2 * Freescale QUICC Engine UART device driver
4 * Author: Timur Tabi <timur@freescale.com>
6 * Copyright 2007 Freescale Semiconductor, Inc. This file is licensed under
7 * the terms of the GNU General Public License version 2. This program
8 * is licensed "as is" without any warranty of any kind, whether express
11 * This driver adds support for UART devices via Freescale's QUICC Engine
12 * found on some Freescale SOCs.
14 * If Soft-UART support is needed but not already present, then this driver
15 * will request and upload the "Soft-UART" microcode upon probe. The
16 * filename of the microcode should be fsl_qe_ucode_uart_X_YZ.bin, where "X"
17 * is the name of the SOC (e.g. 8323), and YZ is the revision of the SOC,
18 * (e.g. "11" for 1.1).
21 #include <linux/module.h>
22 #include <linux/serial.h>
23 #include <linux/serial_core.h>
25 #include <linux/of_platform.h>
26 #include <linux/dma-mapping.h>
28 #include <linux/fs_uart_pd.h>
29 #include <asm/ucc_slow.h>
31 #include <linux/firmware.h>
35 * The GUMR flag for Soft UART. This would normally be defined in qe.h,
36 * but Soft-UART is a hack and we want to keep everything related to it in
39 #define UCC_SLOW_GUMR_H_SUART 0x00004000 /* Soft-UART */
42 * soft_uart is 1 if we need to use Soft-UART mode
46 * firmware_loaded is 1 if the firmware has been loaded, 0 otherwise.
48 static int firmware_loaded;
50 /* Enable this macro to configure all serial ports in internal loopback
52 /* #define LOOPBACK */
54 /* The major and minor device numbers are defined in
55 * http://www.lanana.org/docs/device-list/devices-2.6+.txt. For the QE
56 * UART, we have major number 204 and minor numbers 46 - 49, which are the
57 * same as for the CPM2. This decision was made because no Freescale part
58 * has both a CPM and a QE.
60 #define SERIAL_QE_MAJOR 204
61 #define SERIAL_QE_MINOR 46
63 /* Since we only have minor numbers 46 - 49, there is a hard limit of 4 ports */
64 #define UCC_MAX_UART 4
66 /* The number of buffer descriptors for receiving characters. */
69 /* The number of buffer descriptors for transmitting characters. */
72 /* The maximum size of the character buffer for a single RX BD. */
73 #define RX_BUF_SIZE 32
75 /* The maximum size of the character buffer for a single TX BD. */
76 #define TX_BUF_SIZE 32
79 * The number of jiffies to wait after receiving a close command before the
80 * device is actually closed. This allows the last few characters to be
83 #define UCC_WAIT_CLOSING 100
85 struct ucc_uart_pram {
86 struct ucc_slow_pram common;
87 u8 res1[8]; /* reserved */
88 __be16 maxidl; /* Maximum idle chars */
89 __be16 idlc; /* temp idle counter */
90 __be16 brkcr; /* Break count register */
91 __be16 parec; /* receive parity error counter */
92 __be16 frmec; /* receive framing error counter */
93 __be16 nosec; /* receive noise counter */
94 __be16 brkec; /* receive break condition counter */
95 __be16 brkln; /* last received break length */
96 __be16 uaddr[2]; /* UART address character 1 & 2 */
97 __be16 rtemp; /* Temp storage */
98 __be16 toseq; /* Transmit out of sequence char */
99 __be16 cchars[8]; /* control characters 1-8 */
100 __be16 rccm; /* receive control character mask */
101 __be16 rccr; /* receive control character register */
102 __be16 rlbc; /* receive last break character */
103 __be16 res2; /* reserved */
104 __be32 res3; /* reserved, should be cleared */
105 u8 res4; /* reserved, should be cleared */
106 u8 res5[3]; /* reserved, should be cleared */
107 __be32 res6; /* reserved, should be cleared */
108 __be32 res7; /* reserved, should be cleared */
109 __be32 res8; /* reserved, should be cleared */
110 __be32 res9; /* reserved, should be cleared */
111 __be32 res10; /* reserved, should be cleared */
112 __be32 res11; /* reserved, should be cleared */
113 __be32 res12; /* reserved, should be cleared */
114 __be32 res13; /* reserved, should be cleared */
115 /* The rest is for Soft-UART only */
116 __be16 supsmr; /* 0x90, Shadow UPSMR */
117 __be16 res92; /* 0x92, reserved, initialize to 0 */
118 __be32 rx_state; /* 0x94, RX state, initialize to 0 */
119 __be32 rx_cnt; /* 0x98, RX count, initialize to 0 */
120 u8 rx_length; /* 0x9C, Char length, set to 1+CL+PEN+1+SL */
121 u8 rx_bitmark; /* 0x9D, reserved, initialize to 0 */
122 u8 rx_temp_dlst_qe; /* 0x9E, reserved, initialize to 0 */
123 u8 res14[0xBC - 0x9F]; /* reserved */
124 __be32 dump_ptr; /* 0xBC, Dump pointer */
125 __be32 rx_frame_rem; /* 0xC0, reserved, initialize to 0 */
126 u8 rx_frame_rem_size; /* 0xC4, reserved, initialize to 0 */
127 u8 tx_mode; /* 0xC5, mode, 0=AHDLC, 1=UART */
128 __be16 tx_state; /* 0xC6, TX state */
129 u8 res15[0xD0 - 0xC8]; /* reserved */
130 __be32 resD0; /* 0xD0, reserved, initialize to 0 */
131 u8 resD4; /* 0xD4, reserved, initialize to 0 */
132 __be16 resD5; /* 0xD5, reserved, initialize to 0 */
133 } __attribute__ ((packed));
135 /* SUPSMR definitions, for Soft-UART only */
136 #define UCC_UART_SUPSMR_SL 0x8000
137 #define UCC_UART_SUPSMR_RPM_MASK 0x6000
138 #define UCC_UART_SUPSMR_RPM_ODD 0x0000
