[alsa-devel] Serial MIDI driver for PL011 - as found on BCM2835 hardware
Takashi Iwai
tiwai at suse.de
Fri Nov 7 11:05:22 CET 2014
At Fri, 07 Nov 2014 11:40:38 +1100,
Kim Taylor wrote:
>
> Here's the patch. In line with Takashi's comment, I've not split the
> modules. There is not much to be shared.
I see differently: there are many shared codes. For example, the
adaptor-specific codes should be shared. There is no reason to have
doubly "MS-124T" or whatever-specific things in two places.
> Recent changes include using a
> hrtimer instead of a timer for half duplex mode.
The hrtimer code isn't again specific to R-Pi, right? It'd be better
to enhance this generically in the serial MIDI driver.
What are the other differences? Suppose you replace the hw register
accessors in an abstract form, i.e. instead of outb() or writeb(),
calling a driver callback, ops->write_byte(). How many codes can be
shared by two devices?
thanks,
Takashi
> I've been using the driver for a couple of weeks now and it appears to
> be stable.
>
> diff -uprN sound-orig/sound/drivers/Kconfig
> sound-new/sound/drivers/Kconfig
> --- sound-orig/sound/drivers/Kconfig 2014-11-07 11:24:19.000000000 +1100
> +++ sound-new/sound/drivers/Kconfig 2014-11-07 11:19:21.000000000 +1100
> @@ -148,6 +148,22 @@ config SND_SERIAL_U16550
> To compile this driver as a module, choose M here: the module
> will be called snd-serial-u16550.
>
> +config SND_SERIAL_PL011
> + tristate "PL011 serial MIDI driver"
> + select SND_RAWMIDI
> + help
> + To include support for MIDI serial port interfaces, say Y here
> + and read <file:Documentation/sound/alsa/serial-u16550.txt>.
> + This driver works with serial PL011 uarts, as found on the
> + Raspberry pi.
> +
> + This driver accesses the serial port hardware directly, so
> + make sure that the standard serial driver isn't used or
> + deactivated with setserial before loading this driver.
> +
> + To compile this driver as a module, choose M here: the module
> + will be called snd-serial-pl011.
> +
> config SND_MPU401
> tristate "Generic MPU-401 UART driver"
> select SND_MPU401_UART
> diff -uprN sound-orig/sound/drivers/Makefile
> sound-new/sound/drivers/Makefile
> --- sound-orig/sound/drivers/Makefile 2014-11-07 11:24:19.000000000
> +1100
> +++ sound-new/sound/drivers/Makefile 2014-11-07 11:16:49.000000000 +1100
> @@ -9,6 +9,7 @@ snd-mtpav-objs := mtpav.o
> snd-mts64-objs := mts64.o
> snd-portman2x4-objs := portman2x4.o
> snd-serial-u16550-objs := serial-u16550.o
> +snd-serial-pl011-objs := serial-pl011.o
> snd-virmidi-objs := virmidi.o
> snd-ml403-ac97cr-objs := ml403-ac97cr.o pcm-indirect2.o
>
> @@ -17,6 +18,7 @@ obj-$(CONFIG_SND_DUMMY) += snd-dummy.o
> obj-$(CONFIG_SND_ALOOP) += snd-aloop.o
> obj-$(CONFIG_SND_VIRMIDI) += snd-virmidi.o
> obj-$(CONFIG_SND_SERIAL_U16550) += snd-serial-u16550.o
> +obj-$(CONFIG_SND_SERIAL_PL011) += snd-serial-pl011.o
> obj-$(CONFIG_SND_MTPAV) += snd-mtpav.o
> obj-$(CONFIG_SND_MTS64) += snd-mts64.o
> obj-$(CONFIG_SND_PORTMAN2X4) += snd-portman2x4.o
> diff -uprN sound-orig/sound/drivers/serial-pl011.c
> sound-new/sound/drivers/serial-pl011.c
> --- sound-orig/sound/drivers/serial-pl011.c 1970-01-01
> 10:00:00.000000000 +1000
> +++ sound-new/sound/drivers/serial-pl011.c 2014-11-07 11:32:04.000000000
> +1100
> @@ -0,0 +1,1089 @@
> +/*
> + * serial-pl011.c
> + * Copyright (c) by Jaroslav Kysela <perex at perex.cz>,
> + * Isaku Yamahata <yamahata at private.email.ne.jp>,
> + * George Hansper <ghansper at apana.org.au>,
> + * Hannu Savolainen
> + * Kim Taylor
> + *
> + * This code is based on the code from serial-u16550.
> + *
> + * This program is free software; you can redistribute it and/or
> modify
> + * it under the terms of the GNU General Public License as published
> by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
> 02111-1307 USA
> + *
> + * Sat Mar 31 17:27:57 PST 2001 tim.mann at compaq.com
> + * Added support for the Midiator MS-124T and for the MS-124W in
> + * Single Addressed (S/A) or Multiple Burst (M/B) mode, with
> + * power derived either parasitically from the serial port or
> + * from a separate power supply.
