// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2012-2015 Spreadtrum Communications Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* device name */ #define UART_NR_MAX 8 #define SPRD_TTY_NAME "ttyS" #define SPRD_FIFO_SIZE 128 #define SPRD_DEF_RATE 26000000 #define SPRD_BAUD_IO_LIMIT 3000000 #define SPRD_TIMEOUT 256000 /* the offset of serial registers and BITs for them */ /* data registers */ #define SPRD_TXD 0x0000 #define SPRD_RXD 0x0004 /* line status register and its BITs */ #define SPRD_LSR 0x0008 #define SPRD_LSR_OE BIT(4) #define SPRD_LSR_FE BIT(3) #define SPRD_LSR_PE BIT(2) #define SPRD_LSR_BI BIT(7) #define SPRD_LSR_TX_OVER BIT(15) /* data number in TX and RX fifo */ #define SPRD_STS1 0x000C #define SPRD_RX_FIFO_CNT_MASK GENMASK(7, 0) #define SPRD_TX_FIFO_CNT_MASK GENMASK(15, 8) /* interrupt enable register and its BITs */ #define SPRD_IEN 0x0010 #define SPRD_IEN_RX_FULL BIT(0) #define SPRD_IEN_TX_EMPTY BIT(1) #define SPRD_IEN_BREAK_DETECT BIT(7) #define SPRD_IEN_TIMEOUT BIT(13) /* interrupt clear register */ #define SPRD_ICLR 0x0014 #define SPRD_ICLR_TIMEOUT BIT(13) /* line control register */ #define SPRD_LCR 0x0018 #define SPRD_LCR_STOP_1BIT 0x10 #define SPRD_LCR_STOP_2BIT 0x30 #define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3)) #define SPRD_LCR_DATA_LEN5 0x0 #define SPRD_LCR_DATA_LEN6 0x4 #define SPRD_LCR_DATA_LEN7 0x8 #define SPRD_LCR_DATA_LEN8 0xc #define SPRD_LCR_PARITY (BIT(0) | BIT(1)) #define SPRD_LCR_PARITY_EN 0x2 #define SPRD_LCR_EVEN_PAR 0x0 #define SPRD_LCR_ODD_PAR 0x1 /* control register 1 */ #define SPRD_CTL1 0x001C #define SPRD_DMA_EN BIT(15) #define SPRD_LOOPBACK_EN BIT(14) #define RX_HW_FLOW_CTL_THLD BIT(6) #define RX_HW_FLOW_CTL_EN BIT(7) #define TX_HW_FLOW_CTL_EN BIT(8) #define RX_TOUT_THLD_DEF 0x3E00 #define RX_HFC_THLD_DEF 0x40 /* fifo threshold register */ #define SPRD_CTL2 0x0020 #define THLD_TX_EMPTY 0x40 #define THLD_TX_EMPTY_SHIFT 8 #define THLD_RX_FULL 0x40 #define THLD_RX_FULL_MASK GENMASK(6, 0) /* config baud rate register */ #define SPRD_CLKD0 0x0024 #define SPRD_CLKD0_MASK GENMASK(15, 0) #define SPRD_CLKD1 0x0028 #define SPRD_CLKD1_MASK GENMASK(20, 16) #define SPRD_CLKD1_SHIFT 16 /* interrupt mask status register */ #define SPRD_IMSR 0x002C #define SPRD_IMSR_RX_FIFO_FULL BIT(0) #define SPRD_IMSR_TX_FIFO_EMPTY BIT(1) #define SPRD_IMSR_BREAK_DETECT BIT(7) #define SPRD_IMSR_TIMEOUT BIT(13) #define SPRD_DEFAULT_SOURCE_CLK 26000000 #define SPRD_RX_DMA_STEP 1 #define SPRD_RX_FIFO_FULL 1 #define SPRD_TX_FIFO_FULL 0x20 #define SPRD_UART_RX_SIZE (UART_XMIT_SIZE / 4) struct sprd_uart_dma { struct dma_chan *chn; unsigned char *virt; dma_addr_t phys_addr; dma_cookie_t cookie; u32 trans_len; bool enable; }; struct sprd_uart_port { struct uart_port port; char name[16]; struct clk *clk; struct sprd_uart_dma tx_dma; struct sprd_uart_dma rx_dma; dma_addr_t pos; unsigned char *rx_buf_tail; }; static struct sprd_uart_port *sprd_port[UART_NR_MAX]; static int sprd_ports_num; static int sprd_start_dma_rx(struct uart_port *port); static int sprd_tx_dma_config(struct uart_port *port); static inline unsigned int serial_in(struct uart_port *port, unsigned int offset) { return readl_relaxed(port->membase + offset); } static inline void serial_out(struct uart_port *port, unsigned int offset, int value) { writel_relaxed(value, port->membase + offset); } static unsigned int sprd_tx_empty(struct uart_port *port) { if (serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK) return 0; else return TIOCSER_TEMT; } static unsigned int sprd_get_mctrl(struct uart_port *port) { return TIOCM_DSR | TIOCM_CTS; } static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl) { u32 val = serial_in(port, SPRD_CTL1); if (mctrl & TIOCM_LOOP) val |= SPRD_LOOPBACK_EN; else val &= ~SPRD_LOOPBACK_EN; serial_out(port, SPRD_CTL1, val); } static void sprd_stop_rx(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); unsigned int ien, iclr; if (sp->rx_dma.enable) dmaengine_terminate_all(sp->rx_dma.chn); iclr = serial_in(port, SPRD_ICLR); ien = serial_in(port, SPRD_IEN); ien &= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT); iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT; serial_out(port, SPRD_IEN, ien); serial_out(port, SPRD_ICLR, iclr); } static void sprd_uart_dma_enable(struct uart_port *port, bool enable) { u32 val = serial_in(port, SPRD_CTL1); if (enable) val |= SPRD_DMA_EN; else val &= ~SPRD_DMA_EN; serial_out(port, SPRD_CTL1, val); } static void sprd_stop_tx_dma(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); struct dma_tx_state state; u32 trans_len; dmaengine_pause(sp->tx_dma.chn); dmaengine_tx_status(sp->tx_dma.chn, sp->tx_dma.cookie, &state); if (state.residue) { trans_len = state.residue - sp->tx_dma.phys_addr; uart_xmit_advance(port, trans_len); dma_unmap_single(port->dev, sp->tx_dma.phys_addr, sp->tx_dma.trans_len, DMA_TO_DEVICE); } dmaengine_terminate_all(sp->tx_dma.chn); sp->tx_dma.trans_len = 0; } static int sprd_tx_buf_remap(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); struct circ_buf *xmit = &port->state->xmit; sp->tx_dma.trans_len = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); sp->tx_dma.phys_addr = dma_map_single(port->dev, (void *)&(xmit->buf[xmit->tail]), sp->tx_dma.trans_len, DMA_TO_DEVICE); return dma_mapping_error(port->dev, sp->tx_dma.phys_addr); } static void sprd_complete_tx_dma(void *data) { struct uart_port *port = (struct uart_port *)data; struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); struct circ_buf *xmit = &port->state->xmit; unsigned long flags; spin_lock_irqsave(&port->lock, flags); dma_unmap_single(port->dev, sp->tx_dma.phys_addr, sp->tx_dma.trans_len, DMA_TO_DEVICE); uart_xmit_advance(port, sp->tx_dma.trans_len); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); if (uart_circ_empty(xmit) || sprd_tx_buf_remap(port) || sprd_tx_dma_config(port)) sp->tx_dma.trans_len = 0; spin_unlock_irqrestore(&port->lock, flags); } static int sprd_uart_dma_submit(struct uart_port *port, struct sprd_uart_dma *ud, u32 trans_len, enum dma_transfer_direction direction, dma_async_tx_callback callback) { struct dma_async_tx_descriptor *dma_des; unsigned long flags; flags = SPRD_DMA_FLAGS(SPRD_DMA_CHN_MODE_NONE, SPRD_DMA_NO_TRG, SPRD_DMA_FRAG_REQ, SPRD_DMA_TRANS_INT); dma_des = dmaengine_prep_slave_single(ud->chn, ud->phys_addr, trans_len, direction, flags); if (!dma_des) return -ENODEV; dma_des->callback = callback; dma_des->callback_param = port; ud->cookie = dmaengine_submit(dma_des); if (dma_submit_error(ud->cookie)) return dma_submit_error(ud->cookie); dma_async_issue_pending(ud->chn); return 0; } static int sprd_tx_dma_config(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); u32 burst = sp->tx_dma.trans_len > SPRD_TX_FIFO_FULL ? SPRD_TX_FIFO_FULL : sp->tx_dma.trans_len; int ret; struct dma_slave_config cfg = { .dst_addr = port->mapbase + SPRD_TXD, .