139 #define UCC_UART_SUPSMR_RPM_LOW 0x2000
140 #define UCC_UART_SUPSMR_RPM_EVEN 0x4000
141 #define UCC_UART_SUPSMR_RPM_HIGH 0x6000
142 #define UCC_UART_SUPSMR_PEN 0x1000
143 #define UCC_UART_SUPSMR_TPM_MASK 0x0C00
144 #define UCC_UART_SUPSMR_TPM_ODD 0x0000
145 #define UCC_UART_SUPSMR_TPM_LOW 0x0400
146 #define UCC_UART_SUPSMR_TPM_EVEN 0x0800
147 #define UCC_UART_SUPSMR_TPM_HIGH 0x0C00
148 #define UCC_UART_SUPSMR_FRZ 0x0100
149 #define UCC_UART_SUPSMR_UM_MASK 0x00c0
150 #define UCC_UART_SUPSMR_UM_NORMAL 0x0000
151 #define UCC_UART_SUPSMR_UM_MAN_MULTI 0x0040
152 #define UCC_UART_SUPSMR_UM_AUTO_MULTI 0x00c0
153 #define UCC_UART_SUPSMR_CL_MASK 0x0030
154 #define UCC_UART_SUPSMR_CL_8 0x0030
155 #define UCC_UART_SUPSMR_CL_7 0x0020
156 #define UCC_UART_SUPSMR_CL_6 0x0010
157 #define UCC_UART_SUPSMR_CL_5 0x0000
159 #define UCC_UART_TX_STATE_AHDLC 0x00
160 #define UCC_UART_TX_STATE_UART 0x01
161 #define UCC_UART_TX_STATE_X1 0x00
162 #define UCC_UART_TX_STATE_X16 0x80
164 #define UCC_UART_PRAM_ALIGNMENT 0x100
166 #define UCC_UART_SIZE_OF_BD UCC_SLOW_SIZE_OF_BD
167 #define NUM_CONTROL_CHARS 8
169 /* Private per-port data structure */
170 struct uart_qe_port {
171 struct uart_port port;
172 struct ucc_slow __iomem *uccp;
173 struct ucc_uart_pram __iomem *uccup;
174 struct ucc_slow_info us_info;
175 struct ucc_slow_private *us_private;
176 struct device_node *np;
177 unsigned int ucc_num; /* First ucc is 0, not 1 */
185 struct qe_bd *rx_bd_base;
186 struct qe_bd *rx_cur;
187 struct qe_bd *tx_bd_base;
188 struct qe_bd *tx_cur;
189 unsigned char *tx_buf;
190 unsigned char *rx_buf;
191 void *bd_virt; /* virtual address of the BD buffers */
192 dma_addr_t bd_dma_addr; /* bus address of the BD buffers */
193 unsigned int bd_size; /* size of BD buffer space */
196 static struct uart_driver ucc_uart_driver = {
197 .owner = THIS_MODULE,
198 .driver_name = "ucc_uart",
200 .major = SERIAL_QE_MAJOR,
201 .minor = SERIAL_QE_MINOR,
206 * Virtual to physical address translation.
208 * Given the virtual address for a character buffer, this function returns
209 * the physical (DMA) equivalent.
211 static inline dma_addr_t cpu2qe_addr(void *addr, struct uart_qe_port *qe_port)
213 if (likely((addr >= qe_port->bd_virt)) &&
214 (addr < (qe_port->bd_virt + qe_port->bd_size)))
215 return qe_port->bd_dma_addr + (addr - qe_port->bd_virt);
217 /* something nasty happened */
218 printk(KERN_ERR "%s: addr=%p\n", __func__, addr);
224 * Physical to virtual address translation.
226 * Given the physical (DMA) address for a character buffer, this function
227 * returns the virtual equivalent.
229 static inline void *qe2cpu_addr(dma_addr_t addr, struct uart_qe_port *qe_port)
232 if (likely((addr >= qe_port->bd_dma_addr) &&
233 (addr < (qe_port->bd_dma_addr + qe_port->bd_size))))
234 return qe_port->bd_virt + (addr - qe_port->bd_dma_addr);
236 /* something nasty happened */
237 printk(KERN_ERR "%s: addr=%x\n", __func__, addr);
243 * Return 1 if the QE is done transmitting all buffers for this port
245 * This function scans each BD in sequence. If we find a BD that is not
246 * ready (READY=1), then we return 0 indicating that the QE is still sending
247 * data. If we reach the last BD (WRAP=1), then we know we've scanned
248 * the entire list, and all BDs are done.
250 static unsigned int qe_uart_tx_empty(struct uart_port *port)
252 struct uart_qe_port *qe_port =
253 container_of(port, struct uart_qe_port, port);
254 struct qe_bd *bdp = qe_port->tx_bd_base;
257 if (in_be16(&bdp->status) & BD_SC_READY)
258 /* This BD is not done, so return "not done" */
261 if (in_be16(&bdp->status) & BD_SC_WRAP)
263 * This BD is done and it's the last one, so return
273 * Set the modem control lines
275 * Although the QE can control the modem control lines (e.g. CTS), we
276 * don't need that support. This function must exist, however, otherwise
277 * the kernel will panic.
279 void qe_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
284 * Get the current modem control line status
286 * Although the QE can control the modem control lines (e.g. CTS), this
287 * driver currently doesn't support that, so we always return Carrier
288 * Detect, Data Set Ready, and Clear To Send.
290 static unsigned int qe_uart_get_mctrl(struct uart_port *port)
292 return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
296 * Disable the transmit interrupt.
298 * Although this function is called "stop_tx", it does not actually stop
299 * transmission of data. Instead, it tells the QE to not generate an
300 * interrupt when the UCC is finished sending characters.
302 static void qe_uart_stop_tx(struct uart_port *port)
304 struct uart_qe_port *qe_port =
305 container_of(port, struct uart_qe_port, port);
307 clrbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_TX);
311 * Transmit as many characters to the HW as possible.
313 * This function will attempt to stuff of all the characters from the
314 * kernel's transmit buffer into TX BDs.
316 * A return value of non-zero indicates that it sucessfully stuffed all
317 * characters from the kernel buffer.