> + *
> + * More documentation can be found in serial-u16550.txt.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/err.h>
> +#include <linux/slab.h>
> +#include <linux/ioport.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <sound/core.h>
> +#include <sound/rawmidi.h>
> +#include <sound/initval.h>
> +
> +#include <linux/amba/bus.h>
> +#include <linux/amba/serial.h>
> +#include <linux/pinctrl/consumer.h>
> +#include <linux/clk.h>
> +#include <linux/jiffies.h>
> +
> +#include <asm/io.h>
> +
> +MODULE_DESCRIPTION("MIDI serial pl011");
> +MODULE_LICENSE("GPL");
> +MODULE_SUPPORTED_DEVICE("{{ALSA, MIDI serial pl011}}");
> +
> +#define SNDRV_SERIAL_SOUNDCANVAS 0 /* Roland Soundcanvas; F5 NN selects
> part */
> +#define SNDRV_SERIAL_MS124T 1 /* Midiator MS-124T */
> +#define SNDRV_SERIAL_MS124W_SA 2 /* Midiator MS-124W in S/A mode */
> +#define SNDRV_SERIAL_MS124W_MB 3 /* Midiator MS-124W in M/B mode */
> +#define SNDRV_SERIAL_GENERIC 4 /* Generic Interface */
> +#define SNDRV_SERIAL_MAX_ADAPTOR SNDRV_SERIAL_GENERIC
> +static char *adaptor_names[] = {
> + "Soundcanvas",
> + "MS-124T",
> + "MS-124W S/A",
> + "MS-124W M/B",
> + "Generic"
> +};
> +
> +#define SNDRV_SERIAL_NORMALBUFF 0 /* Normal blocking buffer operation
> */
> +#define SNDRV_SERIAL_DROPBUFF 1 /* Non-blocking discard operation */
> +#define SNDRV_SERIAL_NOTHROTTLE 0
> +#define SNDRV_SERIAL_NORTSCTS 0
> +#define SNDRV_SERIAL_DEFAULT_FIFO 16
> +#define TIMER_ATTEMPTS_LIMIT 255
> +
> +static int speed = 115200; /* 9600,19200,38400,57600,115200 */
> +static int outs = 1; /* 1 to 16 */
> +static int ins = 1; /* 1 to 16 */
> +static int adaptor = SNDRV_SERIAL_GENERIC;
> +static bool droponfull = SNDRV_SERIAL_NORMALBUFF;
> +static bool throttle_tx = SNDRV_SERIAL_NOTHROTTLE;
> +static int throttle_delay = 1000;
> +static int fifo_limit = SNDRV_SERIAL_DEFAULT_FIFO;
> +static bool flow_control = SNDRV_SERIAL_NORTSCTS;
> +
> +module_param(speed, int, 0444);
> +MODULE_PARM_DESC(speed, "Speed in bauds.");
> +module_param(outs, int, 0444);
> +MODULE_PARM_DESC(outs, "Number of MIDI outputs.");
> +module_param(ins, int, 0444);
> +MODULE_PARM_DESC(ins, "Number of MIDI inputs.");
> +module_param(droponfull, bool, 0444);
> +MODULE_PARM_DESC(droponfull, "Flag to enable drop-on-full buffer
> mode");
> +module_param(throttle_tx, bool, 0444);
> +MODULE_PARM_DESC(throttle_tx, "Do not continuously fill TX FIFO");
> +module_param(throttle_delay, int, 0444);
> +MODULE_PARM_DESC(throttle_delay, "Time in us between each TX write");
> +module_param(flow_control, bool, 0444);
> +MODULE_PARM_DESC(flow_control, "Use RTS/CTS flow control");
> +module_param(fifo_limit, int, 0444);
> +MODULE_PARM_DESC(fifo_limit, "Maximum TX bytes per write");
> +
> +module_param(adaptor, int, 0444);
> +MODULE_PARM_DESC(adaptor, "Type of adaptor.");
> +
> +/*#define SNDRV_SERIAL_MS124W_MB_NOCOMBO 1*/ /* Address outs as 0-3
> instead of bitmap */
> +
> +#define SNDRV_SERIAL_MAX_OUTS 16 /* max 64, min 16 */
> +#define SNDRV_SERIAL_MAX_INS 16 /* max 64, min 16 */
> +
> +#define TX_BUFF_SIZE (1<<15) /* Must be 2^n */
> +#define TX_BUFF_MASK (TX_BUFF_SIZE - 1)
> +
> +#define AMBA_ISR_PASS_LIMIT 256
> +
> +#define SERIAL_MODE_NOT_OPENED (0)
> +#define SERIAL_MODE_INPUT_OPEN (1 << 0)
> +#define SERIAL_MODE_OUTPUT_OPEN (1 << 1)
> +#define SERIAL_MODE_INPUT_TRIGGERED (1 << 2)
> +#define SERIAL_MODE_OUTPUT_TRIGGERED (1 << 3)
> +
> +struct snd_uart_pl011 {
> + struct amba_device *dev;
> + struct snd_card *card;
> + struct snd_rawmidi *rmidi;
> + struct snd_rawmidi_substream *midi_output[SNDRV_SERIAL_MAX_OUTS];
> + struct snd_rawmidi_substream *midi_input[SNDRV_SERIAL_MAX_INS];
> +
> + int filemode; /* open status of file */
> +
> + spinlock_t open_lock;
> + wait_queue_head_t drain_wait;
> + int draining;
> +
> + int irq;
> +
> + void __iomem *membase;
> + unsigned long mapbase;
> + struct resource *res_base;
> +
> + struct clk *clk;
> + unsigned long clk_rate;
> + unsigned int speed;
> +
> + /* parameter for using of write loop */
> + short int fifo_limit;
> + short int fifo_count;
> +
> + /* type of adaptor */
> + int adaptor;
> +
> + /* inputs */
> + int prev_in;
> + unsigned char rstatus;
> +
> + /* outputs */
> + int prev_out;
> + unsigned char prev_status[SNDRV_SERIAL_MAX_OUTS];
> +
> + /* write buffer and its writing/reading position */
> + unsigned char tx_buff[TX_BUFF_SIZE];
> + int buff_in_count;
> + int buff_in;
> + int buff_out;
> + int drop_on_full;
> + int throttle_tx;
