// SPDX-License-Identifier: GPL-2.0+ /* * PIC32 Integrated Serial Driver. * * Copyright (C) 2015 Microchip Technology, Inc. * * Authors: * Sorin-Andrei Pistirica */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* UART name and device definitions */ #define PIC32_DEV_NAME "pic32-uart" #define PIC32_MAX_UARTS 6 #define PIC32_SDEV_NAME "ttyPIC" #define PIC32_UART_DFLT_BRATE 9600 #define PIC32_UART_TX_FIFO_DEPTH 8 #define PIC32_UART_RX_FIFO_DEPTH 8 #define PIC32_UART_MODE 0x00 #define PIC32_UART_STA 0x10 #define PIC32_UART_TX 0x20 #define PIC32_UART_RX 0x30 #define PIC32_UART_BRG 0x40 /* struct pic32_sport - pic32 serial port descriptor * @port: uart port descriptor * @idx: port index * @irq_fault: virtual fault interrupt number * @irq_fault_name: irq fault name * @irq_rx: virtual rx interrupt number * @irq_rx_name: irq rx name * @irq_tx: virtual tx interrupt number * @irq_tx_name: irq tx name * @cts_gpiod: clear to send GPIO * @dev: device descriptor **/ struct pic32_sport { struct uart_port port; int idx; int irq_fault; const char *irq_fault_name; int irq_rx; const char *irq_rx_name; int irq_tx; const char *irq_tx_name; bool enable_tx_irq; struct gpio_desc *cts_gpiod; struct clk *clk; struct device *dev; }; static inline struct pic32_sport *to_pic32_sport(struct uart_port *port) { return container_of(port, struct pic32_sport, port); } static inline void pic32_uart_writel(struct pic32_sport *sport, u32 reg, u32 val) { __raw_writel(val, sport->port.membase + reg); } static inline u32 pic32_uart_readl(struct pic32_sport *sport, u32 reg) { return __raw_readl(sport->port.membase + reg); } /* pic32 uart mode register bits */ #define PIC32_UART_MODE_ON BIT(15) #define PIC32_UART_MODE_FRZ BIT(14) #define PIC32_UART_MODE_SIDL BIT(13) #define PIC32_UART_MODE_IREN BIT(12) #define PIC32_UART_MODE_RTSMD BIT(11) #define PIC32_UART_MODE_RESV1 BIT(10) #define PIC32_UART_MODE_UEN1 BIT(9) #define PIC32_UART_MODE_UEN0 BIT(8) #define PIC32_UART_MODE_WAKE BIT(7) #define PIC32_UART_MODE_LPBK BIT(6) #define PIC32_UART_MODE_ABAUD BIT(5) #define PIC32_UART_MODE_RXINV BIT(4) #define PIC32_UART_MODE_BRGH BIT(3) #define PIC32_UART_MODE_PDSEL1 BIT(2) #define PIC32_UART_MODE_PDSEL0 BIT(1) #define PIC32_UART_MODE_STSEL BIT(0) /* pic32 uart status register bits */ #define PIC32_UART_STA_UTXISEL1 BIT(15) #define PIC32_UART_STA_UTXISEL0 BIT(14) #define PIC32_UART_STA_UTXINV BIT(13) #define PIC32_UART_STA_URXEN BIT(12) #define PIC32_UART_STA_UTXBRK BIT(11) #define PIC32_UART_STA_UTXEN BIT(10) #define PIC32_UART_STA_UTXBF BIT(9) #define PIC32_UART_STA_TRMT BIT(8) #define PIC32_UART_STA_URXISEL1 BIT(7) #define PIC32_UART_STA_URXISEL0 BIT(6) #define PIC32_UART_STA_ADDEN BIT(5) #define PIC32_UART_STA_RIDLE BIT(4) #define PIC32_UART_STA_PERR BIT(3) #define PIC32_UART_STA_FERR BIT(2) #define PIC32_UART_STA_OERR BIT(1) #define PIC32_UART_STA_URXDA BIT(0) /* pic32_sport pointer for console use */ static struct pic32_sport *pic32_sports[PIC32_MAX_UARTS]; static inline void pic32_wait_deplete_txbuf(struct pic32_sport *sport) { /* wait for tx empty, otherwise chars will be lost or corrupted */ while (!(pic32_uart_readl(sport, PIC32_UART_STA) & PIC32_UART_STA_TRMT)) udelay(1); } /* serial core request to check if uart tx buffer is empty */ static unsigned int pic32_uart_tx_empty(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); u32 val = pic32_uart_readl(sport, PIC32_UART_STA); return (val & PIC32_UART_STA_TRMT) ? 1 : 0; } /* serial core request to set UART outputs */ static void pic32_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) { struct pic32_sport *sport = to_pic32_sport(port); /* set loopback mode */ if (mctrl & TIOCM_LOOP) pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), PIC32_UART_MODE_LPBK); else pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_LPBK); } /* serial core request to return the state of misc UART input pins */ static unsigned int pic32_uart_get_mctrl(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); unsigned int mctrl = 0; /* get the state of CTS input pin for this port */ if (!sport->cts_gpiod) mctrl |= TIOCM_CTS; else if (gpiod_get_value(sport->cts_gpiod)) mctrl |= TIOCM_CTS; /* DSR and CD are not supported in PIC32, so return 1 * RI is not supported in PIC32, so return 0 */ mctrl |= TIOCM_CD; mctrl |= TIOCM_DSR; return mctrl; } /* stop tx