { + if (pt->port.type == PORT_RT2880) + return 0x100; return 0x1000; + } if (is_omap1_8250(pt)) return 0x16 << pt->port.regshift; diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c index 9c64ad2ac1a8..8749fb849803 100644 --- a/drivers/tty/serial/of_serial.c +++ b/drivers/tty/serial/of_serial.c @@ -130,8 +130,15 @@ static int of_platform_serial_setup(struct platform_device *ofdev, port->dev = &ofdev->dev; - if (type == PORT_TEGRA) + switch (type) { + case PORT_TEGRA: port->handle_break = tegra_serial_handle_break; + break; + + case PORT_RT2880: + port->iotype = UPIO_AU; + break; + } return 0; out: @@ -317,6 +324,7 @@ static struct of_device_id of_platform_serial_table[] = { { .compatible = "ns16850", .data = (void *)PORT_16850, }, { .compatible = "nvidia,tegra20-uart", .data = (void *)PORT_TEGRA, }, { .compatible = "nxp,lpc3220-uart", .data = (void *)PORT_LPC3220, }, + { .compatible = "ralink,rt2880-uart", .data = (void *)PORT_RT2880, }, { .compatible = "altr,16550-FIFO32", .data = (void *)PORT_ALTR_16550_F32, }, { .compatible = "altr,16550-FIFO64", diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h index 16ad8521af6a..c17218094f18 100644 --- a/include/uapi/linux/serial_core.h +++ b/include/uapi/linux/serial_core.h @@ -54,7 +54,8 @@ #define PORT_ALTR_16550_F32 26 /* Altera 16550 UART with 32 FIFOs */ #define PORT_ALTR_16550_F64 27 /* Altera 16550 UART with 64 FIFOs */ #define PORT_ALTR_16550_F128 28 /* Altera 16550 UART with 128 FIFOs */ -#define PORT_MAX_8250 28 /* max port ID */ +#define PORT_RT2880 29 /* Ralink RT2880 internal UART */ +#define PORT_MAX_8250 29 /* max port ID */ /* * ARM specific type numbers. These are not currently guaranteed -- cgit v1.2.3-71-gd317 From 8a8ae62f8296760a2a1eee7009a1444c327603e0 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Thu, 6 Nov 2014 16:56:33 +0100 Subject: tty: warn on deprecated serial flags When somebody calls TIOCSSERIAL ioctl with serial flags to set one of * ASYNC_SESSION_LOCKOUT * ASYNC_PGRP_LOCKOUT * ASYNC_CALLOUT_NOHUP * ASYNC_AUTOPROBE nothing happens. We actually ignore the flags for over a decade at least (I checked 2.6.0). So start yelling at users who use those flags, that they shouldn't. Signed-off-by: Jiri Slaby Cc: Peter Hurley Cc: Alan Cox Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_io.c | 21 +++++++++++++++++++++ include/uapi/linux/tty_flags.h | 2 ++ 2 files changed, 23 insertions(+) (limited to 'include/uapi/linux') diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 01d45fd7d359..705885891b87 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -2760,6 +2760,24 @@ static int tty_tiocgicount(struct tty_struct *tty, void __user *arg) return 0; } +static void tty_warn_deprecated_flags(struct serial_struct __user *ss) +{ + static DEFINE_RATELIMIT_STATE(depr_flags, + DEFAULT_RATELIMIT_INTERVAL, + DEFAULT_RATELIMIT_BURST); + char comm[TASK_COMM_LEN]; + int flags; + + if (get_user(flags, &ss->flags)) + return; + + flags &= ASYNC_DEPRECATED; + + if (flags && __ratelimit(&depr_flags)) + pr_warning("%s: '%s' is using deprecated serial flags (with no effect): %.8x\n", + __func__, get_task_comm(comm, current), flags); +} + /* * if pty, return the slave side (real_tty) * otherwise, return self @@ -2903,6 +2921,9 @@ long tty_ioctl(struct file *file, unsigned int cmd, unsigned long arg) break; } break; + case TIOCSSERIAL: + tty_warn_deprecated_flags(p); + break; } if (tty->ops->ioctl) { retval = tty->ops->ioctl(tty, cmd, arg); diff --git a/include/uapi/linux/tty_flags.h b/include/uapi/linux/tty_flags.h index d2bc4ff94f43..fae4864737fa 100644 --- a/include/uapi/linux/tty_flags.h +++ b/include/uapi/linux/tty_flags.h @@ -64,6 +64,8 @@ #define ASYNC_MAGIC_MULTIPLIER (1U << ASYNCB_MAGIC_MULTIPLIER) #define ASYNC_FLAGS ((1U << (ASYNCB_LAST_USER + 1)) - 1) +#define ASYNC_DEPRECATED (ASYNC_SESSION_LOCKOUT | ASYNC_PGRP_LOCKOUT | \ + ASYNC_CALLOUT_NOHUP | ASYNC_AUTOPROBE) #define ASYNC_USR_MASK (ASYNC_SPD_MASK|ASYNC_CALLOUT_NOHUP| \ ASYNC_LOW_LATENCY) #define ASYNC_SPD_CUST (ASYNC_SPD_HI|ASYNC_SPD_VHI) -- cgit v1.2.3-71-gd317