/* * Freescale QUICC Engine UART device driver * * Author: Timur Tabi <timur@freescale.com> * * Copyright 2007 Freescale Semiconductor, Inc. This file is licensed under * the terms of the GNU General Public License version 2. This program * is licensed "as is" without any warranty of any kind, whether express * or implied. * * This driver adds support for UART devices via Freescale's QUICC Engine * found on some Freescale SOCs. * * If Soft-UART support is needed but not already present, then this driver * will request and upload the "Soft-UART" microcode upon probe. The * filename of the microcode should be fsl_qe_ucode_uart_X_YZ.bin, where "X" * is the name of the SOC (e.g. 8323), and YZ is the revision of the SOC, * (e.g. "11" for 1.1). */ #include <linux/module.h> #include <linux/serial.h> #include <linux/serial_core.h> #include <linux/io.h> #include <linux/of_platform.h> #include <linux/dma-mapping.h> #include <linux/fs_uart_pd.h> #include <asm/ucc_slow.h> #include <linux/firmware.h> #include <asm/reg.h> /* * The GUMR flag for Soft UART. This would normally be defined in qe.h, * but Soft-UART is a hack and we want to keep everything related to it in * this file. */ #define UCC_SLOW_GUMR_H_SUART 0x00004000 /* Soft-UART */ /* * soft_uart is 1 if we need to use Soft-UART mode */ static int soft_uart; /* * firmware_loaded is 1 if the firmware has been loaded, 0 otherwise. */ static int firmware_loaded; /* Enable this macro to configure all serial ports in internal loopback mode */ /* #define LOOPBACK */ /* The major and minor device numbers are defined in * http://www.lanana.org/docs/device-list/devices-2.6+.txt. For the QE * UART, we have major number 204 and minor numbers 46 - 49, which are the * same as for the CPM2. This decision was made because no Freescale part * has both a CPM and a QE. */ #define SERIAL_QE_MAJOR 204 #define SERIAL_QE_MINOR 46 /* Since we only have minor numbers 46 - 49, there is a hard limit of 4 ports */ #define UCC_MAX_UART 4 /* The number of buffer descriptors for receiving characters. */ #define RX_NUM_FIFO 4 /* The number of buffer descriptors for transmitting characters. */ #define TX_NUM_FIFO 4 /* The maximum size of the character buffer for a single RX BD. */ #define RX_BUF_SIZE 32 /* The maximum size of the character buffer for a single TX BD. */ #define TX_BUF_SIZE 32 /* * The number of jiffies to wait after receiving a close command before the * device is actually closed. This allows the last few characters to be * sent over the wire. */ #define UCC_WAIT_CLOSING 100 struct ucc_uart_pram { struct ucc_slow_pram common; u8 res1[8]; /* reserved */ __be16 maxidl; /* Maximum idle chars */ __be16 idlc; /* temp idle counter */ __be16 brkcr; /* Break count register */ __be16 parec; /* receive parity error counter */ __be16 frmec; /* receive framing error counter */ __be16 nosec; /* receive noise counter */ __be16 brkec; /* receive break condition counter */ __be16 brkln; /* last received break length */ __be16 uaddr[2]; /* UART address character 1 & 2 */ __be16 rtemp; /* Temp storage */ __be16 toseq; /* Transmit out of sequence char */ __be16 cchars[8]; /* control characters 1-8 */ __be16 rccm; /* receive control character mask */ __be16 rccr; /* receive control character register */ __be16 rlbc; /* receive last break character */ __be16 res2; /* reserved */ __be32 res3; /* reserved, should be cleared */ u8 res4; /* reserved, should be cleared */ u8 res5[3]; /* reserved, should be cleared */ __be32 res6; /* reserved, should be cleared */ __be32 res7; /* reserved, should be cleared */ __be32 res8; /* reserved, should be cleared */ __be32 res9; /* reserved, should be cleared */ __be32 res10; /* reserved, should be cleared */ __be32 res11; /* reserved, should be cleared */ __be32 res12; /* reserved, should be cleared */ __be32 res13; /* reserved, should be cleared */ /* The rest is for Soft-UART only */ __be16 supsmr; /* 0x90, Shadow UPSMR */ __be16 res92; /* 0x92, reserved, initialize to 0 */ __be32 rx_state; /* 0x94, RX state, initialize to 0 */ __be32 rx_cnt; /* 0x98, RX count, initialize to 0 */ u8 rx_length; /* 0x9C, Char length, set to 1+CL+PEN+1+SL */ u8 rx_bitmark; /* 0x9D, reserved, initialize to 0 */ u8 rx_temp_dlst_qe; /* 0x9E, reserved, initialize to 0 */ u8 res14[0xBC - 0x9F]; /* reserved */ __be32 dump_ptr; /* 0xBC, Dump pointer */ __be32 rx_frame_rem; /* 0xC0, reserved, initialize to 0 */ u8 rx_frame_rem_size; /* 0xC4, reserved, initialize to 0 */ u8 tx_mode; /* 0xC5, mode, 0=AHDLC, 1=UART */ __be16 tx_state; /* 0xC6, TX state */ u8 res15[0xD0 - 0xC8]; /* reserved */ __be32 resD0; /* 0xD0, reserved, initialize to 0 */ u8 resD4; /* 0xD4, reserved, initialize to 0 */ __be16 resD5; /* 0xD5, reserved, initialize to 0 */ } __attribute__ ((packed)); /* SUPSMR definitions, for Soft-UART only */ #define UCC_UART_SUPSMR_SL 0x8000 #define