and start tx are not called in pairs, therefore a flag indicates * the status of irq to control the irq-depth. */ static inline void pic32_uart_irqtxen(struct pic32_sport *sport, u8 en) { if (en && !sport->enable_tx_irq) { enable_irq(sport->irq_tx); sport->enable_tx_irq = true; } else if (!en && sport->enable_tx_irq) { /* use disable_irq_nosync() and not disable_irq() to avoid self * imposed deadlock by not waiting for irq handler to end, * since this callback is called from interrupt context. */ disable_irq_nosync(sport->irq_tx); sport->enable_tx_irq = false; } } /* serial core request to disable tx ASAP (used for flow control) */ static void pic32_uart_stop_tx(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); if (!(pic32_uart_readl(sport, PIC32_UART_MODE) & PIC32_UART_MODE_ON)) return; if (!(pic32_uart_readl(sport, PIC32_UART_STA) & PIC32_UART_STA_UTXEN)) return; /* wait for tx empty */ pic32_wait_deplete_txbuf(sport); pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), PIC32_UART_STA_UTXEN); pic32_uart_irqtxen(sport, 0); } /* serial core request to (re)enable tx */ static void pic32_uart_start_tx(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); pic32_uart_irqtxen(sport, 1); pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA), PIC32_UART_STA_UTXEN); } /* serial core request to stop rx, called before port shutdown */ static void pic32_uart_stop_rx(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); /* disable rx interrupts */ disable_irq(sport->irq_rx); /* receiver Enable bit OFF */ pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), PIC32_UART_STA_URXEN); } /* serial core request to start/stop emitting break char */ static void pic32_uart_break_ctl(struct uart_port *port, int ctl) { struct pic32_sport *sport = to_pic32_sport(port); unsigned long flags; uart_port_lock_irqsave(port, &flags); if (ctl) pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA), PIC32_UART_STA_UTXBRK); else pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), PIC32_UART_STA_UTXBRK); uart_port_unlock_irqrestore(port, flags); } /* get port type in string format */ static const char *pic32_uart_type(struct uart_port *port) { return (port->type == PORT_PIC32) ? PIC32_DEV_NAME : NULL; } /* read all chars in rx fifo and send them to core */ static void pic32_uart_do_rx(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); struct tty_port *tty; unsigned int max_count; /* limit number of char read in interrupt, should not be * higher than fifo size anyway since we're much faster than * serial port */ max_count = PIC32_UART_RX_FIFO_DEPTH; uart_port_lock(port); tty = &port->state->port; do { u32 sta_reg, c; char flag; /* get overrun/fifo empty information from status register */ sta_reg = pic32_uart_readl(sport, PIC32_UART_STA); if (unlikely(sta_reg & PIC32_UART_STA_OERR)) { /* fifo reset is required to clear interrupt */ pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), PIC32_UART_STA_OERR); port->icount.overrun++; tty_insert_flip_char(tty, 0, TTY_OVERRUN); } /* Can at least one more character can be read? */ if (!(sta_reg & PIC32_UART_STA_URXDA)) break; /* read the character and increment the rx counter */ c = pic32_uart_readl(sport, PIC32_UART_RX); port->icount.rx++; flag = TTY_NORMAL; c &= 0xff; if (unlikely((sta_reg & PIC32_UART_STA_PERR) || (sta_reg & PIC32_UART_STA_FERR))) { /* do stats first */ if (sta_reg & PIC32_UART_STA_PERR) port->icount.parity++; if (sta_reg & PIC32_UART_STA_FERR) port->icount.frame++; /* update flag wrt read_status_mask */ sta_reg &= port->read_status_mask; if (sta_reg & PIC32_UART_STA_FERR) flag = TTY_FRAME; if (sta_reg & PIC32_UART_STA_PERR) flag = TTY_PARITY; } if (uart_handle_sysrq_char(port, c)) continue; if ((sta_reg & port->ignore_status_mask) == 0) tty_insert_flip_char(tty, c, flag); } while (--max_count); uart_port_unlock(port); tty_flip_buffer_push(tty); } /* fill tx fifo with chars to send, stop when fifo is about to be full * or when all chars have been sent. */ static void pic32_uart_do_tx(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); struct tty_port *tport = &port->state->port; unsigned int max_count = PIC32_UART_TX_FIFO_DEPTH; if (port->x_char) { pic32_uart_writel(sport, PIC32_UART_TX, port->x_char); port->icount.tx++; port->x_char = 0; return; } if (uart_tx_stopped(port)) { pic32_uart_stop_tx(port); return; } if (kfifo_is_empty(&tport->xmit_fifo)) goto txq_empty; /* keep stuffing chars into uart tx buffer * 1) until uart fifo is full * or * 2) until the circ buffer is empty * (all chars have been sent) * or * 3) until the max count is reached * (prevents lingering here for too long in certain cases) */ while (!