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, .src_maxburst = burst, }; ret = dmaengine_slave_config(sp->tx_dma.chn, &cfg); if (ret < 0) return ret; return sprd_uart_dma_submit(port, &sp->tx_dma, sp->tx_dma.trans_len, DMA_MEM_TO_DEV, sprd_complete_tx_dma); } static void sprd_start_tx_dma(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); struct circ_buf *xmit = &port->state->xmit; if (port->x_char) { serial_out(port, SPRD_TXD, port->x_char); port->icount.tx++; port->x_char = 0; return; } if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { sprd_stop_tx_dma(port); return; } if (sp->tx_dma.trans_len) return; if (sprd_tx_buf_remap(port) || sprd_tx_dma_config(port)) sp->tx_dma.trans_len = 0; } static void sprd_rx_full_thld(struct uart_port *port, u32 thld) { u32 val = serial_in(port, SPRD_CTL2); val &= ~THLD_RX_FULL_MASK; val |= thld & THLD_RX_FULL_MASK; serial_out(port, SPRD_CTL2, val); } static int sprd_rx_alloc_buf(struct sprd_uart_port *sp) { sp->rx_dma.virt = dma_alloc_coherent(sp->port.dev, SPRD_UART_RX_SIZE, &sp->rx_dma.phys_addr, GFP_KERNEL); if (!sp->rx_dma.virt) return -ENOMEM; return 0; } static void sprd_rx_free_buf(struct sprd_uart_port *sp) { if (sp->rx_dma.virt) dma_free_coherent(sp->port.dev, SPRD_UART_RX_SIZE, sp->rx_dma.virt, sp->rx_dma.phys_addr); sp->rx_dma.virt = NULL; } static int sprd_rx_dma_config(struct uart_port *port, u32 burst) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); struct dma_slave_config cfg = { .src_addr = port->mapbase + SPRD_RXD, .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE, .src_maxburst = burst, }; return dmaengine_slave_config(sp->rx_dma.chn, &cfg); } static void sprd_uart_dma_rx(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); struct tty_port *tty = &port->state->port; port->icount.rx += sp->rx_dma.trans_len; tty_insert_flip_string(tty, sp->rx_buf_tail, sp->rx_dma.trans_len); tty_flip_buffer_push(tty); } static void sprd_uart_dma_irq(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); struct dma_tx_state state; enum dma_status status; status = dmaengine_tx_status(sp->rx_dma.chn, sp->rx_dma.cookie, &state); if (status == DMA_ERROR) sprd_stop_rx(port); if (!state.residue && sp->pos == sp->rx_dma.phys_addr) return; if (!state.residue) { sp->rx_dma.trans_len = SPRD_UART_RX_SIZE + sp->rx_dma.phys_addr - sp->pos; sp->pos = sp->rx_dma.phys_addr; } else { sp->rx_dma.trans_len = state.residue - sp->pos; sp->pos = state.residue; } sprd_uart_dma_rx(port); sp->rx_buf_tail += sp->rx_dma.trans_len; } static void sprd_complete_rx_dma(void *data) { struct uart_port *port = (struct uart_port *)data; struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); struct dma_tx_state state; enum dma_status status; unsigned long flags; spin_lock_irqsave(&port->lock, flags); status = dmaengine_tx_status(sp->rx_dma.chn, sp->rx_dma.cookie, &state); if (status != DMA_COMPLETE) { sprd_stop_rx(port); spin_unlock_irqrestore(&port->lock, flags); return; } if (sp->pos != sp->rx_dma.phys_addr) { sp->rx_dma.trans_len = SPRD_UART_RX_SIZE + sp->rx_dma.phys_addr - sp->pos; sprd_uart_dma_rx(port); sp->rx_buf_tail += sp->rx_dma.trans_len; } if (sprd_start_dma_rx(port)) sprd_stop_rx(port); spin_unlock_irqrestore(&port->lock, flags); } static int sprd_start_dma_rx(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); int ret; if (!sp->rx_dma.enable) return 0; sp->pos = sp->rx_dma.phys_addr; sp->rx_buf_tail = sp->rx_dma.virt; sprd_rx_full_thld(port, SPRD_RX_FIFO_FULL); ret = sprd_rx_dma_config(port, SPRD_RX_DMA_STEP); if (ret) return ret; return sprd_uart_dma_submit(port, &sp->rx_dma, SPRD_UART_RX_SIZE, DMA_DEV_TO_MEM, sprd_complete_rx_dma); } static void sprd_release_dma(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); sprd_uart_dma_enable(port, false); if (sp->rx_dma.enable) dma_release_channel(sp->rx_dma.chn); if (sp->tx_dma.enable) dma_release_channel(sp->tx_dma.chn); sp->tx_dma.enable = false; sp->rx_dma.enable = false; } static void sprd_request_dma(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); sp->tx_dma.enable = true; sp->rx_dma.enable = true; sp->tx_dma.chn = dma_request_chan(port->dev, "tx"); if (IS_ERR(sp->tx_dma.chn)) { dev_err(port->dev, "request TX DMA channel failed, ret = %ld\n", PTR_ERR(sp->tx_dma.chn)); sp->tx_dma.enable = false; } sp->rx_dma.chn = dma_request_chan(port->dev, "rx"); if (IS_ERR(sp->rx_dma.chn)) { dev_err(port->dev, "request RX DMA channel failed, ret = %ld\n", PTR_ERR(sp->rx_dma.chn)); sp->rx_dma.enable = false; } } static void sprd_stop_tx(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); unsigned int ien, iclr; if (sp->tx_dma.enable) { sprd_stop_tx_dma(port); return; } iclr = serial_in(port, SPRD_ICLR); ien = serial_in(port, SPRD_IEN); iclr |= SPRD_IEN_TX_EMPTY; ien &= ~SPRD_IEN_TX_EMPTY; serial_out(port, SPRD_IEN, ien); serial_out(port, SPRD_ICLR, iclr); } static void sprd_start_tx(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); unsigned int ien; if (sp->tx_dma.enable) { sprd_start_tx_dma(port); return; } ien = serial_in(port, SPRD_IEN); if (!(ien & SPRD_IEN_TX_EMPTY)) { ien |= SPRD_IEN_TX_EMPTY; serial_out(port, SPRD_IEN, ien); } } /* The Sprd serial does not support this function. */ static void sprd_break_ctl(struct uart_port *port, int break_state) { /* nothing to do */ } static int handle_lsr_errors(struct uart_port *port, unsigned int *flag, unsigned int *lsr) { int ret = 0; /* statistics */ if (*lsr & SPRD_LSR_BI) { *lsr &= ~(SPRD_LSR_FE | SPRD_LSR_PE); port->icount.brk++; ret = uart_handle_break(port); if (ret) return ret; } else if (*lsr & SPRD_LSR_PE) port->icount.parity++; else if (*lsr & SPRD_LSR_FE) port->icount.frame++; if (*lsr & SPRD_LSR_OE) port->icount.overrun++; /* mask off conditions which should be ignored */ *lsr &= port->read_status_mask; if (*lsr & SPRD_LSR_BI) *flag = TTY_BREAK; else if (*lsr & SPRD_LSR_PE) *flag = TTY_PARITY; else if (*lsr & SPRD_LSR_FE) *flag = TTY_FRAME; return ret; } static inline void sprd_rx(struct uart_port *port) { struct sprd_uart_port *sp = container_of(port, struct sprd_uart_port, port); struct tty_port *tty = &port->state->port; unsigned int ch, flag, lsr, max_count = SPRD_TIMEOUT; if (sp->rx_dma.enable) { sprd_uart_dma_irq(port); return; } while ((serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK) && max_count--) { lsr = serial_in(port, SPRD_LSR); ch = serial_in(port, SPRD_RXD); flag = TTY_NORMAL; port->icount.rx++; if (lsr & (SPRD_LSR_BI | SPRD_LSR_PE | SPRD_LSR_FE | SPRD_LSR_OE)) if (handle_lsr_errors(port, &flag, &lsr)) continue; if (uart_handle_sysrq_char(port, ch)) continue; uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag); } tty_flip_buffer_push(tty); } static inline void sprd_tx(struct uart_port *port) { u8 ch; uart_port_tx_limited(port, ch, THLD_TX_EMPTY, true, serial_out(port, SPRD_TXD, ch), ({})); } /* this handles the interrupt from one port */ static irqreturn_t sprd_handle_irq(int