> + int flow_control;
> + ktime_t throttle_delay;
> +
> + int timer_running;
> + u16 control_reg;
> + enum {
> + TX_IDLE,
> + TX_BLOCK_RX,
> + TX_BUSY,
> + } tx_state;
> + int tx_attempts;
> + struct hrtimer buffer_timer;
> +};
> +
> +static inline void snd_uart_pl011_stop_rx(struct snd_uart_pl011 *uart)
> +{
> + writew(uart->control_reg & ~UART011_CR_RTS, uart->membase +
> UART011_CR);
> +}
> +
> +static inline void snd_uart_pl011_start_rx(struct snd_uart_pl011 *uart)
> +{
> + writew(uart->control_reg | UART011_CR_RTS, uart->membase +
> UART011_CR);
> +}
> +
> +/* This macro is only used in snd_uart_pl011_io_loop */
> +static inline void snd_uart_pl011_buffer_output(struct snd_uart_pl011
> *uart)
> +{
> + unsigned short buff_out = uart->buff_out;
> + if (uart->buff_in_count > 0) {
> + writeb(uart->tx_buff[buff_out], uart->membase + UART01x_DR);
> + uart->fifo_count++;
> + buff_out++;
> + buff_out &= TX_BUFF_MASK;
> + uart->buff_out = buff_out;
> + uart->buff_in_count--;
> + }
> +}
> +
> +static inline int snd_uart_pl011_write_fifo_timer(struct snd_uart_pl011
> * uart)
> +{
> + /* Check CTS - FIFO is empty */
> + if (!uart->flow_control ||
> + readw(uart->membase + UART01x_FR) & UART01x_FR_CTS) {
> + while (uart->fifo_count < uart->fifo_limit
> + && uart->buff_in_count > 0)
> + snd_uart_pl011_buffer_output(uart);
> +
> + uart->tx_state = TX_BUSY;
> + if (unlikely(uart->draining))
> + wake_up(&uart->drain_wait);
> + return 1;
> + }
> + return 0;
> +}
> +
> +static inline void snd_uart_pl011_start_timer(struct snd_uart_pl011
> *uart)
> +{
> + if (!uart->timer_running) {
> + if (uart->flow_control) {
> + snd_uart_pl011_stop_rx(uart);
> + uart->tx_state = TX_BLOCK_RX;
> + uart->tx_attempts = TIMER_ATTEMPTS_LIMIT;
> + } else {
> + snd_uart_pl011_write_fifo_timer(uart);
> + }
> + hrtimer_start(&uart->buffer_timer, uart->throttle_delay,
> + HRTIMER_MODE_REL);
> + uart->timer_running = 1;
> + }
> +}
> +
> +static inline void snd_uart_pl011_del_timer(struct snd_uart_pl011
> *uart)
> +{
> + hrtimer_cancel(&uart->buffer_timer);
> + uart->timer_running = 0;
> +}
> +
> +/* This loop should be called with interrupts disabled
> + * We don't want to interrupt this,
> + * as we're already handling an interrupt
> + *
> + * PL011 interrupts that must be serviced (and cleared):
> + * UART011_RXIC (RX FIFO becoming full)
> + * UART011_TXIC (TX FIFO becoming empty)
> + * UART011_RTIC (RX timeout reached)
> + */
> +static void snd_uart_pl011_io_loop(struct snd_uart_pl011 * uart)
> +{
> + unsigned char c;
> + int substream;
> + int pass_counter = AMBA_ISR_PASS_LIMIT;
> +
> + /* recall previous stream */
> + substream = uart->prev_in;
> +
> + /* Read Loop */
> + while (!(readw(uart->membase + UART01x_FR) & UART01x_FR_RXFE)) {
> + /* while receive data ready */
> + c = readb(uart->membase + UART01x_DR);
> +
> + /* keep track of last status byte */
> + if (c & 0x80)
> + uart->rstatus = c;
> +
> + /* handle stream switch */
> + if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
> + if (uart->rstatus == 0xf5) {
> + if (c <= SNDRV_SERIAL_MAX_INS && c > 0)
> + substream = c - 1;
> + if (c != 0xf5)
> + /* prevent future bytes from being
> + interpreted as streams */
> + uart->rstatus = 0;
> + } else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN)
> + && uart->midi_input[substream])
> + snd_rawmidi_receive(uart->midi_input[substream],
> + &c, 1);
> + } else if ((uart->filemode & SERIAL_MODE_INPUT_OPEN) &&
> + uart->midi_input[substream])
> + snd_rawmidi_receive(uart->midi_input[substream], &c, 1);
> +
> + if (readw(uart->membase + UART01x_FR) & UART011_FR_RXFF)
> + snd_printk(KERN_WARNING
> + "%s: Overrun on device at 0x%lx\n",
> + uart->rmidi->name, uart->mapbase);
> +
> + if (pass_counter-- == 0) break;
> + }
> +
> + /* remember the last stream */
> + uart->prev_in = substream;
> +
> + if (uart->throttle_tx) return;
> +
> + /* Check write status, if we get a TX fifo interrupt,
> + * it's possible that there are still 2 bytes of data
> + * in the FIFO */
> + if (readw(uart->membase + UART011_MIS) & UART011_TXIS) {
> + writew(UART011_TXIC, uart->membase + UART011_ICR);
> + uart->fifo_count = 2;
> + if (unlikely(uart->draining)) wake_up(&uart->drain_wait);
> + }
> +
> + if (readw(uart->membase + UART01x_FR) & UART011_FR_TXFE)
> + uart->fifo_count = 0;
> +
> + /* Write loop */
> + while (uart->fifo_count < uart->fifo_limit /* Can we write ? */
> + && uart->buff_in_count > 0) /* Do we want to? */
> + snd_uart_pl011_buffer_output(uart);