UCC_UART_SUPSMR_RPM_MASK 0x6000 #define UCC_UART_SUPSMR_RPM_ODD 0x0000 #define UCC_UART_SUPSMR_RPM_LOW 0x2000 #define UCC_UART_SUPSMR_RPM_EVEN 0x4000 #define UCC_UART_SUPSMR_RPM_HIGH 0x6000 #define UCC_UART_SUPSMR_PEN 0x1000 #define UCC_UART_SUPSMR_TPM_MASK 0x0C00 #define UCC_UART_SUPSMR_TPM_ODD 0x0000 #define UCC_UART_SUPSMR_TPM_LOW 0x0400 #define UCC_UART_SUPSMR_TPM_EVEN 0x0800 #define UCC_UART_SUPSMR_TPM_HIGH 0x0C00 #define UCC_UART_SUPSMR_FRZ 0x0100 #define UCC_UART_SUPSMR_UM_MASK 0x00c0 #define UCC_UART_SUPSMR_UM_NORMAL 0x0000 #define UCC_UART_SUPSMR_UM_MAN_MULTI 0x0040 #define UCC_UART_SUPSMR_UM_AUTO_MULTI 0x00c0 #define UCC_UART_SUPSMR_CL_MASK 0x0030 #define UCC_UART_SUPSMR_CL_8 0x0030 #define UCC_UART_SUPSMR_CL_7 0x0020 #define UCC_UART_SUPSMR_CL_6 0x0010 #define UCC_UART_SUPSMR_CL_5 0x0000 #define UCC_UART_TX_STATE_AHDLC 0x00 #define UCC_UART_TX_STATE_UART 0x01 #define UCC_UART_TX_STATE_X1 0x00 #define UCC_UART_TX_STATE_X16 0x80 #define UCC_UART_PRAM_ALIGNMENT 0x100 #define UCC_UART_SIZE_OF_BD UCC_SLOW_SIZE_OF_BD #define NUM_CONTROL_CHARS 8 /* Private per-port data structure */ struct uart_qe_port { struct uart_port port; struct ucc_slow __iomem *uccp; struct ucc_uart_pram __iomem *uccup; struct ucc_slow_info us_info; struct ucc_slow_private *us_private; struct device_node *np; unsigned int ucc_num; /* First ucc is 0, not 1 */ u16 rx_nrfifos; u16 rx_fifosize; u16 tx_nrfifos; u16 tx_fifosize; int wait_closing; u32 flags; struct qe_bd *rx_bd_base; struct qe_bd *rx_cur; struct qe_bd *tx_bd_base; struct qe_bd *tx_cur; unsigned char *tx_buf; unsigned char *rx_buf; void *bd_virt; /* virtual address of the BD buffers */ dma_addr_t bd_dma_addr; /* bus address of the BD buffers */ unsigned int bd_size; /* size of BD buffer space */ }; static struct uart_driver ucc_uart_driver = { .owner = THIS_MODULE, .driver_name = "serial", .dev_name = "ttyQE", .major = SERIAL_QE_MAJOR, .minor = SERIAL_QE_MINOR, .nr = UCC_MAX_UART, }; /* * Virtual to physical address translation. * * Given the virtual address for a character buffer, this function returns * the physical (DMA) equivalent. */ static inline dma_addr_t cpu2qe_addr(void *addr, struct uart_qe_port *qe_port) { if (likely((addr >= qe_port->bd_virt)) && (addr < (qe_port->bd_virt + qe_port->bd_size))) return qe_port->bd_dma_addr + (addr - qe_port->bd_virt); /* something nasty happened */ printk(KERN_ERR "%s: addr=%p\n", __FUNCTION__, addr); BUG(); return 0; } /* * Physical to virtual address translation. * * Given the physical (DMA) address for a character buffer, this function * returns the virtual equivalent. */ static inline void *qe2cpu_addr(dma_addr_t addr, struct uart_qe_port *qe_port) { /* sanity check */ if (likely((addr >= qe_port->bd_dma_addr) && (addr < (qe_port->bd_dma_addr + qe_port->bd_size)))) return qe_port->bd_virt + (addr - qe_port->bd_dma_addr); /* something nasty happened */ printk(KERN_ERR "%s: addr=%x\n", __FUNCTION__, addr); BUG(); return NULL; } /* * Return 1 if the QE is done transmitting all buffers for this port * * This function scans each BD in sequence. If we find a BD that is not * ready (READY=1), then we return 0 indicating that the QE is still sending * data. If we reach the last BD (WRAP=1), then we know we've scanned * the entire list, and all BDs are done. */ static unsigned int qe_uart_tx_empty(struct uart_port *port) { struct uart_qe_port *qe_port = container_of(port, struct uart_qe_port, port); struct qe_bd *bdp = qe_port->tx_bd_base; while (1) { if (in_be16(&bdp->status) & BD_SC_READY) /* This BD is not done, so return "not done" */ return 0; if (in_be16(&bdp->status) & BD_SC_WRAP) /* * This BD is done and it's the last one, so return * "done" */ return 1; bdp++; }; } /* * Set the modem control lines * * Although the QE can control the modem control lines (e.g. CTS), we * don't need that support. This function must exist, however, otherwise * the kernel will panic. */ void qe_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) { } /* * Get the current modem control line status * * Although the QE can control the modem control lines (e.g. CTS), this * driver currently doesn't support that, so we always return Carrier * Detect, Data Set Ready, and Clear To Send. */ static unsigned int qe_uart_get_mctrl(struct uart_port *port) { return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; } /* * Disable the transmit interrupt. * * Although this function is called "stop_tx", it does not actually stop * transmission of data. Instead, it tells the QE to not generate an * interrupt when the UCC is finished sending characters. */ static void qe_uart_stop_tx(struct uart_port *port) { struct uart_qe_port *qe_port = container_of(port, struct uart_qe_port, port); clrbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_TX); } /* * Transmit as many characters to the HW as possible. * * This function will attempt to