irq, void *dev_id) { struct uart_port *port = dev_id; unsigned int ims; spin_lock(&port->lock); ims = serial_in(port, SPRD_IMSR); if (!ims) { spin_unlock(&port->lock); return IRQ_NONE; } if (ims & SPRD_IMSR_TIMEOUT) serial_out(port, SPRD_ICLR, SPRD_ICLR_TIMEOUT); if (ims & SPRD_IMSR_BREAK_DETECT) serial_out(port, SPRD_ICLR, SPRD_IMSR_BREAK_DETECT); if (ims & (SPRD_IMSR_RX_FIFO_FULL | SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT)) sprd_rx(port); if (ims & SPRD_IMSR_TX_FIFO_EMPTY) sprd_tx(port); spin_unlock(&port->lock); return IRQ_HANDLED; } static void sprd_uart_dma_startup(struct uart_port *port, struct sprd_uart_port *sp) { int ret; sprd_request_dma(port); if (!(sp->rx_dma.enable || sp->tx_dma.enable)) return; ret = sprd_start_dma_rx(port); if (ret) { sp->rx_dma.enable = false; dma_release_channel(sp->rx_dma.chn); dev_warn(port->dev, "fail to start RX dma mode\n"); } sprd_uart_dma_enable(port, true); } static int sprd_startup(struct uart_port *port) { int ret = 0; unsigned int ien, fc; unsigned int timeout; struct sprd_uart_port *sp; unsigned long flags; serial_out(port, SPRD_CTL2, THLD_TX_EMPTY << THLD_TX_EMPTY_SHIFT | THLD_RX_FULL); /* clear rx fifo */ timeout = SPRD_TIMEOUT; while (timeout-- && serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK) serial_in(port, SPRD_RXD); /* clear tx fifo */ timeout = SPRD_TIMEOUT; while (timeout-- && serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK) cpu_relax(); /* clear interrupt */ serial_out(port, SPRD_IEN, 0); serial_out(port, SPRD_ICLR, ~0); /* allocate irq */ sp = container_of(port, struct sprd_uart_port, port); snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line); sprd_uart_dma_startup(port, sp); ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq, IRQF_SHARED, sp->name, port); if (ret) { dev_err(port->dev, "fail to request serial irq %d, ret=%d\n", port->irq, ret); return ret; } fc = serial_in(port, SPRD_CTL1); fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF; serial_out(port, SPRD_CTL1, fc); /* enable interrupt */ spin_lock_irqsave(&port->lock, flags); ien = serial_in(port, SPRD_IEN); ien |= SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT; if (!sp->rx_dma.enable) ien |= SPRD_IEN_RX_FULL; serial_out(port, SPRD_IEN, ien); spin_unlock_irqrestore(&port->lock, flags); return 0; } static void sprd_shutdown(struct uart_port *port) { sprd_release_dma(port); serial_out(port, SPRD_IEN, 0); serial_out(port, SPRD_ICLR, ~0); devm_free_irq(port->dev, port->irq, port); } static void sprd_set_termios(struct uart_port *port, struct ktermios *termios, const struct ktermios *old) { unsigned int baud, quot; unsigned int lcr = 0, fc; unsigned long flags; /* ask the core to calculate the divisor for us */ baud = uart_get_baud_rate(port, termios, old, 0, SPRD_BAUD_IO_LIMIT); quot = port->uartclk / baud; /* set data length */ switch (termios->c_cflag & CSIZE) { case CS5: lcr |= SPRD_LCR_DATA_LEN5; break; case CS6: lcr |= SPRD_LCR_DATA_LEN6; break; case CS7: lcr |= SPRD_LCR_DATA_LEN7; break; case CS8: default: lcr |= SPRD_LCR_DATA_LEN8; break; } /* calculate stop bits */ lcr &= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT); if (termios->c_cflag & CSTOPB) lcr |= SPRD_LCR_STOP_2BIT; else lcr |= SPRD_LCR_STOP_1BIT; /* calculate parity */ lcr &= ~SPRD_LCR_PARITY; termios->c_cflag &= ~CMSPAR; /* no support mark/space */ if (termios->c_cflag & PARENB) { lcr |= SPRD_LCR_PARITY_EN; if (termios->c_cflag & PARODD) lcr |= SPRD_LCR_ODD_PAR; else lcr |= SPRD_LCR_EVEN_PAR; } spin_lock_irqsave(&port->lock, flags); /* update the per-port timeout */ uart_update_timeout(port, termios->c_cflag, baud); port->read_status_mask = SPRD_LSR_OE; if (termios->c_iflag & INPCK) port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE; if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) port->read_status_mask |= SPRD_LSR_BI; /* characters to ignore */ port->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE; if (termios->c_iflag & IGNBRK) { port->ignore_status_mask |= SPRD_LSR_BI; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) port->ignore_status_mask |= SPRD_LSR_OE; } /* flow control */ fc = serial_in(port, SPRD_CTL1); fc &= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN); if (termios->c_cflag & CRTSCTS) { fc |= RX_HW_FLOW_CTL_THLD; fc |= RX_HW_FLOW_CTL_EN; fc |= TX_HW_FLOW_CTL_EN; } /* clock divider bit0~bit15 */ serial_out(port, SPRD_CLKD0, quot & SPRD_CLKD0_MASK); /* clock divider bit16~bit20 */ serial_out(port, SPRD_CLKD1, (quot & SPRD_CLKD1_MASK) >> SPRD_CLKD1_SHIFT); serial_out(port, SPRD_LCR, lcr); fc |= RX_TOUT_THLD_DEF | RX_HFC_THLD_DEF; serial_out(port, SPRD_CTL1, fc); spin_unlock_irqrestore(&port->lock, flags); /* Don't rewrite B0 */ if (tty_termios_baud_rate(termios)) tty_termios_encode_baud_rate(termios, baud, baud); } static const char *sprd_type(struct uart_port *port) { return "SPX"; } static void sprd_release_port(struct uart_port *port) { /* nothing to do */ } static int sprd_request_port(struct uart_port *port) { return 0; } static void sprd_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) port->type = PORT_SPRD; } static int sprd_verify_port(struct uart_port *port, struct serial_struct *ser) { if (ser->type != PORT_SPRD) return -EINVAL; if (port->irq != ser->irq) return -EINVAL; if (port->iotype != ser->io_type) return -EINVAL; return 0; } static void sprd_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { struct sprd_uart_port *sup = container_of(port, struct sprd_uart_port, port); switch (state) { case UART_PM_STATE_ON: clk_prepare_enable(sup->clk); break; case UART_PM_STATE_OFF: clk_disable_unprepare(sup->clk); break; } } #ifdef CONFIG_CONSOLE_POLL static int sprd_poll_init(struct uart_port *port) { if (port->state->pm_state != UART_PM_STATE_ON) { sprd_pm(port, UART_PM_STATE_ON, 0); port->state->pm_state = UART_PM_STATE_ON; } return 0; } static int sprd_poll_get_char(struct uart_port *port) { while (!(serial_in(port, SPRD_STS1) & SPRD_RX_FIFO_CNT_MASK)) cpu_relax(); return serial_in(port, SPRD_RXD); } static void sprd_poll_put_char(struct uart_port *port, unsigned char ch) { while (serial_in(port, SPRD_STS1) & SPRD_TX_FIFO_CNT_MASK) cpu_relax(); serial_out(port, SPRD_TXD, ch); } #endif static const struct uart_ops serial_sprd_ops = { .tx_empty = sprd_tx_empty, .get_mctrl = sprd_get_mctrl, .set_mctrl = sprd_set_mctrl, .stop_tx = sprd_stop_tx, .start_tx = sprd_start_tx, .stop_rx = sprd_stop_rx, .break_ctl = sprd_break_ctl, .startup = sprd_startup, .shutdown = sprd_shutdown, .set_termios = sprd_set_termios, .type = sprd_type, .release_port = sprd_release_port, .request_port = sprd_request_port, .config_port = sprd_config_port, .verify_port = sprd_verify_port, .pm = sprd_pm, #ifdef CONFIG_CONSOLE_POLL .poll_init = sprd_poll_init, .poll_get_char = sprd_poll_get_char, .poll_put_char = sprd_poll_put_char, #endif }; #ifdef CONFIG_SERIAL_SPRD_CONSOLE