319 * A return value of zero indicates that there are still characters in the
320 * kernel's buffer that have not been transmitted, but there are no more BDs
321 * available. This function should be called again after a BD has been made
324 static int qe_uart_tx_pump(struct uart_qe_port *qe_port)
329 struct uart_port *port = &qe_port->port;
330 struct circ_buf *xmit = &port->info->xmit;
332 bdp = qe_port->rx_cur;
334 /* Handle xon/xoff */
336 /* Pick next descriptor and fill from buffer */
337 bdp = qe_port->tx_cur;
339 p = qe2cpu_addr(bdp->buf, qe_port);
342 out_be16(&bdp->length, 1);
343 setbits16(&bdp->status, BD_SC_READY);
345 if (in_be16(&bdp->status) & BD_SC_WRAP)
346 bdp = qe_port->tx_bd_base;
349 qe_port->tx_cur = bdp;
356 if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
357 qe_uart_stop_tx(port);
361 /* Pick next descriptor and fill from buffer */
362 bdp = qe_port->tx_cur;
364 while (!(in_be16(&bdp->status) & BD_SC_READY) &&
365 (xmit->tail != xmit->head)) {
367 p = qe2cpu_addr(bdp->buf, qe_port);
368 while (count < qe_port->tx_fifosize) {
369 *p++ = xmit->buf[xmit->tail];
370 xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
373 if (xmit->head == xmit->tail)
377 out_be16(&bdp->length, count);
378 setbits16(&bdp->status, BD_SC_READY);
381 if (in_be16(&bdp->status) & BD_SC_WRAP)
382 bdp = qe_port->tx_bd_base;
386 qe_port->tx_cur = bdp;
388 if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
389 uart_write_wakeup(port);
391 if (uart_circ_empty(xmit)) {
392 /* The kernel buffer is empty, so turn off TX interrupts. We
393 don't need to be told when the QE is finished transmitting
395 qe_uart_stop_tx(port);
403 * Start transmitting data
405 * This function will start transmitting any available data, if the port
406 * isn't already transmitting data.
408 static void qe_uart_start_tx(struct uart_port *port)
410 struct uart_qe_port *qe_port =
411 container_of(port, struct uart_qe_port, port);
413 /* If we currently are transmitting, then just return */
414 if (in_be16(&qe_port->uccp->uccm) & UCC_UART_UCCE_TX)
417 /* Otherwise, pump the port and start transmission */
418 if (qe_uart_tx_pump(qe_port))
419 setbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_TX);
423 * Stop transmitting data
425 static void qe_uart_stop_rx(struct uart_port *port)
427 struct uart_qe_port *qe_port =
428 container_of(port, struct uart_qe_port, port);
430 clrbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_RX);
434 * Enable status change interrupts
436 * We don't support status change interrupts, but we need to define this
437 * function otherwise the kernel will panic.
439 static void qe_uart_enable_ms(struct uart_port *port)
443 /* Start or stop sending break signal
445 * This function controls the sending of a break signal. If break_state=1,
446 * then we start sending a break signal. If break_state=0, then we stop
447 * sending the break signal.
449 static void qe_uart_break_ctl(struct uart_port *port, int break_state)
451 struct uart_qe_port *qe_port =
452 container_of(port, struct uart_qe_port, port);
455 ucc_slow_stop_tx(qe_port->us_private);
457 ucc_slow_restart_tx(qe_port->us_private);
460 /* ISR helper function for receiving character.
462 * This function is called by the ISR to handling receiving characters
464 static void qe_uart_int_rx(struct uart_qe_port *qe_port)
467 unsigned char ch, *cp;
468 struct uart_port *port = &qe_port->port;
469 struct tty_struct *tty = port->info->port.tty;
474 /* Just loop through the closed BDs and copy the characters into
477 bdp = qe_port->rx_cur;
479 status = in_be16(&bdp->status);
481 /* If this one is empty, then we assume we've read them all */
482 if (status & BD_SC_EMPTY)
485 /* get number of characters, and check space in RX buffer */
486 i = in_be16(&bdp->length);
488 /* If we don't have enough room in RX buffer for the entire BD,
489 * then we try later, which will be the next RX interrupt.
491 if (tty_buffer_request_room(tty, i) < i) {
492 dev_dbg(port->dev, "ucc-uart: no room in RX buffer\n");
497 cp = qe2cpu_addr(bdp->buf, qe_port);
499 /* loop through the buffer */
506 (BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV))
508 if (uart_handle_sysrq_char(port, ch))
512 tty_insert_flip_char(tty, ch, flg);
516 /* This BD is ready to be used again. Clear status. get next */
517 clrsetbits_be16(&bdp->status, BD_SC_BR | BD_SC_FR | BD_SC_PR |
518 BD_SC_OV | BD_SC_ID, BD_SC_EMPTY);
519 if (in_be16(&bdp->status) & BD_SC_WRAP)
520 bdp = qe_port->rx_bd_base;
526 /* Write back buffer pointer */
527 qe_port->rx_cur = bdp;
529 /* Activate BH processing */
530 tty_flip_buffer_push(tty);
534 /* Error processing */
538 if (status & BD_SC_BR)
540 if (status & BD_SC_PR)
541 port->icount.parity++;
542 if (status & BD_SC_FR)
543 port->icount.frame++;
544 if (status & BD_SC_OV)
545 port->icount.overrun++;
547 /* Mask out ignored conditions */
548 status &= port->read_status_mask;
550 /* Handle the remaining ones */
551 if (status & BD_SC_BR)
553 else if (status & BD_SC_PR)
555 else if (status & BD_SC_FR)
558 /* Overrun does not affect the current character ! */
559 if (status & BD_SC_OV)
560 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
569 * This interrupt handler is called after a BD is processed.