stuff of all the characters from the * kernel's transmit buffer into TX BDs. * * A return value of non-zero indicates that it sucessfully stuffed all * characters from the kernel buffer. * * A return value of zero indicates that there are still characters in the * kernel's buffer that have not been transmitted, but there are no more BDs * available. This function should be called again after a BD has been made * available. */ static int qe_uart_tx_pump(struct uart_qe_port *qe_port) { struct qe_bd *bdp; unsigned char *p; unsigned int count; struct uart_port *port = &qe_port->port; struct circ_buf *xmit = &port->info->xmit; bdp = qe_port->rx_cur; /* Handle xon/xoff */ if (port->x_char) { /* Pick next descriptor and fill from buffer */ bdp = qe_port->tx_cur; p = qe2cpu_addr(bdp->buf, qe_port); *p++ = port->x_char; out_be16(&bdp->length, 1); setbits16(&bdp->status, BD_SC_READY); /* Get next BD. */ if (in_be16(&bdp->status) & BD_SC_WRAP) bdp = qe_port->tx_bd_base; else bdp++; qe_port->tx_cur = bdp; port->icount.tx++; port->x_char = 0; return 1; } if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { qe_uart_stop_tx(port); return 0; } /* Pick next descriptor and fill from buffer */ bdp = qe_port->tx_cur; while (!(in_be16(&bdp->status) & BD_SC_READY) && (xmit->tail != xmit->head)) { count = 0; p = qe2cpu_addr(bdp->buf, qe_port); while (count < qe_port->tx_fifosize) { *p++ = xmit->buf[xmit->tail]; xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; count++; if (xmit->head == xmit->tail) break; } out_be16(&bdp->length, count); setbits16(&bdp->status, BD_SC_READY); /* Get next BD. */ if (in_be16(&bdp->status) & BD_SC_WRAP) bdp = qe_port->tx_bd_base; else bdp++; } qe_port->tx_cur = bdp; if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); if (uart_circ_empty(xmit)) { /* The kernel buffer is empty, so turn off TX interrupts. We don't need to be told when the QE is finished transmitting the data. */ qe_uart_stop_tx(port); return 0; } return 1; } /* * Start transmitting data * * This function will start transmitting any available data, if the port * isn't already transmitting data. */ static void qe_uart_start_tx(struct uart_port *port) { struct uart_qe_port *qe_port = container_of(port, struct uart_qe_port, port); /* If we currently are transmitting, then just return */ if (in_be16(&qe_port->uccp->uccm) & UCC_UART_UCCE_TX) return; /* Otherwise, pump the port and start transmission */ if (qe_uart_tx_pump(qe_port)) setbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_TX); } /* * Stop transmitting data */ static void qe_uart_stop_rx(struct uart_port *port) { struct uart_qe_port *qe_port = container_of(port, struct uart_qe_port, port); clrbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_RX); } /* * Enable status change interrupts * * We don't support status change interrupts, but we need to define this * function otherwise the kernel will panic. */ static void qe_uart_enable_ms(struct uart_port *port) { } /* Start or stop sending break signal * * This function controls the sending of a break signal. If break_state=1, * then we start sending a break signal. If break_state=0, then we stop * sending the break signal. */ static void qe_uart_break_ctl(struct uart_port *port, int break_state) { struct uart_qe_port *qe_port = container_of(port, struct uart_qe_port, port); if (break_state) ucc_slow_stop_tx(qe_port->us_private); else ucc_slow_restart_tx(qe_port->us_private); } /* ISR helper function for receiving character. * * This function is called by the ISR to handling receiving characters */ static void qe_uart_int_rx(struct uart_qe_port *qe_port) { int i; unsigned char ch, *cp; struct uart_port *port = &qe_port->port; struct tty_struct *tty = port->info->tty; struct qe_bd *bdp; u16 status; unsigned int flg; /* Just loop through the closed BDs and copy the characters into * the buffer. */ bdp = qe_port->rx_cur; while (1) { status = in_be16(&bdp->status); /* If this one is empty, then we assume we've read them all */ if (status & BD_SC_EMPTY) break; /* get number of characters, and check space in RX buffer */ i = in_be16(&bdp->length); /* If we don't have enough room in RX buffer for the entire BD, * then we try later, which will be the next RX interrupt. */ if (tty_buffer_request_room(tty, i) < i) { dev_dbg(port->dev, "ucc-uart: no room in RX buffer\n"); return; } /* get pointer */ cp = qe2cpu_addr(bdp->buf, qe_port); /* loop through the buffer */ while (i-- > 0) { ch = *cp++; port->icount.rx++; flg = TTY_NORMAL; if (!i && status & (BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV)) goto handle_error; if (uart_handle_sysrq_char(port, ch)) continue; error_return: tty_insert_flip_char(tty, ch, flg); } /* This BD is ready to be used again. Clear status. get next */ clrsetbits_be16(&bdp->status, BD_SC_BR | BD_SC_FR | BD_SC_PR | BD_SC_OV | BD_SC_ID, BD_SC_EMPTY); if (in_be16(&bdp->status) & BD_SC_WRAP) bdp = qe_port->rx_bd_base; else bdp++; } /* Write back buffer pointer */ qe_port->rx_cur = bdp; /* Activate BH processing */ tty_flip_buffer_push(tty); return; /* Error processing */ handle_error: /* Statistics */ if (status & BD_SC_BR) port->icount.brk++; if (status & BD_SC_PR) port->icount.parity++; if (status & BD_SC_FR) port->icount.frame++; if (status & BD_SC_OV) port->icount.overrun++; /* Mask out ignored conditions */ status &= port->read_status_mask; /* Handle the remaining ones */ if (status & BD_SC_BR) flg = TTY_BREAK; else if (status & BD_SC_PR) flg = TTY_PARITY; else if (status & BD_SC_FR) flg = TTY_FRAME; /* Overrun does not affect the current character ! */ if (status & BD_SC_OV) tty_insert_flip_char(tty, 0, TTY_OVERRUN); #ifdef SUPPORT_SYSRQ port->sysrq = 0; #endif goto error_return; } /* Interrupt handler * * This interrupt handler is called after a BD is processed. */ static irqreturn_t qe_uart_int(int irq, void *data) { struct uart_qe_port *qe_port = (struct uart_qe_port *) data; struct ucc_slow __iomem *uccp = qe_port->uccp; u16 events; /* Clear the interrupts */ events = in_be16(&uccp->ucce); out_be16(&uccp->ucce, events); if (events & UCC_UART_UCCE_BRKE) uart_handle_break(&qe_port->port); if (events & UCC_UART_UCCE_RX) qe_uart_int_rx(qe_port); if (events & UCC_UART_UCCE_TX) qe_uart_tx_pump(qe_port); return events ? IRQ_HANDLED : IRQ_NONE; } /* Initialize buffer descriptors * * This function initializes all of the RX and TX buffer descriptors. */ static void qe_uart_initbd(struct uart_qe_port *qe_port) { int i; void *bd_virt; struct qe_bd *bdp; /* Set the physical address of the host memory buffers in the buffer * descriptors, and the virtual address for us to work with. */ bd_virt = qe_port->bd_virt; bdp = qe_port->rx_bd_base; qe_port->rx_cur = qe_port->rx_bd_base; for (i = 0; i < (qe_port->rx_nrfifos - 1); i++) { out_be16(&bdp->status, BD_SC_EMPTY | BD_SC_INTRPT); out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port)); out_be16(&bdp->length, 0); bd_virt += qe_port->rx_fifosize; bdp++; } /* */ out_be16(&bdp->status, BD_SC_WRAP | BD_SC_EMPTY | BD_SC_INTRPT); out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port)); out_be16(&bdp->length, 0); /* Set the physical address of the host memory * buffers in the buffer descriptors, and the * virtual address for us to work with. */ bd_virt = qe_port->bd_virt + L1_CACHE_ALIGN(qe_port->rx_nrfifos * qe_port->rx_fifosize); qe_port->tx_cur = qe_port->tx_bd_base; bdp = qe_port->tx_bd_base; for (i = 0; i < (qe_port->tx_nrfifos - 1); i++) { out_be16(&bdp->status, BD_SC_INTRPT); out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port)); out_be16(&bdp->length, 0); bd_virt += qe_port->tx_fifosize; bdp++; } /* Loopback requires the preamble bit to be set on the first TX BD */ #ifdef LOOPBACK setbits16(&qe_port->tx_cur->status, BD_SC_P); #endif out_be16(&bdp->status, BD_SC_WRAP | BD_SC_INTRPT); out_be32(&bdp->buf, cpu2qe_addr(bd_virt, qe_port)); out_be16(&bdp->length, 0); } /* * Initialize a UCC for UART. * * This function configures a given UCC to be used as a UART device. Basic * UCC initialization is handled in qe_uart_request_port(). This function * does all the UART-specific stuff. */ static void qe_uart_init_ucc(struct uart_qe_port *qe_port) { u32 cecr_subblock; struct ucc_slow __iomem *uccp = qe_port->uccp; struct ucc_uart_pram *uccup = qe_port->uccup; unsigned int i; /* First, disable TX and RX in the UCC */ ucc_slow_disable(qe_port->us_private, COMM_DIR_RX_AND_TX); /* Program the UCC UART parameter RAM */ out_8(&uccup->common.rbmr, UCC_BMR_GBL | UCC_BMR_BO_BE); out_8(&uccup->common.tbmr, UCC_BMR_GBL | UCC_BMR_BO_BE); out_be16(&uccup->common.mrblr, qe_port->rx_fifosize); out_be16(&uccup->maxidl, 0x10); out_be16(&uccup->brkcr, 1); out_be16(&uccup->parec, 0); out_be16(&uccup->frmec, 0); out_be16(&uccup->nosec, 0); out_be16(&uccup->brkec, 0); out_be16(&uccup->uaddr[0], 0); out_be16(&uccup->uaddr[1], 0); out_be16(&uccup->toseq, 0); for (i = 0; i < 8; i++) out_be16(&uccup->cchars[i], 0xC000); out_be16(&uccup->rccm, 0xc0ff); /* Configure the GUMR registers for UART */ if (soft_uart) /* Soft-UART requires a 1X multiplier for TX */ clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK | UCC_SLOW_GUMR_L_RDCR_MASK, UCC_SLOW_GUMR_L_MODE_UART | UCC_SLOW_GUMR_L_TDCR_1 | UCC_SLOW_GUMR_L_RDCR_16); else clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK | UCC_SLOW_GUMR_L_RDCR_MASK, UCC_SLOW_GUMR_L_MODE_UART | UCC_SLOW_GUMR_L_TDCR_16 | UCC_SLOW_GUMR_L_RDCR_16); clrsetbits_be32(&uccp->gumr_h, UCC_SLOW_GUMR_H_RFW, UCC_SLOW_GUMR_H_TRX | UCC_SLOW_GUMR_H_TTX); #ifdef LOOPBACK clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_DIAG_MASK, UCC_SLOW_GUMR_L_DIAG_LOOP); clrsetbits_be32(&uccp->gumr_h, UCC_SLOW_GUMR_H_CTSP | UCC_SLOW_GUMR_H_RSYN, UCC_SLOW_GUMR_H_CDS); #endif /* Enable rx