> +}
> +
> +static irqreturn_t snd_uart_pl011_interrupt(int irq, void *dev_id)
> +{
> + struct snd_uart_pl011 *uart;
> +
> + uart = dev_id;
> + spin_lock(&uart->open_lock);
> + if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
> + spin_unlock(&uart->open_lock);
> + return IRQ_NONE;
> + }
> +
> + snd_uart_pl011_io_loop(uart);
> + spin_unlock(&uart->open_lock);
> + return IRQ_HANDLED;
> +}
> +
> +static enum hrtimer_restart snd_uart_pl011_buffer_timer(struct hrtimer
> *handle)
> +{
> + struct snd_uart_pl011 *uart =
> + container_of(handle, struct snd_uart_pl011, buffer_timer);
> + enum hrtimer_restart restart = HRTIMER_NORESTART;
> + int double_delay = 0;
> +
> + spin_lock(&uart->open_lock);
> +
> + switch (uart->tx_state) {
> + case TX_IDLE:
> + snd_uart_pl011_stop_rx(uart);
> + uart->tx_attempts = TIMER_ATTEMPTS_LIMIT;
> + uart->tx_state = TX_BLOCK_RX;
> + restart = HRTIMER_RESTART;
> + break;
> +
> + case TX_BLOCK_RX:
> + /* Write FIFO, reschedule if necessary */
> + if (snd_uart_pl011_write_fifo_timer(uart)) {
> + restart = HRTIMER_RESTART;
> + } else {
> + /* If the cable becomes disconnected, we may never get
> + * CTS. Therefore limit the number of times we call the
> + * timer */
> + if (uart->tx_attempts--) restart = HRTIMER_RESTART;
> + else uart->tx_state = TX_IDLE;
> + }
> +
> + break;
> +
> + case TX_BUSY:
> + if (readw(uart->membase + UART01x_FR) & UART01x_FR_BUSY) {
> + /* Still writing, reschedule */
> + restart = HRTIMER_RESTART;
> + } else {
> + /* Finished writing allow receive */
> + uart->fifo_count = 0;
> + if (uart->flow_control) {
> + double_delay = 1;
> + uart->tx_state = TX_IDLE;
> + snd_uart_pl011_start_rx(uart);
> + } else {
> + uart->tx_state = TX_BLOCK_RX;
> + }
> + if (uart->buff_in_count > 0) {
> + restart = HRTIMER_RESTART;
> + }
> + }
> + break;
> + }
> +
> + if (restart == HRTIMER_RESTART) {
> + hrtimer_forward_now(&uart->buffer_timer,
> + double_delay ? ktime_add(uart->throttle_delay,
> + uart->throttle_delay) : uart->throttle_delay);
> + } else
> + uart->timer_running = 0;
> +
> + spin_unlock(&uart->open_lock);
> +
> + return restart;
> +}
> +
> +static int snd_uart_pl011_detect(struct snd_uart_pl011 *uart)
> +{
> + int ok = 0;
> + u16 status;
> + int timeout = 1000;
> +
> + writew(0, uart->membase + UART011_IMSC); /* Disable interrupts */
> +
> + writew(UART01x_CR_UARTEN
> + | UART011_CR_TXE
> + | UART011_CR_LBE
> + | UART011_CR_RXE
> + , uart->membase + UART011_CR);
> +
> + writew(0, uart->membase + UART011_FBRD);
> + writew(1, uart->membase + UART011_IBRD);
> + writew(0, uart->membase + UART011_LCRH);
> + writew(0x55, uart->membase + UART01x_DR);
> + while (timeout &&
> + (readw(uart->membase + UART01x_FR) & UART01x_FR_BUSY)) {
> + timeout--;
> + barrier();
> + }
> + status = readw(uart->membase + UART01x_DR) & 0xff;
> + writew(0xffff, uart->membase + UART011_ICR); /* Clear interrupts */
> +
> + /* Loopback with WLEN == 5 turns 0x55 into 0x15 */
> + if (status == 0x15) ok = 1;
> +
> + return ok;
> +}
> +
> +static void snd_uart_pl011_do_open(struct snd_uart_pl011 * uart)
> +{
> + unsigned int quot;
> + u16 reg;
> +
> + /* Initialize basic variables */
> + uart->buff_in_count = 0;
> + uart->buff_in = 0;
> + uart->buff_out = 0;
> + uart->fifo_count = 0;
> + uart->tx_state = TX_IDLE;
> +
> + writew(UART01x_CR_UARTEN /* Enable UART */
> + | UART011_CR_TXE /* Enable UART TX */
> + | UART011_CR_RXE /* Enable UART RX */
> + , uart->membase + UART011_CR);
> +
> + uart->clk_rate = clk_get_rate(uart->clk);
> + quot = DIV_ROUND_CLOSEST(uart->clk_rate * 4, uart->speed);
> +
> + writew(quot & 0x3f, uart->membase + UART011_FBRD);
> + writew(quot >> 6, uart->membase + UART011_IBRD);
> +
> + writew(UART01x_LCRH_FEN /* Enable FIFOs */
> + | UART01x_LCRH_WLEN_8 /* 8 Bit words, 1 Stop, No Parity */
> + , uart->membase + UART011_LCRH); /* FIFO Control Register */
> +
> + writew(UART011_IFLS_RX2_8 /* Set RX FIFO trigger at 4-bytes */
> + | UART011_IFLS_TX1_8 /* Set TX FIFO trigger at 2-bytes */
> + , uart->membase + UART011_IFLS);
> +
> + reg = readw(uart->membase + UART011_CR);
> + switch (uart->adaptor) {
> + default:
> + reg |= UART011_CR_RTS
> + /* Hardware RTS unless throttling*/
> + | (uart->throttle_tx ? 0 : UART011_CR_RTSEN)
> + /* Hardware CTS unless throttling */
> + | (uart->throttle_tx ? 0 : UART011_CR_CTSEN);
> + writew(reg, uart->membase + UART011_CR);
> + break;
> + case SNDRV_SERIAL_MS124W_SA:
> + case SNDRV_SERIAL_MS124W_MB:
> + /* FIXME: MS-124W can draw power from RTS and DTR if they
> + are in opposite states. */
> + break;
> + case SNDRV_SERIAL_MS124T:
> + /* FIXME: MS-124T can draw power from RTS and/or DTR (preferably
> + both) if they are both asserted. */
> + break;
> + }
> +
> + uart->control_reg = reg;
> +
> + writew(UART011_RXIC /* Clear corresponting interrupts */
> + | UART011_TXIC
> + | UART011_RTIC
> + , uart->membase + UART011_ICR);
> +
> + if (uart->adaptor == SNDRV_SERIAL_MS124W_SA) {
> + /* FIXME: Enable RX data and Modem Status */
> + } else if (uart->adaptor == SNDRV_SERIAL_GENERIC) {
> + writew(UART011_RXIM /* Enable RX FIFO interrupt */
> + | UART011_RTIM /* Enable RX timeout interrupt */
> + /* Enable TX FIFO if not using throttling */
> + | (uart->throttle_tx ? 0 : UART011_TXIM)
> + , uart->membase + UART011_IMSC);
> + } else {
> + /* FIXME: Enable RX data and THRI */
> + }
> +}
> +
> +static void snd_uart_pl011_do_close(struct snd_uart_pl011 * uart)
> +{
> + writew(0, uart->membase + UART011_IMSC); /* Interrupt enable Register
> */
> + writew(0xffff, uart->membase + UART011_ICR);
> +
> + switch (uart->adaptor) {
> + default:
> + /* Disable everything */
> + writew(0, uart->membase + UART011_CR);
> + break;
> + case SNDRV_SERIAL_MS124W_SA:
> + case SNDRV_SERIAL_MS124W_MB:
> + /* FIXME: MS-124W can draw power from RTS and DTR if they
> + are in opposite states; leave it powered. */
> + break;
> + case SNDRV_SERIAL_MS124T:
> + /* FIXME: MS-124T can draw power from RTS and/or DTR (preferably
> + both) if they are both asserted; leave it powered. */
> + break;
> + }
> +
> +}
> +
> +static int snd_uart_pl011_input_open(struct snd_rawmidi_substream
> *substream)
> +{
> + unsigned long flags;
> + struct snd_uart_pl011 *uart = substream->rmidi->private_data;
> +
> + spin_lock_irqsave(&uart->open_lock, flags);
> + if (uart->filemode == SERIAL_MODE_NOT_OPENED)
> + snd_uart_pl011_do_open(uart);
> + uart->filemode |= SERIAL_MODE_INPUT_OPEN;
> + uart->midi_input[substream->number] = substream;
> + spin_unlock_irqrestore(&uart->open_lock, flags);
> + return 0;
> +}
> +
> +static int snd_uart_pl011_input_close(struct snd_rawmidi_substream
> *substream)
> +{
> + unsigned long flags;
> + struct snd_uart_pl011 *uart = substream->rmidi->private_data;
> +
> + spin_lock_irqsave(&uart->open_lock, flags);
> + uart->filemode &= ~SERIAL_MODE_INPUT_OPEN;
> + uart->midi_input[substream->number] = NULL;
> + if (uart->filemode == SERIAL_MODE_NOT_OPENED)
> + snd_uart_pl011_do_close(uart);
> + spin_unlock_irqrestore(&uart->open_lock, flags);
> + return 0;
> +}
> +
> +static void snd_uart_pl011_input_trigger(struct snd_rawmidi_substream
> *substream,
> + int up)
> +{
> + unsigned long flags;
> + struct snd_uart_pl011 *uart = substream->rmidi->private_data;
> +
> + spin_lock_irqsave(&uart->open_lock, flags);
> + if (up)
> + uart->filemode |= SERIAL_MODE_INPUT_TRIGGERED;
> + else
> + uart->filemode &= ~SERIAL_MODE_INPUT_TRIGGERED;
> + spin_unlock_irqrestore(&uart->open_lock, flags);
> +}
> +
> +static int snd_uart_pl011_output_open(struct snd_rawmidi_substream
> *substream)
> +{
> + unsigned long flags;
> + struct snd_uart_pl011 *uart = substream->rmidi->private_data;
> +
> + spin_lock_irqsave(&uart->open_lock, flags);
> + if (uart->filemode == SERIAL_MODE_NOT_OPENED)
> + snd_uart_pl011_do_open(uart);
> + uart->filemode |= SERIAL_MODE_OUTPUT_OPEN;
> + uart->midi_output[substream->number] = substream;
> + spin_unlock_irqrestore(&uart->open_lock, flags);
> + return 0;
> +};
> +
> +static int snd_uart_pl011_output_close(struct snd_rawmidi_substream
> *substream)
> +{
> + unsigned long flags;
> + struct snd_uart_pl011 *uart = substream->rmidi->private_data;
> +
> + spin_lock_irqsave(&uart->open_lock, flags);
> + uart->filemode &= ~SERIAL_MODE_OUTPUT_OPEN;
> + uart->midi_output[substream->number] = NULL;
> + if (uart->filemode == SERIAL_MODE_NOT_OPENED)
> + snd_uart_pl011_do_close(uart);
> + spin_unlock_irqrestore(&uart->open_lock, flags);
> + return 0;
> +};
> +
> +static inline int snd_uart_pl011_buffer_can_write(struct snd_uart_pl011
> *uart,
> + int Num)
> +{
> + if (uart->buff_in_count + Num < TX_BUFF_SIZE)
> + return 1;
> + else
> + return 0;
> +}
> +
> +static inline int snd_uart_pl011_write_buffer(struct snd_uart_pl011
> *uart,
> + unsigned char byte)
> +{
> + unsigned short buff_in = uart->buff_in;
> + if (uart->buff_in_count < TX_BUFF_SIZE) {
> + uart->tx_buff[buff_in] = byte;
> + buff_in++;
> + buff_in &= TX_BUFF_MASK;