571 static irqreturn_t qe_uart_int(int irq, void *data)
573 struct uart_qe_port *qe_port = (struct uart_qe_port *) data;
574 struct ucc_slow __iomem *uccp = qe_port->uccp;
577 /* Clear the interrupts */
578 events = in_be16(&uccp->ucce);
579 out_be16(&uccp->ucce, events);
581 if (events & UCC_UART_UCCE_BRKE)
582 uart_handle_break(&qe_port->port);
584 if (events & UCC_UART_UCCE_RX)
585 qe_uart_int_rx(qe_port);
587 if (events & UCC_UART_UCCE_TX)
588 qe_uart_tx_pump(qe_port);
590 return events ? IRQ_HANDLED : IRQ_NONE;
593 /* Initialize buffer descriptors
595 * This function initializes all of the RX and TX buffer descriptors.
597 static void qe_uart_initbd(struct uart_qe_port *qe_port)
603 /* Set the physical address of the host memory buffers in the buffer
604 * descriptors, and the virtual address for us to work with.
606 bd_virt = qe_port->bd_virt;
607 bdp = qe_port->rx_bd_base;
608 qe_port->rx_cur = qe_port->rx_bd_base;
609 for (i = 0; i < (qe_port->rx_nrfifos - 1); i++) {
610 out_be16(&bdp->status, BD_SC_EMPTY | BD_SC_INTRPT);
611 out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port));
612 out_be16(&bdp->length, 0);
613 bd_virt += qe_port->rx_fifosize;
618 out_be16(&bdp->status, BD_SC_WRAP | BD_SC_EMPTY | BD_SC_INTRPT);
619 out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port));
620 out_be16(&bdp->length, 0);
622 /* Set the physical address of the host memory
623 * buffers in the buffer descriptors, and the
624 * virtual address for us to work with.
626 bd_virt = qe_port->bd_virt +
627 L1_CACHE_ALIGN(qe_port->rx_nrfifos * qe_port->rx_fifosize);
628 qe_port->tx_cur = qe_port->tx_bd_base;
629 bdp = qe_port->tx_bd_base;
630 for (i = 0; i < (qe_port->tx_nrfifos - 1); i++) {
631 out_be16(&bdp->status, BD_SC_INTRPT);
632 out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port));
633 out_be16(&bdp->length, 0);
634 bd_virt += qe_port->tx_fifosize;
638 /* Loopback requires the preamble bit to be set on the first TX BD */
640 setbits16(&qe_port->tx_cur->status, BD_SC_P);
643 out_be16(&bdp->status, BD_SC_WRAP | BD_SC_INTRPT);
644 out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port));
645 out_be16(&bdp->length, 0);
649 * Initialize a UCC for UART.
651 * This function configures a given UCC to be used as a UART device. Basic
652 * UCC initialization is handled in qe_uart_request_port(). This function
653 * does all the UART-specific stuff.
655 static void qe_uart_init_ucc(struct uart_qe_port *qe_port)
658 struct ucc_slow __iomem *uccp = qe_port->uccp;
659 struct ucc_uart_pram *uccup = qe_port->uccup;
663 /* First, disable TX and RX in the UCC */
664 ucc_slow_disable(qe_port->us_private, COMM_DIR_RX_AND_TX);
666 /* Program the UCC UART parameter RAM */
667 out_8(&uccup->common.rbmr, UCC_BMR_GBL | UCC_BMR_BO_BE);
668 out_8(&uccup->common.tbmr, UCC_BMR_GBL | UCC_BMR_BO_BE);
669 out_be16(&uccup->common.mrblr, qe_port->rx_fifosize);
670 out_be16(&uccup->maxidl, 0x10);
671 out_be16(&uccup->brkcr, 1);
672 out_be16(&uccup->parec, 0);
673 out_be16(&uccup->frmec, 0);
674 out_be16(&uccup->nosec, 0);
675 out_be16(&uccup->brkec, 0);
676 out_be16(&uccup->uaddr[0], 0);
677 out_be16(&uccup->uaddr[1], 0);
678 out_be16(&uccup->toseq, 0);
679 for (i = 0; i < 8; i++)
680 out_be16(&uccup->cchars[i], 0xC000);
681 out_be16(&uccup->rccm, 0xc0ff);
683 /* Configure the GUMR registers for UART */
685 /* Soft-UART requires a 1X multiplier for TX */
686 clrsetbits_be32(&uccp->gumr_l,
687 UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK |
688 UCC_SLOW_GUMR_L_RDCR_MASK,
689 UCC_SLOW_GUMR_L_MODE_UART | UCC_SLOW_GUMR_L_TDCR_1 |
690 UCC_SLOW_GUMR_L_RDCR_16);
692 clrsetbits_be32(&uccp->gumr_l,
693 UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK |
694 UCC_SLOW_GUMR_L_RDCR_MASK,
695 UCC_SLOW_GUMR_L_MODE_UART | UCC_SLOW_GUMR_L_TDCR_16 |
696 UCC_SLOW_GUMR_L_RDCR_16);
698 clrsetbits_be32(&uccp->gumr_h, UCC_SLOW_GUMR_H_RFW,
699 UCC_SLOW_GUMR_H_TRX | UCC_SLOW_GUMR_H_TTX);
702 clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_DIAG_MASK,
703 UCC_SLOW_GUMR_L_DIAG_LOOP);
704 clrsetbits_be32(&uccp->gumr_h,
705 UCC_SLOW_GUMR_H_CTSP | UCC_SLOW_GUMR_H_RSYN,
706 UCC_SLOW_GUMR_H_CDS);
709 /* Enable rx interrupts and clear all pending events. */
710 out_be16(&uccp->uccm, 0);
711 out_be16(&uccp->ucce, 0xffff);
712 out_be16(&uccp->udsr, 0x7e7e);
714 /* Initialize UPSMR */
715 out_be16(&uccp->upsmr, 0);
718 out_be16(&uccup->supsmr, 0x30);
719 out_be16(&uccup->res92, 0);
720 out_be32(&uccup->rx_state, 0);
721 out_be32(&uccup->rx_cnt, 0);
722 out_8(&uccup->rx_bitmark, 0);
723 out_8(&uccup->rx_length, 10);
724 out_be32(&uccup->dump_ptr, 0x4000);
725 out_8(&uccup->rx_temp_dlst_qe, 0);
726 out_be32(&uccup->rx_frame_rem, 0);
727 out_8(&uccup->rx_frame_rem_size, 0);
728 /* Soft-UART requires TX to be 1X */
729 out_8(&uccup->tx_mode,
730 UCC_UART_TX_STATE_UART | UCC_UART_TX_STATE_X1);
731 out_be16(&uccup->tx_state, 0);
732 out_8(&uccup->resD4, 0);
733 out_be16(&uccup->resD5, 0);
736 * Enable receive and transmit.