interrupts and clear all pending events. */ out_be16(&uccp->uccm, 0); out_be16(&uccp->ucce, 0xffff); out_be16(&uccp->udsr, 0x7e7e); /* Initialize UPSMR */ out_be16(&uccp->upsmr, 0); if (soft_uart) { out_be16(&uccup->supsmr, 0x30); out_be16(&uccup->res92, 0); out_be32(&uccup->rx_state, 0); out_be32(&uccup->rx_cnt, 0); out_8(&uccup->rx_bitmark, 0); out_8(&uccup->rx_length, 10); out_be32(&uccup->dump_ptr, 0x4000); out_8(&uccup->rx_temp_dlst_qe, 0); out_be32(&uccup->rx_frame_rem, 0); out_8(&uccup->rx_frame_rem_size, 0); /* Soft-UART requires TX to be 1X */ out_8(&uccup->tx_mode, UCC_UART_TX_STATE_UART | UCC_UART_TX_STATE_X1); out_be16(&uccup->tx_state, 0); out_8(&uccup->resD4, 0); out_be16(&uccup->resD5, 0); /* Set UART mode. * Enable receive and transmit. */ /* From the microcode errata: * 1.GUMR_L register, set mode=0010 (QMC). * 2.Set GUMR_H[17] bit. (UART/AHDLC mode). * 3.Set GUMR_H[19:20] (Transparent mode) * 4.Clear GUMR_H[26] (RFW) * ... * 6.Receiver must use 16x over sampling */ clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_MODE_MASK | UCC_SLOW_GUMR_L_TDCR_MASK | UCC_SLOW_GUMR_L_RDCR_MASK, UCC_SLOW_GUMR_L_MODE_QMC | UCC_SLOW_GUMR_L_TDCR_16 | UCC_SLOW_GUMR_L_RDCR_16); clrsetbits_be32(&uccp->gumr_h, UCC_SLOW_GUMR_H_RFW | UCC_SLOW_GUMR_H_RSYN, UCC_SLOW_GUMR_H_SUART | UCC_SLOW_GUMR_H_TRX | UCC_SLOW_GUMR_H_TTX | UCC_SLOW_GUMR_H_TFL); #ifdef LOOPBACK clrsetbits_be32(&uccp->gumr_l, UCC_SLOW_GUMR_L_DIAG_MASK, UCC_SLOW_GUMR_L_DIAG_LOOP); clrbits32(&uccp->gumr_h, UCC_SLOW_GUMR_H_CTSP | UCC_SLOW_GUMR_H_CDS); #endif cecr_subblock = ucc_slow_get_qe_cr_subblock(qe_port->ucc_num); qe_issue_cmd(QE_INIT_TX_RX, cecr_subblock, QE_CR_PROTOCOL_UNSPECIFIED, 0); } } /* * Initialize the port. */ static int qe_uart_startup(struct uart_port *port) { struct uart_qe_port *qe_port = container_of(port, struct uart_qe_port, port); int ret; /* * If we're using Soft-UART mode, then we need to make sure the * firmware has been uploaded first. */ if (soft_uart && !firmware_loaded) { dev_err(port->dev, "Soft-UART firmware not uploaded\n"); return -ENODEV; } qe_uart_initbd(qe_port); qe_uart_init_ucc(qe_port); /* Install interrupt handler. */ ret = request_irq(port->irq, qe_uart_int, IRQF_SHARED, "ucc-uart", qe_port); if (ret) { dev_err(port->dev, "could not claim IRQ %u\n", port->irq); return ret; } /* Startup rx-int */ setbits16(&qe_port->uccp->uccm, UCC_UART_UCCE_RX); ucc_slow_enable(qe_port->us_private, COMM_DIR_RX_AND_TX); return 0; } /* * Shutdown the port. */ static void qe_uart_shutdown(struct uart_port *port) { struct uart_qe_port *qe_port = container_of(port, struct uart_qe_port, port); struct ucc_slow __iomem *uccp = qe_port->uccp; unsigned int timeout = 20; /* Disable RX and TX */ /* Wait for all the BDs marked sent */ while (!qe_uart_tx_empty(port)) { if (!--timeout) { dev_warn(port->dev, "shutdown timeout\n"); break; } set_current_state(TASK_UNINTERRUPTIBLE); schedule_timeout(2); } if (qe_port->wait_closing) { /* Wait a bit longer */ set_current_state(TASK_UNINTERRUPTIBLE); schedule_timeout(qe_port->wait_closing); } /* Stop uarts */ ucc_slow_disable(qe_port->us_private, COMM_DIR_RX_AND_TX); clrbits16(&uccp->uccm, UCC_UART_UCCE_TX | UCC_UART_UCCE_RX); /* Shut them really down and reinit buffer descriptors */ ucc_slow_graceful_stop_tx(qe_port->us_private); qe_uart_initbd(qe_port); free_irq(port->irq, qe_port); } /* * Set the serial port parameters. */ static void qe_uart_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct uart_qe_port *qe_port = container_of(port, struct uart_qe_port, port); struct ucc_slow __iomem *uccp = qe_port->uccp; unsigned int baud; unsigned long flags; u16 upsmr = in_be16(&uccp->upsmr); struct ucc_uart_pram __iomem *uccup = qe_port->uccup; u16 supsmr = in_be16(&uccup->supsmr); u8 char_length = 2; /* 1 + CL + PEN + 1 + SL */ /* Character length programmed into the mode register is the * sum of: 1 start bit, number of data bits, 0 or 1 parity bit, * 1 or 2 stop bits, minus 1. * The value 'bits' counts this for us. */ /* byte size */ upsmr &= UCC_UART_UPSMR_CL_MASK; supsmr &= UCC_UART_SUPSMR_CL_MASK; switch (termios->c_cflag & CSIZE) { case CS5: upsmr |= UCC_UART_UPSMR_CL_5; supsmr |= UCC_UART_SUPSMR_CL_5; char_length += 5; break; case CS6: upsmr |= UCC_UART_UPSMR_CL_6; supsmr |= UCC_UART_SUPSMR_CL_6; char_length += 6; break; case CS7: upsmr |= UCC_UART_UPSMR_CL_7; supsmr |= UCC_UART_SUPSMR_CL_7; char_length += 7; break; default: /* case CS8 */ upsmr |= UCC_UART_UPSMR_CL_8; supsmr |= UCC_UART_SUPSMR_CL_8; char_length += 8; break; } /* If CSTOPB is set, we want two stop bits */ if (termios->c_cflag & CSTOPB) { upsmr |= UCC_UART_UPSMR_SL; supsmr |= UCC_UART_SUPSMR_SL; char_length++; /* + SL */ } if (termios->c_cflag & PARENB) { upsmr |= UCC_UART_UPSMR_PEN; supsmr |= UCC_UART_SUPSMR_PEN; char_length++; /* + PEN */ if (!