> + uart->buff_in = buff_in;
> + uart->buff_in_count++;
> + if (uart->throttle_tx)
> + snd_uart_pl011_start_timer(uart);
> + return 1;
> + } else
> + return 0;
> +}
> +
> +static int snd_uart_pl011_output_byte(struct snd_uart_pl011 *uart,
> + struct snd_rawmidi_substream *substream,
> + unsigned char midi_byte)
> +{
> + if ((uart->buff_in_count == 0) && !uart->throttle_tx) {
> + /* Tx Buffer Empty - try to write immediately */
> + if (readw(uart->membase + UART01x_FR) & UART011_FR_TXFE) {
> + uart->fifo_count = 1;
> + writeb(midi_byte, uart->membase + UART01x_DR);
> + } else {
> + if (uart->fifo_count < uart->fifo_limit) {
> + uart->fifo_count++;
> + writeb(midi_byte, uart->membase + UART01x_DR);
> + } else {
> + /* Cannot write (buffer empty) -
> + * put char in buffer */
> + snd_uart_pl011_write_buffer(uart, midi_byte);
> + }
> + }
> + } else {
> + if (!snd_uart_pl011_write_buffer(uart, midi_byte)) {
> + snd_printk(KERN_WARNING
> + "%s: Buffer overrun on device at 0x%lx\n",
> + uart->rmidi->name, uart->mapbase);
> + return 0;
> + }
> + }
> + return 1;
> +}
> +
> +static void snd_uart_pl011_output_write(struct snd_rawmidi_substream
> *substream)
> +{
> + unsigned char midi_byte, addr_byte;
> + struct snd_uart_pl011 *uart = substream->rmidi->private_data;
> + char first;
> + static unsigned long lasttime = 0;
> +
> + /* Interrupts are disabled during the updating of the tx_buff,
> + * since it is 'bad' to have two processes updating the same
> + * variables (ie buff_in & buff_out)
> + */
> +
> + if (uart->adaptor == SNDRV_SERIAL_MS124W_MB) {
> + while (1) {
> + /* buffer full? */
> + /* in this mode we need two bytes of space */
> + if (uart->buff_in_count > TX_BUFF_SIZE - 2)
> + break;
> + if (snd_rawmidi_transmit(substream, &midi_byte, 1) != 1)
> + break;
> +#ifdef SNDRV_SERIAL_MS124W_MB_NOCOMBO
> + /* select exactly one of the four ports */
> + addr_byte = (1 << (substream->number + 4)) | 0x08;
> +#else
> + /* select any combination of the four ports */
> + addr_byte = (substream->number << 4) | 0x08;
> + /* ...except none */
> + if (addr_byte == 0x08)
> + addr_byte = 0xf8;
> +#endif
> + snd_uart_pl011_output_byte(uart, substream, addr_byte);
> + /* send midi byte */
> + snd_uart_pl011_output_byte(uart, substream, midi_byte);
> + }
> + } else {
> + first = 0;
> + while (snd_rawmidi_transmit_peek(substream, &midi_byte, 1) == 1) {
> + /* Also send F5 after 3 seconds with no data
> + * to handle device disconnect */
> + if (first == 0 &&
> + (uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS ||
> + uart->adaptor == SNDRV_SERIAL_GENERIC) &&
> + (uart->prev_out != substream->number ||
> + time_after(jiffies, lasttime + 3*HZ))) {
> +
> + if (snd_uart_pl011_buffer_can_write(uart, 3)) {
> + /* Roland Soundcanvas part selection */
> + /* If this substream of the data is
> + * different previous substream
> + * in this uart, send the change part
> + * event
> + */
> + uart->prev_out = substream->number;
> + /* change part */
> + snd_uart_pl011_output_byte(uart, substream,
> + 0xf5);
> + /* data */
> + snd_uart_pl011_output_byte(uart, substream,
> + uart->prev_out + 1);
> + /* If midi_byte is a data byte,
> + * send the previous status byte */
> + if (midi_byte < 0x80 &&
> + uart->adaptor == SNDRV_SERIAL_SOUNDCANVAS)
> + snd_uart_pl011_output_byte(uart, substream,
> uart->prev_status[uart->prev_out]);
> + } else if (!uart->drop_on_full)
> + break;
> +
> + }
> +
> + /* send midi byte */
> + if (!snd_uart_pl011_output_byte(uart, substream, midi_byte) &&
> + !uart->drop_on_full )
> + break;
> +
> + if (midi_byte >= 0x80 && midi_byte < 0xf0)
> + uart->prev_status[uart->prev_out] = midi_byte;
> + first = 1;
> +
> + snd_rawmidi_transmit_ack( substream, 1 );
> + }
> + lasttime = jiffies;
> + }
> +}
> +
> +static void snd_uart_pl011_output_trigger(struct snd_rawmidi_substream
> *substream,
> + int up)
> +{
> + unsigned long flags;
> + struct snd_uart_pl011 *uart = substream->rmidi->private_data;
> +
> + spin_lock_irqsave(&uart->open_lock, flags);
> + if (up) {
> + uart->filemode |= SERIAL_MODE_OUTPUT_TRIGGERED;
> + snd_uart_pl011_output_write(substream);
> + } else {
> + uart->filemode &= ~SERIAL_MODE_OUTPUT_TRIGGERED;
> + snd_uart_pl011_del_timer(uart);
> + }
> + spin_unlock_irqrestore(&uart->open_lock, flags);
> +}
> +
> +static void snd_uart_pl011_output_drain(struct snd_rawmidi_substream
> *substream)
> +{
> + unsigned long flags;
> + struct snd_uart_pl011 *uart = substream->rmidi->private_data;