739 /* From the microcode errata:
740 * 1.GUMR_L register, set mode=0010 (QMC).
741 * 2.Set GUMR_H[17] bit. (UART/AHDLC mode).
742 * 3.Set GUMR_H[19:20] (Transparent mode)
743 * 4.Clear GUMR_H[26] (RFW)
745 * 6.Receiver must use 16x over sampling
747 clrsetbits_be32(&uccp->gumr_l,
748 UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK |
749 UCC_SLOW_GUMR_L_RDCR_MASK,
750 UCC_SLOW_GUMR_L_MODE_QMC | UCC_SLOW_GUMR_L_TDCR_16 |
751 UCC_SLOW_GUMR_L_RDCR_16);
753 clrsetbits_be32(&uccp->gumr_h,
754 UCC_SLOW_GUMR_H_RFW | UCC_SLOW_GUMR_H_RSYN,
755 UCC_SLOW_GUMR_H_SUART | UCC_SLOW_GUMR_H_TRX |
756 UCC_SLOW_GUMR_H_TTX | UCC_SLOW_GUMR_H_TFL);
759 clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_DIAG_MASK,
760 UCC_SLOW_GUMR_L_DIAG_LOOP);
761 clrbits32(&uccp->gumr_h, UCC_SLOW_GUMR_H_CTSP |
762 UCC_SLOW_GUMR_H_CDS);
765 cecr_subblock = ucc_slow_get_qe_cr_subblock(qe_port->ucc_num);
766 qe_issue_cmd(QE_INIT_TX_RX, cecr_subblock,
767 QE_CR_PROTOCOL_UNSPECIFIED, 0);
772 * Initialize the port.
774 static int qe_uart_startup(struct uart_port *port)
776 struct uart_qe_port *qe_port =
777 container_of(port, struct uart_qe_port, port);
781 * If we're using Soft-UART mode, then we need to make sure the
782 * firmware has been uploaded first.
784 if (soft_uart && !firmware_loaded) {
785 dev_err(port->dev, "Soft-UART firmware not uploaded\n");
789 qe_uart_initbd(qe_port);
790 qe_uart_init_ucc(qe_port);
792 /* Install interrupt handler. */
793 ret = request_irq(port->irq, qe_uart_int, IRQF_SHARED, "ucc-uart",
796 dev_err(port->dev, "could not claim IRQ %u\n", port->irq);
801 setbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_RX);
802 ucc_slow_enable(qe_port->us_private, COMM_DIR_RX_AND_TX);
810 static void qe_uart_shutdown(struct uart_port *port)
812 struct uart_qe_port *qe_port =
813 container_of(port, struct uart_qe_port, port);
814 struct ucc_slow __iomem *uccp = qe_port->uccp;
815 unsigned int timeout = 20;
817 /* Disable RX and TX */
819 /* Wait for all the BDs marked sent */
820 while (!qe_uart_tx_empty(port)) {
822 dev_warn(port->dev, "shutdown timeout\n");
825 set_current_state(TASK_UNINTERRUPTIBLE);
829 if (qe_port->wait_closing) {
830 /* Wait a bit longer */
831 set_current_state(TASK_UNINTERRUPTIBLE);
832 schedule_timeout(qe_port->wait_closing);
836 ucc_slow_disable(qe_port->us_private, COMM_DIR_RX_AND_TX);
837 clrbits16(&uccp->uccm, UCC_UART_UCCE_TX | UCC_UART_UCCE_RX);
839 /* Shut them really down and reinit buffer descriptors */
840 ucc_slow_graceful_stop_tx(qe_port->us_private);
841 qe_uart_initbd(qe_port);
843 free_irq(port->irq, qe_port);
847 * Set the serial port parameters.
849 static void qe_uart_set_termios(struct uart_port *port,
850 struct ktermios *termios, struct ktermios *old)
852 struct uart_qe_port *qe_port =
853 container_of(port, struct uart_qe_port, port);
854 struct ucc_slow __iomem *uccp = qe_port->uccp;
857 u16 upsmr = in_be16(&uccp->upsmr);
858 struct ucc_uart_pram __iomem *uccup = qe_port->uccup;
859 u16 supsmr = in_be16(&uccup->supsmr);
860 u8 char_length = 2; /* 1 + CL + PEN + 1 + SL */
862 /* Character length programmed into the mode register is the
863 * sum of: 1 start bit, number of data bits, 0 or 1 parity bit,
864 * 1 or 2 stop bits, minus 1.
865 * The value 'bits' counts this for us.