static void wait_for_xmitr(struct uart_port *port) { unsigned int status, tmout = 10000; /* wait up to 10ms for the character(s) to be sent */ do { status = serial_in(port, SPRD_STS1); if (--tmout == 0) break; udelay(1); } while (status & SPRD_TX_FIFO_CNT_MASK); } static void sprd_console_putchar(struct uart_port *port, unsigned char ch) { wait_for_xmitr(port); serial_out(port, SPRD_TXD, ch); } static void sprd_console_write(struct console *co, const char *s, unsigned int count) { struct uart_port *port = &sprd_port[co->index]->port; int locked = 1; unsigned long flags; if (port->sysrq) locked = 0; else if (oops_in_progress) locked = spin_trylock_irqsave(&port->lock, flags); else spin_lock_irqsave(&port->lock, flags); uart_console_write(port, s, count, sprd_console_putchar); /* wait for transmitter to become empty */ wait_for_xmitr(port); if (locked) spin_unlock_irqrestore(&port->lock, flags); } static int sprd_console_setup(struct console *co, char *options) { struct sprd_uart_port *sprd_uart_port; int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; if (co->index >= UART_NR_MAX || co->index < 0) co->index = 0; sprd_uart_port = sprd_port[co->index]; if (!sprd_uart_port || !sprd_uart_port->port.membase) { pr_info("serial port %d not yet initialized\n", co->index); return -ENODEV; } if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); return uart_set_options(&sprd_uart_port->port, co, baud, parity, bits, flow); } static struct uart_driver sprd_uart_driver; static struct console sprd_console = { .name = SPRD_TTY_NAME, .write = sprd_console_write, .device = uart_console_device, .setup = sprd_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &sprd_uart_driver, }; static int __init sprd_serial_console_init(void) { register_console(&sprd_console); return 0; } console_initcall(sprd_serial_console_init); #define SPRD_CONSOLE (&sprd_console) /* Support for earlycon */ static void sprd_putc(struct uart_port *port, unsigned char c) { unsigned int timeout = SPRD_TIMEOUT; while (timeout-- && !(readl(port->membase + SPRD_LSR) & SPRD_LSR_TX_OVER)) cpu_relax(); writeb(c, port->membase + SPRD_TXD); } static void sprd_early_write(struct console *con, const char *s, unsigned int n) { struct earlycon_device *dev = con->data; uart_console_write(&dev->port, s, n, sprd_putc); } static int __init sprd_early_console_setup(struct earlycon_device *device, const char *opt) { if (!device->port.membase) return -ENODEV; device->con->write = sprd_early_write; return 0; } OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart", sprd_early_console_setup); #else /* !CONFIG_SERIAL_SPRD_CONSOLE */ #define SPRD_CONSOLE NULL #endif static struct uart_driver sprd_uart_driver = { .owner = THIS_MODULE, .driver_name = "sprd_serial", .dev_name = SPRD_TTY_NAME, .major = 0, .minor = 0, .nr = UART_NR_MAX, .cons = SPRD_CONSOLE, }; static int sprd_remove(struct platform_device *dev) { struct sprd_uart_port *sup = platform_get_drvdata(dev); if (sup) { uart_remove_one_port(&sprd_uart_driver, &sup->port); sprd_port[sup->port.line] = NULL; sprd_rx_free_buf(sup); sprd_ports_num--; } if (!sprd_ports_num) uart_unregister_driver(&sprd_uart_driver); return 0; } static bool sprd_uart_is_console(struct uart_port *uport) { struct console *cons = sprd_uart_driver.cons; if ((cons && cons->index >= 0 && cons->index == uport->line) || of_console_check(uport->dev->of_node, SPRD_TTY_NAME, uport->line)) return true; return false; } static