> + DEFINE_WAIT(wait);
> + long timeout;
> +
> + spin_lock_irqsave(&uart->open_lock, flags);
> +
> + if (uart->filemode == SERIAL_MODE_NOT_OPENED) {
> + spin_unlock_irqrestore(&uart->open_lock, flags);
> + return;
> + }
> +
> + if (uart->buff_in_count || uart->fifo_count) {
> + uart->draining++;
> + do {
> + timeout = msecs_to_jiffies(50);
> + prepare_to_wait(&uart->drain_wait, &wait,
> + TASK_UNINTERRUPTIBLE);
> + spin_unlock_irqrestore(&uart->open_lock, flags);
> + timeout = schedule_timeout(timeout);
> + spin_lock_irqsave(&uart->open_lock, flags);
> + } while ((uart->buff_in_count || uart->fifo_count) && timeout);
> + uart->draining = 0;
> + finish_wait(&uart->drain_wait, &wait);
> + }
> + spin_unlock_irqrestore(&uart->open_lock, flags);
> +}
> +
> +static struct snd_rawmidi_ops snd_uart_pl011_output =
> +{
> + .open = snd_uart_pl011_output_open,
> + .close = snd_uart_pl011_output_close,
> + .trigger = snd_uart_pl011_output_trigger,
> + .drain = snd_uart_pl011_output_drain,
> +};
> +
> +static struct snd_rawmidi_ops snd_uart_pl011_input =
> +{
> + .open = snd_uart_pl011_input_open,
> + .close = snd_uart_pl011_input_close,
> + .trigger = snd_uart_pl011_input_trigger,
> +};
> +
> +static int snd_uart_pl011_free(struct snd_uart_pl011 *uart)
> +{
> + if (uart->irq >= 0)
> + free_irq(uart->irq, uart);
> + if (!IS_ERR(uart->clk) && uart->clk) clk_disable_unprepare(uart->clk);
> + if (uart->dev) pinctrl_pm_select_sleep_state(&uart->dev->dev);
> + release_and_free_resource(uart->res_base);
> + kfree(uart);
> + return 0;
> +};
> +
> +static int snd_uart_pl011_dev_free(struct snd_device *device)
> +{
> + struct snd_uart_pl011 *uart = device->device_data;
> + return snd_uart_pl011_free(uart);
> +}
> +
> +static int snd_uart_pl011_create(struct snd_card *card,
> + struct amba_device *devptr,
> + unsigned int speed,
> + int adaptor,
> + int droponfull,
> + int throttle_tx,
> + int throttle_delay,
> + int flow_control,
> + int fifo_limit,
> + struct snd_uart_pl011 **ruart)
> +{
> + static struct snd_device_ops ops = {
> + .dev_free = snd_uart_pl011_dev_free,
> + };
> + struct snd_uart_pl011 *uart;
> + int err;
> + void __iomem *membase;
> +
> +
> + if ((uart = kzalloc(sizeof(*uart), GFP_KERNEL)) == NULL)
> + return -ENOMEM;
> +
> + uart->irq = -1;
> + uart->res_base = request_mem_region(devptr->res.start,
> + resource_size(&devptr->res), "Serial MIDI");
> +
> + if (uart->res_base == NULL) {
> + snd_printk(KERN_ERR "pl011: can't grab port\n");
> + return -EBUSY;
> + }
> +
> + membase = devm_ioremap(&devptr->dev, devptr->res.start,
> + resource_size(&devptr->res));
> +
> + if (!membase) {
> + snd_printk(KERN_ERR "pl011: ioremap error\n");
> + snd_uart_pl011_free(uart);
> + return -ENOMEM;
> + }
> +
> + uart->clk = devm_clk_get(&devptr->dev, NULL);
> + if (IS_ERR(uart->clk)) {
> + snd_printk(KERN_ERR "pl011: unable to get clock resource\n");
> + snd_uart_pl011_free(uart);
> + return -ENODEV;
> + }
> +
> + clk_prepare_enable(uart->clk);
> +
> + uart->adaptor = adaptor;
> + uart->card = card;
> + spin_lock_init(&uart->open_lock);
> + uart->membase = membase;
> + uart->mapbase = devptr->res.start;
> + uart->drop_on_full = droponfull;
> + uart->throttle_tx = throttle_tx;
> + uart->throttle_delay = ns_to_ktime(throttle_delay * 1000);
> + uart->flow_control = flow_control;
> + uart->fifo_limit = fifo_limit;
> + uart->speed = speed;
> + uart->prev_out = -1;
> + memset(uart->prev_status, 0x80,
> + sizeof(unsigned char) * SNDRV_SERIAL_MAX_OUTS);
> + hrtimer_init(&uart->buffer_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
> + uart->buffer_timer.function = snd_uart_pl011_buffer_timer;
> +
> + if (snd_uart_pl011_detect(uart) == 0) {
> + snd_printk(KERN_ERR "no UART detected\n");
> + snd_uart_pl011_free(uart);
> + return -ENODEV;
> + }
> +
> + if (request_irq(devptr->irq[0], snd_uart_pl011_interrupt,
> + 0, "Serial MIDI", uart)) {
> + snd_printk(KERN_ERR "unable to request IRQ\n");
> + snd_uart_pl011_free(uart);
> + return -ENODEV;
> + }
> + uart->irq = devptr->irq[0];
> +
> + init_waitqueue_head(&uart->drain_wait);
> +
> + snd_printk(KERN_INFO "Detected PL011 at 0x%lx using irq: %i\n",
> + uart->mapbase, uart->irq);
> +
> + /* Register device */
> + if ((err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, uart, &ops)) < 0)
> {
> + snd_uart_pl011_free(uart);
> + return err;
> + }
> +
> + /* FIXME: CTS/RTS pins */
> + uart->dev = devptr;
> + pinctrl_pm_select_default_state(&uart->dev->dev);
> +