869 upsmr &= UCC_UART_UPSMR_CL_MASK;
870 supsmr &= UCC_UART_SUPSMR_CL_MASK;
872 switch (termios->c_cflag & CSIZE) {
874 upsmr |= UCC_UART_UPSMR_CL_5;
875 supsmr |= UCC_UART_SUPSMR_CL_5;
879 upsmr |= UCC_UART_UPSMR_CL_6;
880 supsmr |= UCC_UART_SUPSMR_CL_6;
884 upsmr |= UCC_UART_UPSMR_CL_7;
885 supsmr |= UCC_UART_SUPSMR_CL_7;
888 default: /* case CS8 */
889 upsmr |= UCC_UART_UPSMR_CL_8;
890 supsmr |= UCC_UART_SUPSMR_CL_8;
895 /* If CSTOPB is set, we want two stop bits */
896 if (termios->c_cflag & CSTOPB) {
897 upsmr |= UCC_UART_UPSMR_SL;
898 supsmr |= UCC_UART_SUPSMR_SL;
899 char_length++; /* + SL */
902 if (termios->c_cflag & PARENB) {
903 upsmr |= UCC_UART_UPSMR_PEN;
904 supsmr |= UCC_UART_SUPSMR_PEN;
905 char_length++; /* + PEN */
907 if (!(termios->c_cflag & PARODD)) {
908 upsmr &= ~(UCC_UART_UPSMR_RPM_MASK |
909 UCC_UART_UPSMR_TPM_MASK);
910 upsmr |= UCC_UART_UPSMR_RPM_EVEN |
911 UCC_UART_UPSMR_TPM_EVEN;
912 supsmr &= ~(UCC_UART_SUPSMR_RPM_MASK |
913 UCC_UART_SUPSMR_TPM_MASK);
914 supsmr |= UCC_UART_SUPSMR_RPM_EVEN |
915 UCC_UART_SUPSMR_TPM_EVEN;
920 * Set up parity check flag
922 port->read_status_mask = BD_SC_EMPTY | BD_SC_OV;
923 if (termios->c_iflag & INPCK)
924 port->read_status_mask |= BD_SC_FR | BD_SC_PR;
925 if (termios->c_iflag & (BRKINT | PARMRK))
926 port->read_status_mask |= BD_SC_BR;
929 * Characters to ignore
931 port->ignore_status_mask = 0;
932 if (termios->c_iflag & IGNPAR)
933 port->ignore_status_mask |= BD_SC_PR | BD_SC_FR;
934 if (termios->c_iflag & IGNBRK) {
935 port->ignore_status_mask |= BD_SC_BR;
937 * If we're ignore parity and break indicators, ignore
938 * overruns too. (For real raw support).
940 if (termios->c_iflag & IGNPAR)
941 port->ignore_status_mask |= BD_SC_OV;
944 * !!! ignore all characters if CREAD is not set
946 if ((termios->c_cflag & CREAD) == 0)
947 port->read_status_mask &= ~BD_SC_EMPTY;
949 baud = uart_get_baud_rate(port, termios, old, 0, 115200);
951 /* Do we really need a spinlock here? */
952 spin_lock_irqsave(&port->lock, flags);
954 out_be16(&uccp->upsmr, upsmr);
956 out_be16(&uccup->supsmr, supsmr);
957 out_8(&uccup->rx_length, char_length);
959 /* Soft-UART requires a 1X multiplier for TX */
960 qe_setbrg(qe_port->us_info.rx_clock, baud, 16);
961 qe_setbrg(qe_port->us_info.tx_clock, baud, 1);
963 qe_setbrg(qe_port->us_info.rx_clock, baud, 16);
964 qe_setbrg(qe_port->us_info.tx_clock, baud, 16);
967 spin_unlock_irqrestore(&port->lock, flags);
971 * Return a pointer to a string that describes what kind of port this is.
973 static const char *qe_uart_type(struct uart_port *port)
979 * Allocate any memory and I/O resources required by the port.
981 static int qe_uart_request_port(struct uart_port *port)
984 struct uart_qe_port *qe_port =
985 container_of(port, struct uart_qe_port, port);
986 struct ucc_slow_info *us_info = &qe_port->us_info;
987 struct ucc_slow_private *uccs;
988 unsigned int rx_size, tx_size;
990 dma_addr_t bd_dma_addr = 0;
992 ret = ucc_slow_init(us_info, &uccs);
994 dev_err(port->dev, "could not initialize UCC%u\n",
999 qe_port->us_private = uccs;
1000 qe_port->uccp = uccs->us_regs;
1001 qe_port->uccup = (struct ucc_uart_pram *) uccs->us_pram;
1002 qe_port->rx_bd_base = uccs->rx_bd;
1003 qe_port->tx_bd_base = uccs->tx_bd;
1006 * Allocate the transmit and receive data buffers.
1009 rx_size = L1_CACHE_ALIGN(qe_port->rx_nrfifos * qe_port->rx_fifosize);
1010 tx_size = L1_CACHE_ALIGN(qe_port->tx_nrfifos * qe_port->tx_fifosize);
1012 bd_virt = dma_alloc_coherent(port->dev, rx_size + tx_size, &bd_dma_addr,
1015 dev_err(port->dev, "could not allocate buffer descriptors\n");
1019 qe_port->bd_virt = bd_virt;
1020 qe_port->bd_dma_addr = bd_dma_addr;
1021 qe_port->bd_size = rx_size + tx_size;
1023 qe_port->rx_buf = bd_virt;
1024 qe_port->tx_buf = qe_port->rx_buf + rx_size;
1030 * Configure the port.
1032 * We say we're a CPM-type port because that's mostly true. Once the device
1033 * is configured, this driver operates almost identically to the CPM serial
1036 static void qe_uart_config_port(struct uart_port *port, int flags)
1038 if (flags & UART_CONFIG_TYPE) {
1039 port->type = PORT_CPM;
1040 qe_uart_request_port(port);
1045 * Release any memory and I/O resources that were allocated in
1046 * qe_uart_request_port().
1048 static void qe_uart_release_port(struct uart_port *port)
1050 struct uart_qe_port *qe_port =
1051 container_of(port, struct uart_qe_port, port);
1052 struct ucc_slow_private *uccs = qe_port->us_private;
1054 dma_free_coherent(port->dev, qe_port->bd_size, qe_port->bd_virt,
1055 qe_port->bd_dma_addr);
1057 ucc_slow_free(uccs);
1061 * Verify that the data in serial_struct is suitable for this device.