int sprd_clk_init(struct uart_port *uport) { struct clk *clk_uart, *clk_parent; struct sprd_uart_port *u = container_of(uport, struct sprd_uart_port, port); clk_uart = devm_clk_get(uport->dev, "uart"); if (IS_ERR(clk_uart)) { dev_warn(uport->dev, "uart%d can't get uart clock\n", uport->line); clk_uart = NULL; } clk_parent = devm_clk_get(uport->dev, "source"); if (IS_ERR(clk_parent)) { dev_warn(uport->dev, "uart%d can't get source clock\n", uport->line); clk_parent = NULL; } if (!clk_uart || clk_set_parent(clk_uart, clk_parent)) uport->uartclk = SPRD_DEFAULT_SOURCE_CLK; else uport->uartclk = clk_get_rate(clk_uart); u->clk = devm_clk_get(uport->dev, "enable"); if (IS_ERR(u->clk)) { if (PTR_ERR(u->clk) == -EPROBE_DEFER) return -EPROBE_DEFER; dev_warn(uport->dev, "uart%d can't get enable clock\n", uport->line); /* To keep console alive even if the error occurred */ if (!sprd_uart_is_console(uport)) return PTR_ERR(u->clk); u->clk = NULL; } return 0; } static int sprd_probe(struct platform_device *pdev) { struct resource *res; struct uart_port *up; struct sprd_uart_port *sport; int irq; int index; int ret; index = of_alias_get_id(pdev->dev.of_node, "serial"); if (index < 0 || index >= UART_NR_MAX) { dev_err(&pdev->dev, "got a wrong serial alias id %d\n", index); return -EINVAL; } sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); if (!sport) return -ENOMEM; up = &sport->port; up->dev = &pdev->dev; up->line = index; up->type = PORT_SPRD; up->iotype = UPIO_MEM; up->uartclk = SPRD_DEF_RATE; up->fifosize = SPRD_FIFO_SIZE; up->ops = &serial_sprd_ops; up->flags = UPF_BOOT_AUTOCONF; up->has_sysrq = IS_ENABLED(CONFIG_SERIAL_SPRD_CONSOLE); ret = sprd_clk_init(up); if (ret) return ret; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); up->membase = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(up->membase)) return PTR_ERR(up->membase); up->mapbase = res->start; irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; up->irq = irq; /* * Allocate one dma buffer to prepare for receive transfer, in case * memory allocation failure at runtime. */ ret = sprd_rx_alloc_buf(sport); if (ret) return ret; if (!sprd_ports_num) { ret = uart_register_driver(&sprd_uart_driver); if (ret < 0) { pr_err("Failed to register SPRD-UART driver\n"); goto free_rx_buf; } } sprd_ports_num++; sprd_port[index] = sport; ret = uart_add_one_port(&sprd_uart_driver, up); if (ret) goto clean_port; platform_set_drvdata(pdev, up); return 0; clean_port: sprd_port[index] = NULL; if (--sprd_ports_num == 0) uart_unregister_driver(&sprd_uart_driver); free_rx_buf: sprd_rx_free_buf(sport); return ret; } #ifdef CONFIG_PM_SLEEP static int sprd_suspend(struct device *dev) { struct sprd_uart_port *sup = dev_get_drvdata(dev); uart_suspend_port(&sprd_uart_driver, &sup->port); return 0; } static int sprd_resume(struct device *dev) { struct sprd_uart_port *sup = dev_get_drvdata(dev); uart_resume_port(&sprd_uart_driver, &sup->port); return 0; } #endif static SIMPLE_DEV_PM_OPS(sprd_pm_ops, sprd_suspend, sprd_resume); static const struct of_device_id serial_ids[] = { {.compatible = "sprd,sc9836-uart",}, {} }; MODULE_DEVICE_TABLE(of, serial_ids); static struct platform_driver sprd_platform_driver = { .probe = sprd_probe, .remove = sprd_remove, .driver = { .name = "sprd_serial", .of_match_table = serial_ids, .pm = &sprd_pm_ops, }, }; module_platform_driver(sprd_platform_driver); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");