> + switch (uart->adaptor) {
> + case SNDRV_SERIAL_MS124W_SA:
> + case SNDRV_SERIAL_MS124W_MB:
> + /* FIXME: MS-124W can draw power from RTS and DTR if they
> + are in opposite states. */
> + break;
> + case SNDRV_SERIAL_MS124T:
> + /* FIXME: MS-124T can draw power from RTS and/or DTR (preferably
> + both) if they are asserted. */
> + break;
> + default:
> + break;
> + }
> +
> + if (ruart)
> + *ruart = uart;
> +
> + return 0;
> +}
> +
> +static void snd_uart_pl011_substreams(struct snd_rawmidi_str *stream)
> +{
> + struct snd_rawmidi_substream *substream;
> +
> + list_for_each_entry(substream, &stream->substreams, list) {
> + sprintf(substream->name, "Serial MIDI %d", substream->number + 1);
> + }
> +}
> +
> +static int snd_uart_pl011_rmidi(struct snd_uart_pl011 *uart, int
> device,
> + int outs, int ins,
> + struct snd_rawmidi **rmidi)
> +{
> + struct snd_rawmidi *rrawmidi;
> + int err;
> +
> + err = snd_rawmidi_new(uart->card, "UART Serial MIDI", device,
> + outs, ins, &rrawmidi);
> + if (err < 0)
> + return err;
> + snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_INPUT,
> + &snd_uart_pl011_input);
> + snd_rawmidi_set_ops(rrawmidi, SNDRV_RAWMIDI_STREAM_OUTPUT,
> + &snd_uart_pl011_output);
> + strcpy(rrawmidi->name, "Serial MIDI");
> +
> snd_uart_pl011_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_OUTPUT]);
> +
> snd_uart_pl011_substreams(&rrawmidi->streams[SNDRV_RAWMIDI_STREAM_INPUT]);
> + rrawmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
> + SNDRV_RAWMIDI_INFO_INPUT |
> + SNDRV_RAWMIDI_INFO_DUPLEX;
> + rrawmidi->private_data = uart;
> + if (rmidi)
> + *rmidi = rrawmidi;
> + return 0;
> +}
> +
> +static int snd_serial_probe(struct amba_device *devptr,
> + const struct amba_id *id)
> +{
> + struct snd_card *card;
> + struct snd_uart_pl011 *uart;
> + int err;
> +
> + switch (adaptor) {
> + case SNDRV_SERIAL_SOUNDCANVAS:
> + ins = 1;
> + break;
> + case SNDRV_SERIAL_MS124T:
> + case SNDRV_SERIAL_MS124W_SA:
> + outs = 1;
> + ins = 1;
> + break;
> + case SNDRV_SERIAL_MS124W_MB:
> + outs = 16;
> + ins = 1;
> + break;
> + case SNDRV_SERIAL_GENERIC:
> + break;
> + default:
> + snd_printk(KERN_ERR
> + "Adaptor type is out of range 0-%d (%d)\n",
> + SNDRV_SERIAL_MAX_ADAPTOR, adaptor);
> + return -ENODEV;
> + }
> +
> + if (outs < 1 || outs > SNDRV_SERIAL_MAX_OUTS) {
> + snd_printk(KERN_ERR
> + "Count of outputs is out of range 1-%d (%d)\n",
> + SNDRV_SERIAL_MAX_OUTS, outs);
> + return -ENODEV;
> + }
> +
> + if (ins < 1 || ins > SNDRV_SERIAL_MAX_INS) {
> + snd_printk(KERN_ERR
> + "Count of inputs is out of range 1-%d (%d)\n",
> + SNDRV_SERIAL_MAX_INS, ins);
> + return -ENODEV;
> + }
> +
> + err = snd_card_create(-1, NULL, THIS_MODULE, 0, &card);
> + if (err < 0)
> + return err;
> +
> + strcpy(card->driver, "Serial");
> + strcpy(card->shortname, "Serial MIDI (PL011)");
> +
> + if ((err = snd_uart_pl011_create(card, devptr,
> + speed,
> + adaptor,
> + droponfull,
> + throttle_tx,
> + throttle_delay,
> + flow_control,
> + fifo_limit,
> + &uart)) < 0)
> + goto _err;
> +
> + err = snd_uart_pl011_rmidi(uart, 0, outs, ins, &uart->rmidi);
> + if (err < 0)
> + goto _err;
> +
> + sprintf(card->longname, "%s [%s] at %#lx, irq %d",
> + card->shortname,
> + adaptor_names[uart->adaptor],
> + (unsigned long) uart->membase,
> + uart->irq);
> +
> + snd_card_set_dev(card, &devptr->dev);
> +
> + if ((err = snd_card_register(card)) < 0)
> + goto _err;
> +
> + amba_set_drvdata(devptr, card);
> + return 0;
> +
> + _err:
> + snd_card_free(card);
> + return err;
> +}
> +
> +static int snd_serial_remove(struct amba_device *devptr)
> +{
> + snd_card_free(amba_get_drvdata(devptr));
> + return 0;
> +}
> +
> +#define SND_SERIAL_DRIVER "snd_serial_pl011"
> +
> +static struct amba_id snd_serial_ids[] = {
> + {
> + .id = 0x00041011,
> + .mask = 0x000fffff,
> + },
> + { 0, 0 },
> +};
> +
> +static struct amba_driver snd_serial_driver = {
> + .drv = {
> + .name = SND_SERIAL_DRIVER,
> + },
> + .id_table = snd_serial_ids,
> + .probe = snd_serial_probe,
> + .remove = snd_serial_remove,
> +};
> +
> +static int __init alsa_card_serial_init(void)
> +{
> + snd_printk(KERN_INFO "snd-serial-pl011: PL011 based MIDI device\n");
> + return amba_driver_register(&snd_serial_driver);
> +}
> +
> +static void __exit alsa_card_serial_exit(void)
> +{
> + amba_driver_unregister(&snd_serial_driver);
> +}
> +
> +module_init(alsa_card_serial_init)
> +module_exit(alsa_card_serial_exit)
>
>
>
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