1063 static int qe_uart_verify_port(struct uart_port *port,
1064 struct serial_struct *ser)
1066 if (ser->type != PORT_UNKNOWN && ser->type != PORT_CPM)
1069 if (ser->irq < 0 || ser->irq >= NR_IRQS)
1072 if (ser->baud_base < 9600)
1079 * Details on these functions can be found in Documentation/serial/driver
1081 static struct uart_ops qe_uart_pops = {
1082 .tx_empty = qe_uart_tx_empty,
1083 .set_mctrl = qe_uart_set_mctrl,
1084 .get_mctrl = qe_uart_get_mctrl,
1085 .stop_tx = qe_uart_stop_tx,
1086 .start_tx = qe_uart_start_tx,
1087 .stop_rx = qe_uart_stop_rx,
1088 .enable_ms = qe_uart_enable_ms,
1089 .break_ctl = qe_uart_break_ctl,
1090 .startup = qe_uart_startup,
1091 .shutdown = qe_uart_shutdown,
1092 .set_termios = qe_uart_set_termios,
1093 .type = qe_uart_type,
1094 .release_port = qe_uart_release_port,
1095 .request_port = qe_uart_request_port,
1096 .config_port = qe_uart_config_port,
1097 .verify_port = qe_uart_verify_port,
1101 * Obtain the SOC model number and revision level
1103 * This function parses the device tree to obtain the SOC model. It then
1104 * reads the SVR register to the revision.
1106 * The device tree stores the SOC model two different ways.
1111 * compatible = "PowerPC,8323";
1112 * device_type = "cpu";
1118 * device_type = "cpu";
1121 * This code first checks the new way, and then the old way.
1123 static unsigned int soc_info(unsigned int *rev_h, unsigned int *rev_l)
1125 struct device_node *np;
1126 const char *soc_string;
1130 /* Find the CPU node */
1131 np = of_find_node_by_type(NULL, "cpu");
1134 /* Find the compatible property */
1135 soc_string = of_get_property(np, "compatible", NULL);
1137 /* No compatible property, so try the name. */
1138 soc_string = np->name;
1140 /* Extract the SOC number from the "PowerPC," string */
1141 if ((sscanf(soc_string, "PowerPC,%u", &soc) != 1) || !soc)
1144 /* Get the revision from the SVR */
1145 svr = mfspr(SPRN_SVR);
1146 *rev_h = (svr >> 4) & 0xf;
1153 * requst_firmware_nowait() callback function
1155 * This function is called by the kernel when a firmware is made available,
1156 * or if it times out waiting for the firmware.
1158 static void uart_firmware_cont(const struct firmware *fw, void *context)
1160 struct qe_firmware *firmware;
1161 struct device *dev = context;
1165 dev_err(dev, "firmware not found\n");
1169 firmware = (struct qe_firmware *) fw->data;
1171 if (firmware->header.length != fw->size) {
1172 dev_err(dev, "invalid firmware\n");
1176 ret = qe_upload_firmware(firmware);
1178 dev_err(dev, "could not load firmware\n");
1182 firmware_loaded = 1;
1185 static int ucc_uart_probe(struct of_device *ofdev,
1186 const struct of_device_id *match)
1188 struct device_node *np = ofdev->node;
1189 const unsigned int *iprop; /* Integer OF properties */
1190 const char *sprop; /* String OF properties */
1191 struct uart_qe_port *qe_port = NULL;
1192 struct resource res;
1196 * Determine if we need Soft-UART mode
1198 if (of_find_property(np, "soft-uart", NULL)) {
1199 dev_dbg(&ofdev->dev, "using Soft-UART mode\n");
1204 * If we are using Soft-UART, determine if we need to upload the
1208 struct qe_firmware_info *qe_fw_info;
1210 qe_fw_info = qe_get_firmware_info();
1212 /* Check if the firmware has been uploaded. */
1213 if (qe_fw_info && strstr(qe_fw_info->id, "Soft-UART")) {
1214 firmware_loaded = 1;
1221 soc = soc_info(&rev_h, &rev_l);
1223 dev_err(&ofdev->dev, "unknown CPU model\n");
1226 sprintf(filename, "fsl_qe_ucode_uart_%u_%u%u.bin",
1229 dev_info(&ofdev->dev, "waiting for firmware %s\n",
1233 * We call request_firmware_nowait instead of
1234 * request_firmware so that the driver can load and
1235 * initialize the ports without holding up the rest of
1236 * the kernel. If hotplug support is enabled in the
1237 * kernel, then we use it.
1239 ret = request_firmware_nowait(THIS_MODULE,
1240 FW_ACTION_HOTPLUG, filename, &ofdev->dev,
1241 &ofdev->dev, uart_firmware_cont);
1243 dev_err(&ofdev->dev,
1244 "could not load firmware %s\n",
1251 qe_port = kzalloc(sizeof(struct uart_qe_port), GFP_KERNEL);
1253 dev_err(&ofdev->dev, "can't allocate QE port structure\n");
1257 /* Search for IRQ and mapbase */
1258 ret = of_address_to_resource(np, 0, &res);
1260 dev_err(&ofdev->dev, "missing 'reg' property in device tree\n");
1265 dev_err(&ofdev->dev, "invalid 'reg' property in device tree\n");
1269 qe_port->port.mapbase = res.start;
1271 /* Get the UCC number (device ID) */
1272 /* UCCs are numbered 1-7 */
1273 iprop = of_get_property(np, "cell-index", NULL);
1275 iprop = of_get_property(np, "device-id", NULL);
1277 dev_err(&ofdev->dev, "UCC is unspecified in "
1283 if ((*iprop < 1) || (*iprop > UCC_MAX_NUM)) {
1284 dev_err(&ofdev->dev, "no support for UCC%u\n", *iprop);
1288 qe_port->ucc_num = *iprop - 1;
1291 * In the future, we should not require the BRG to be specified in the
1292 * device tree. If no clock-source is specified, then just pick a BRG
1293 * to use. This requires a new QE library function that manages BRG
1297 sprop = of_get_property(np, "rx-clock-name", NULL);
1299 dev_err(&ofdev->dev, "missing rx-clock-name in device tree\n");
1304 qe_port->us_info.rx_clock = qe_clock_source(sprop);
1305 if ((qe_port->us_info.rx_clock < QE_BRG1) ||
1306 (qe_port->us_info.rx_clock > QE_BRG16)) {
1307 dev_err(&ofdev->dev, "rx-clock-name must be a BRG for UART\n");
1313 /* In internal loopback mode, TX and RX must use the same clock */
1314 qe_port->us_info.tx_clock = qe_port->us_info.rx_clock;
1316 sprop = of_get_property(np, "tx-clock-name", NULL);
1318 dev_err(&ofdev->dev, "missing tx-clock-name in device tree\n");
1322 qe_port->us_info.tx_clock = qe_clock_source(sprop);
1324 if ((qe_port->us_info.tx_clock < QE_BRG1) ||
1325 (qe_port->us_info.tx_clock > QE_BRG16)) {
1326 dev_err(&ofdev->dev, "tx-clock-name must be a BRG for UART\n");
1331 /* Get the port number, numbered 0-3 */
1332 iprop = of_get_property(np, "port-number", NULL);
1334 dev_err(&ofdev->dev, "missing port-number in device tree\n");
1338 qe_port->port.line = *iprop;
1339 if (qe_port->port.line >= UCC_MAX_UART) {
1340 dev_err(&ofdev->dev, "port-number must be 0-%u\n",
1346 qe_port->port.irq = irq_of_parse_and_map(np, 0);
1347 if (qe_port->port.irq == NO_IRQ) {
1348 dev_err(&ofdev->dev, "could not map IRQ for UCC%u\n",
1349 qe_port->ucc_num + 1);
1355 * Newer device trees have an "fsl,qe" compatible property for the QE
1356 * node, but we still need to support older device trees.