(termios->c_cflag & PARODD)) { upsmr &= ~(UCC_UART_UPSMR_RPM_MASK | UCC_UART_UPSMR_TPM_MASK); upsmr |= UCC_UART_UPSMR_RPM_EVEN | UCC_UART_UPSMR_TPM_EVEN; supsmr &= ~(UCC_UART_SUPSMR_RPM_MASK | UCC_UART_SUPSMR_TPM_MASK); supsmr |= UCC_UART_SUPSMR_RPM_EVEN | UCC_UART_SUPSMR_TPM_EVEN; } } /* * Set up parity check flag */ port->read_status_mask = BD_SC_EMPTY | BD_SC_OV; if (termios->c_iflag & INPCK) port->read_status_mask |= BD_SC_FR | BD_SC_PR; if (termios->c_iflag & (BRKINT | PARMRK)) port->read_status_mask |= BD_SC_BR; /* * Characters to ignore */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= BD_SC_PR | BD_SC_FR; if (termios->c_iflag & IGNBRK) { port->ignore_status_mask |= BD_SC_BR; /* * If we're ignore parity and break indicators, ignore * overruns too. (For real raw support). */ if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= BD_SC_OV; } /* * !!! ignore all characters if CREAD is not set */ if ((termios->c_cflag & CREAD) == 0) port->read_status_mask &= ~BD_SC_EMPTY; baud = uart_get_baud_rate(port, termios, old, 0, 115200); /* Do we really need a spinlock here? */ spin_lock_irqsave(&port->lock, flags); out_be16(&uccp->upsmr, upsmr); if (soft_uart) { out_be16(&uccup->supsmr, supsmr); out_8(&uccup->rx_length, char_length); /* Soft-UART requires a 1X multiplier for TX */ qe_setbrg(qe_port->us_info.rx_clock, baud, 16); qe_setbrg(qe_port->us_info.tx_clock, baud, 1); } else { qe_setbrg(qe_port->us_info.rx_clock, baud, 16); qe_setbrg(qe_port->us_info.tx_clock, baud, 16); } spin_unlock_irqrestore(&port->lock, flags); } /* * Return a pointer to a string that describes what kind of port this is. */ static const char *qe_uart_type(struct uart_port *port) { return "QE"; } /* * Allocate any memory and I/O resources required by the port. */ static int qe_uart_request_port(struct uart_port *port) { int ret; struct uart_qe_port *qe_port = container_of(port, struct uart_qe_port, port); struct ucc_slow_info *us_info = &qe_port->us_info; struct ucc_slow_private *uccs; unsigned int rx_size, tx_size; void *bd_virt; dma_addr_t bd_dma_addr = 0; ret = ucc_slow_init(us_info, &uccs); if (ret) { dev_err(port->dev, "could not initialize UCC%u\n", qe_port->ucc_num); return ret; } qe_port->us_private = uccs; qe_port->uccp = uccs->us_regs; qe_port->uccup = (struct ucc_uart_pram *) uccs->us_pram; qe_port->rx_bd_base = uccs->rx_bd; qe_port->tx_bd_base = uccs->tx_bd; /* * Allocate the transmit and receive data buffers. */ rx_size = L1_CACHE_ALIGN(qe_port->rx_nrfifos * qe_port->rx_fifosize); tx_size = L1_CACHE_ALIGN(qe_port->tx_nrfifos * qe_port->tx_fifosize); bd_virt = dma_alloc_coherent(NULL, rx_size + tx_size, &bd_dma_addr, GFP_KERNEL); if (!bd_virt) { dev_err(port->dev, "could not allocate buffer descriptors\n"); return -ENOMEM; } qe_port->bd_virt = bd_virt; qe_port->bd_dma_addr = bd_dma_addr; qe_port->bd_size = rx_size + tx_size; qe_port->rx_buf = bd_virt; qe_port->tx_buf = qe_port->rx_buf + rx_size; return 0; } /* * Configure the port. * * We say we're a CPM-type port because that's mostly true. Once the device * is configured, this driver operates almost identically to the CPM serial * driver. */ static void qe_uart_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) { port->type = PORT_CPM; qe_uart_request_port(port); } } /* * Release any memory and I/O resources that were allocated in * qe_uart_request_port(). */ static void qe_uart_release_port(struct uart_port *port) { struct uart_qe_port *qe_port = container_of(port, struct uart_qe_port, port); struct ucc_slow_private *uccs = qe_port->us_private; dma_free_coherent(NULL, qe_port->bd_size, qe_port->bd_virt, qe_port->bd_dma_addr); ucc_slow_free(uccs); } /* * Verify that the data in serial_struct is suitable for this device. */ static int qe_uart_verify_port(struct uart_port *port, struct serial_struct *ser) { if (ser->type != PORT_UNKNOWN && ser->type != PORT_CPM) return -EINVAL; if (ser->irq < 0 || ser->irq >= NR_IRQS) return -EINVAL; if (ser->baud_base < 9600) return -EINVAL; return 0; } /* UART operations * * Details on these functions can be found in Documentation/serial/driver */ static struct uart_ops qe_uart_pops = { .tx_empty = qe_uart_tx_empty, .set_mctrl = qe_uart_set_mctrl, .get_mctrl = qe_uart_get_mctrl, .stop_tx = qe_uart_stop_tx, .start_tx = qe_uart_start_tx, .stop_rx = qe_uart_stop_rx, .enable_ms = qe_uart_enable_ms, .break_ctl = qe_uart_break_ctl, .startup = qe_uart_startup, .shutdown = qe_uart_shutdown, .set_termios = qe_uart_set_termios, .type = qe_uart_type, .release_port = qe_uart_release_port, .request_port = qe_uart_request_port, .config_port = qe_uart_config_port, .verify_port = qe_uart_verify_port, }; /* * Obtain the SOC model number and revision level * * This function parses the device tree to obtain the SOC model. It then * reads the SVR register to the revision. * * The device tree stores the SOC model two different ways. * * The new way is: * * cpu@0 { * compatible = "PowerPC,8323"; * device_type = "cpu"; * ... * * * The old way is: * PowerPC,8323@0 { * device_type = "cpu"; * ... * * This code first checks the new way, and then the old way. */ static unsigned int soc_info(unsigned int *rev_h, unsigned int *rev_l) { struct device_node *np; const char *soc_string; unsigned int svr; unsigned int soc; /* Find the CPU node */ np = of_find_node_by_type(NULL, "cpu"); if (!np) return 0; /* Find the compatible property */ soc_string = of_get_property(np, "compatible", NULL); if (!soc_string) /* No compatible property, so try the name. */ soc_string = np->name; /* Extract the SOC number from the "PowerPC," string */ if ((sscanf(soc_string, "PowerPC,%u", &soc) != 1) || !soc) return 0; /* Get the revision from the SVR */ svr = mfspr(SPRN_SVR); *rev_h = (svr >> 4) & 0xf; *rev_l = svr & 0xf; return soc; } /* * requst_firmware_nowait() callback function * * This function is called by the kernel when a firmware is made available, * or if it times out waiting for the firmware. */ static void uart_firmware_cont(const struct firmware *fw, void *context) { struct qe_firmware *firmware; struct device *dev = context; int ret; if (!fw) { dev_err(dev, "firmware not found\n"); return; } firmware = (struct qe_firmware *) fw->data; if (firmware->header.length != fw->size) { dev_err(dev, "invalid firmware\n"); return; } ret = qe_upload_firmware(firmware); if (ret) { dev_err(dev, "could not load firmware\n"); return; } firmware_loaded = 1; } static int ucc_uart_probe(struct of_device *ofdev, const struct of_device_id *match) { struct device_node *np = ofdev->node; const unsigned int *iprop; /* Integer OF properties */ const char *sprop; /* String OF properties */ struct uart_qe_port *qe_port = NULL; struct resource res; int ret; /* * Determine if we need Soft-UART mode */ if (of_find_property(np, "soft-uart", NULL)) { dev_dbg(&ofdev->dev, "using Soft-UART mode\n"); soft_uart = 1; } /* * If we are using Soft-UART, determine if we need to upload the * firmware, too. */ if (soft_uart) { struct qe_firmware_info *qe_fw_info; qe_fw_info = qe_get_firmware_info(); /* Check if the firmware has been uploaded. */ if (qe_fw_info && strstr(qe_fw_info->id, "Soft-UART")) { firmware_loaded = 1; } else { char filename[32]; unsigned int soc; unsigned int rev_h; unsigned int rev_l; soc = soc_info(&rev_h, &rev_l); if (!soc) { dev_err(&ofdev->dev, "unknown CPU model\n"); return -ENXIO; } sprintf(filename, "fsl_qe_ucode_uart_%u_%u%u.bin", soc, rev_h, rev_l); dev_info(&ofdev->dev, "waiting for firmware %s\n", filename); /* * We call request_firmware_nowait instead of * request_firmware so that the driver can load and * initialize the ports without holding up the rest of * the kernel. If hotplug support is enabled in the * kernel, then we use it. */ ret = request_firmware_nowait(THIS_MODULE, FW_ACTION_HOTPLUG, filename, &ofdev->dev, &ofdev->dev, uart_firmware_cont); if (ret) { dev_err(&ofdev->dev, "could not load firmware %s\n", filename); return ret; } } } qe_port = kzalloc(sizeof(struct uart_qe_port), GFP_KERNEL); if (!qe_port) { dev_err(&ofdev->dev, "can't allocate QE port structure\n"); return -ENOMEM; } /* Search for IRQ and mapbase */ ret = of_address_to_resource(np, 0, &res); if (ret) { dev_err(&ofdev->dev, "missing 'reg' property in device tree\n"); kfree(qe_port); return ret; } if (!res.start) { dev_err(&ofdev->dev, "invalid 'reg' property in device tree\n"); kfree(qe_port); return -EINVAL; } qe_port->port.mapbase = res.start; /* Get the UCC number (device ID) */ /* UCCs are numbered 1-7 */ iprop = of_get_property(np, "cell-index", NULL); if (!iprop) { iprop = of_get_property(np, "device-id", NULL); if (!iprop) { dev_err(&ofdev->dev, "UCC is unspecified in " "device tree\n"); return -EINVAL; } } if ((*iprop < 1) || (*iprop > UCC_MAX_NUM)) { dev_err(&ofdev->dev, "no support for UCC%u\n", *iprop); kfree(qe_port); return -ENODEV; } qe_port->ucc_num = *iprop - 1; /* * In the future, we should not require the BRG to be specified in the * device tree. If no clock-source is specified, then just pick a BRG * to use. This requires a new QE library function that manages BRG * assignments. */ sprop = of_get_property(np, "rx-clock-name", NULL); if (!sprop) { dev_err(&ofdev->dev, "missing rx-clock-name in device tree\n"); kfree(qe_port); return -ENODEV; } qe_port->us_info.rx_clock = qe_clock_source(sprop); if ((qe_port->us_info.rx_clock < QE_BRG1) || (qe_port->us_info.rx_clock > QE_BRG16)) { dev_err(&ofdev->dev, "rx-clock-name must be a BRG for UART\n"); kfree(qe_port); return -ENODEV; } #ifdef LOOPBACK /* In internal loopback mode, TX and RX must use the same clock */ qe_port->us_info.tx_clock = qe_port->us_info.rx_clock; #else sprop = of_get_property(np, "tx-clock-name", NULL); if (!sprop) { dev_err(&ofdev->dev, "missing tx-clock-name in device tree\n"); kfree(qe_port); return -ENODEV; } qe_port->us_info.tx_clock = qe_clock_source(sprop); #endif if ((qe_port->us_info.tx_clock < QE_BRG1) || (qe_port->us_info.tx_clock > QE_BRG16)) { dev_err(&ofdev->dev, "tx-clock-name must be a BRG for UART\n"); kfree(qe_port); return -ENODEV; } /* Get the port number, numbered 0-3 */ iprop = of_get_property(np, "port-number", NULL); if (!iprop) { dev_err(&ofdev->dev, "missing port-number in device tree\n"); kfree(qe_port); return -EINVAL; } qe_port->port.line = *iprop; if (qe_port->port.line >= UCC_MAX_UART) { dev_err(&ofdev->dev, "port-number must be 0-%u\n", UCC_MAX_UART - 1); kfree(qe_port); return -EINVAL; } qe_port->port.irq = irq_of_parse_and_map(np, 0); if (qe_port->port.irq == NO_IRQ) { dev_err(&ofdev->dev, "could not map IRQ for UCC%u\n", qe_port->ucc_num + 1); kfree(qe_port); return -EINVAL; } /* * Newer device trees have an "fsl,qe" compatible property for the QE * node, but we still need to support older device trees. */ np = of_find_compatible_node(NULL, NULL, "fsl,qe"); if (!np) { np = of_find_node_by_type(NULL, "qe"); if (!np) { dev_err(&ofdev->dev, "could not find 'qe' node\n"); kfree(qe_port); return -EINVAL; } } iprop = of_get_property(np, "brg-frequency", NULL); if (!iprop) { dev_err(&ofdev->dev, "missing brg-frequency in device tree\n"); kfree(qe_port); return -EINVAL; } if (*iprop) qe_port->port.uartclk = *iprop; else { /* * Older versions of U-Boot do not initialize the brg-frequency * property, so in this case we assume the BRG frequency is * half the QE bus frequency. */ iprop = of_get_property(np, "bus-frequency", NULL); if (!iprop) { dev_err(&ofdev->dev, "missing QE bus-frequency in device tree\n"); kfree(qe_port); return -EINVAL; } if (*iprop) qe_port->port.uartclk = *iprop / 2; else { dev_err(&ofdev->dev, "invalid QE bus-frequency in device tree\n"); kfree(qe_port); return -EINVAL; } } spin_lock_init(&qe_port->port.lock); qe_port->np = np; qe_port->port.dev = &ofdev->dev; qe_port->port.ops = &qe_uart_pops; qe_port->port.iotype = UPIO_MEM; qe_port->tx_nrfifos = TX_NUM_FIFO; qe_port->tx_fifosize = TX_BUF_SIZE; qe_port->rx_nrfifos = RX_NUM_FIFO; qe_port->rx_fifosize = RX_BUF_SIZE; qe_port->wait_closing = UCC_WAIT_CLOSING; qe_port->port.fifosize = 512; qe_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP; qe_port->us_info.ucc_num = qe_port->ucc_num; qe_port->us_info.regs = (phys_addr_t) res.start; qe_port->us_info.irq = qe_port->port.irq; qe_port->us_info.rx_bd_ring_len = qe_port->rx_nrfifos; qe_port->us_info.tx_bd_ring_len = qe_port->tx_nrfifos; /* Make sure ucc_slow_init() initializes both TX and RX */ qe_port->us_info.init_tx = 1; qe_port->us_info.init_rx = 1; /* Add the port to the uart sub-system. This will cause * qe_uart_config_port() to be called, so the us_info structure must * be initialized. */ ret = uart_add_one_port(&ucc_uart_driver, &qe_port->port); if (ret) { dev_err(&ofdev->dev, "could not add /dev/ttyQE%u\n", qe_port->port.line); kfree(qe_port); return ret; } dev_set_drvdata(&ofdev->dev, qe_port); dev_info(&ofdev->dev, "UCC%u assigned to /dev/ttyQE%u\n", qe_port->ucc_num + 1, qe_port->port.line); /* Display the mknod command for this device */ dev_dbg(&ofdev->dev, "mknod command is 'mknod /dev/ttyQE%u c %u %u'\n", qe_port->port.line, SERIAL_QE_MAJOR, SERIAL_QE_MINOR + qe_port->port.line); return 0; } static int ucc_uart_remove(struct of_device *ofdev) { struct uart_qe_port *qe_port = dev_get_drvdata(&ofdev->dev); dev_info(&ofdev->dev, "removing /dev/ttyQE%u\n", qe_port->port.line); uart_remove_one_port(&ucc_uart_driver, &qe_port->port); dev_set_drvdata(&ofdev->dev, NULL); kfree(qe_port); return 0; } static struct of_device_id ucc_uart_match[] = { { .type = "serial", .compatible = "ucc_uart", }, {}, }; MODULE_DEVICE_TABLE(of, ucc_uart_match); static struct of_platform_driver ucc_uart_of_driver = { .owner = THIS_MODULE, .name = "ucc_uart", .match_table = ucc_uart_match, .probe = ucc_uart_probe, .remove = ucc_uart_remove, }; static int __init ucc_uart_init(void) { int ret; printk(KERN_INFO "Freescale QUICC Engine UART device driver\n"); #ifdef LOOPBACK printk(KERN_INFO "ucc-uart: Using loopback mode\n"); #endif ret = uart_register_driver(&ucc_uart_driver); if (ret) { printk(KERN_ERR "ucc-uart: could not register UART driver\n"); return ret; } ret = of_register_platform_driver(&ucc_uart_of_driver); if (ret) printk(KERN_ERR "ucc-uart: could not register platform driver\n"); return ret; } static void __exit ucc_uart_exit(void) { printk(KERN_INFO "Freescale QUICC Engine UART device driver unloading\n"); of_unregister_platform_driver(&ucc_uart_of_driver); uart_unregister_driver(&ucc_uart_driver); } module_init(ucc_uart_init); module_exit(ucc_uart_exit); MODULE_DESCRIPTION("Freescale QUICC Engine (QE) UART"); MODULE_AUTHOR("Timur Tabi <timur@freescale.com>"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS_CHARDEV_MAJOR(SERIAL_QE_MAJOR);