1358 np = of_find_compatible_node(NULL, NULL, "fsl,qe");
1360 np = of_find_node_by_type(NULL, "qe");
1362 dev_err(&ofdev->dev, "could not find 'qe' node\n");
1368 iprop = of_get_property(np, "brg-frequency", NULL);
1370 dev_err(&ofdev->dev,
1371 "missing brg-frequency in device tree\n");
1377 qe_port->port.uartclk = *iprop;
1380 * Older versions of U-Boot do not initialize the brg-frequency
1381 * property, so in this case we assume the BRG frequency is
1382 * half the QE bus frequency.
1384 iprop = of_get_property(np, "bus-frequency", NULL);
1386 dev_err(&ofdev->dev,
1387 "missing QE bus-frequency in device tree\n");
1392 qe_port->port.uartclk = *iprop / 2;
1394 dev_err(&ofdev->dev,
1395 "invalid QE bus-frequency in device tree\n");
1401 spin_lock_init(&qe_port->port.lock);
1403 qe_port->port.dev = &ofdev->dev;
1404 qe_port->port.ops = &qe_uart_pops;
1405 qe_port->port.iotype = UPIO_MEM;
1407 qe_port->tx_nrfifos = TX_NUM_FIFO;
1408 qe_port->tx_fifosize = TX_BUF_SIZE;
1409 qe_port->rx_nrfifos = RX_NUM_FIFO;
1410 qe_port->rx_fifosize = RX_BUF_SIZE;
1412 qe_port->wait_closing = UCC_WAIT_CLOSING;
1413 qe_port->port.fifosize = 512;
1414 qe_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
1416 qe_port->us_info.ucc_num = qe_port->ucc_num;
1417 qe_port->us_info.regs = (phys_addr_t) res.start;
1418 qe_port->us_info.irq = qe_port->port.irq;
1420 qe_port->us_info.rx_bd_ring_len = qe_port->rx_nrfifos;
1421 qe_port->us_info.tx_bd_ring_len = qe_port->tx_nrfifos;
1423 /* Make sure ucc_slow_init() initializes both TX and RX */
1424 qe_port->us_info.init_tx = 1;
1425 qe_port->us_info.init_rx = 1;
1427 /* Add the port to the uart sub-system. This will cause
1428 * qe_uart_config_port() to be called, so the us_info structure must
1431 ret = uart_add_one_port(&ucc_uart_driver, &qe_port->port);
1433 dev_err(&ofdev->dev, "could not add /dev/ttyQE%u\n",
1434 qe_port->port.line);
1439 dev_set_drvdata(&ofdev->dev, qe_port);
1441 dev_info(&ofdev->dev, "UCC%u assigned to /dev/ttyQE%u\n",
1442 qe_port->ucc_num + 1, qe_port->port.line);
1444 /* Display the mknod command for this device */
1445 dev_dbg(&ofdev->dev, "mknod command is 'mknod /dev/ttyQE%u c %u %u'\n",
1446 qe_port->port.line, SERIAL_QE_MAJOR,
1447 SERIAL_QE_MINOR + qe_port->port.line);
1452 static int ucc_uart_remove(struct of_device *ofdev)
1454 struct uart_qe_port *qe_port = dev_get_drvdata(&ofdev->dev);
1456 dev_info(&ofdev->dev, "removing /dev/ttyQE%u\n", qe_port->port.line);
1458 uart_remove_one_port(&ucc_uart_driver, &qe_port->port);
1460 dev_set_drvdata(&ofdev->dev, NULL);
1466 static struct of_device_id ucc_uart_match[] = {
1469 .compatible = "ucc_uart",
1473 MODULE_DEVICE_TABLE(of, ucc_uart_match);
1475 static struct of_platform_driver ucc_uart_of_driver = {
1476 .owner = THIS_MODULE,
1478 .match_table = ucc_uart_match,
1479 .probe = ucc_uart_probe,
1480 .remove = ucc_uart_remove,
1483 static int __init ucc_uart_init(void)
1487 printk(KERN_INFO "Freescale QUICC Engine UART device driver\n");
1489 printk(KERN_INFO "ucc-uart: Using loopback mode\n");
1492 ret = uart_register_driver(&ucc_uart_driver);
1494 printk(KERN_ERR "ucc-uart: could not register UART driver\n");
1498 ret = of_register_platform_driver(&ucc_uart_of_driver);
1501 "ucc-uart: could not register platform driver\n");
1506 static void __exit ucc_uart_exit(void)
1509 "Freescale QUICC Engine UART device driver unloading\n");
1511 of_unregister_platform_driver(&ucc_uart_of_driver);
1512 uart_unregister_driver(&ucc_uart_driver);
1515 module_init(ucc_uart_init);
1516 module_exit(ucc_uart_exit);
1518 MODULE_DESCRIPTION("Freescale QUICC Engine (QE) UART");
1519 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
1520 MODULE_LICENSE("GPL v2");
1521 MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_QE_MAJOR);