(PIC32_UART_STA_UTXBF & pic32_uart_readl(sport, PIC32_UART_STA))) { unsigned char c; if (!uart_fifo_get(port, &c)) break; pic32_uart_writel(sport, PIC32_UART_TX, c); if (--max_count == 0) break; } if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) uart_write_wakeup(port); if (kfifo_is_empty(&tport->xmit_fifo)) goto txq_empty; return; txq_empty: pic32_uart_irqtxen(sport, 0); } /* RX interrupt handler */ static irqreturn_t pic32_uart_rx_interrupt(int irq, void *dev_id) { struct uart_port *port = dev_id; pic32_uart_do_rx(port); return IRQ_HANDLED; } /* TX interrupt handler */ static irqreturn_t pic32_uart_tx_interrupt(int irq, void *dev_id) { struct uart_port *port = dev_id; unsigned long flags; uart_port_lock_irqsave(port, &flags); pic32_uart_do_tx(port); uart_port_unlock_irqrestore(port, flags); return IRQ_HANDLED; } /* FAULT interrupt handler */ static irqreturn_t pic32_uart_fault_interrupt(int irq, void *dev_id) { /* do nothing: pic32_uart_do_rx() handles faults. */ return IRQ_HANDLED; } /* enable rx & tx operation on uart */ static void pic32_uart_en_and_unmask(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); pic32_uart_writel(sport, PIC32_SET(PIC32_UART_STA), PIC32_UART_STA_UTXEN | PIC32_UART_STA_URXEN); pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), PIC32_UART_MODE_ON); } /* disable rx & tx operation on uart */ static void pic32_uart_dsbl_and_mask(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); /* wait for tx empty, otherwise chars will be lost or corrupted */ pic32_wait_deplete_txbuf(sport); pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), PIC32_UART_STA_UTXEN | PIC32_UART_STA_URXEN); pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_ON); } /* serial core request to initialize uart and start rx operation */ static int pic32_uart_startup(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); u32 dflt_baud = (port->uartclk / PIC32_UART_DFLT_BRATE / 16) - 1; unsigned long flags; int ret; local_irq_save(flags); ret = clk_prepare_enable(sport->clk); if (ret) { local_irq_restore(flags); goto out_done; } /* clear status and mode registers */ pic32_uart_writel(sport, PIC32_UART_MODE, 0); pic32_uart_writel(sport, PIC32_UART_STA, 0); /* disable uart and mask all interrupts */ pic32_uart_dsbl_and_mask(port); /* set default baud */ pic32_uart_writel(sport, PIC32_UART_BRG, dflt_baud); local_irq_restore(flags); /* Each UART of a PIC32 has three interrupts therefore, * we setup driver to register the 3 irqs for the device. * * For each irq request_irq() is called with interrupt disabled. * And the irq is enabled as soon as we are ready to handle them. */ sport->enable_tx_irq = false; sport->irq_fault_name = kasprintf(GFP_KERNEL, "%s%d-fault", pic32_uart_type(port), sport->idx); if (!sport->irq_fault_name) { dev_err(port->dev, "%s: kasprintf err!", __func__); ret = -ENOMEM; goto out_disable_clk; } irq_set_status_flags(sport->irq_fault, IRQ_NOAUTOEN); ret = request_irq(sport->irq_fault, pic32_uart_fault_interrupt, IRQF_NO_THREAD, sport->irq_fault_name, port); if (ret) { dev_err(port->dev, "%s: request irq(%d) err! ret:%d name:%s\n", __func__, sport->irq_fault, ret, pic32_uart_type(port)); goto out_f; } sport->irq_rx_name = kasprintf(GFP_KERNEL, "%s%d-rx", pic32_uart_type(port), sport->idx); if (!sport->irq_rx_name) { dev_err(port->dev, "%s: kasprintf err!", __func__); ret = -ENOMEM; goto out_f; } irq_set_status_flags(sport->irq_rx, IRQ_NOAUTOEN); ret = request_irq(sport->irq_rx, pic32_uart_rx_interrupt, IRQF_NO_THREAD, sport->irq_rx_name, port); if (ret) { dev_err(port->dev, "%s: request irq(%d) err! ret:%d name:%s\n", __func__, sport->irq_rx, ret, pic32_uart_type(port)); goto out_r; } sport->irq_tx_name = kasprintf(GFP_KERNEL, "%s%d-tx", pic32_uart_type(port), sport->idx); if (!sport->irq_tx_name) { dev_err(port->dev, "%s: kasprintf err!", __func__); ret = -ENOMEM; goto out_r; } irq_set_status_flags(sport->irq_tx, IRQ_NOAUTOEN); ret = request_irq(sport->irq_tx, pic32_uart_tx_interrupt, IRQF_NO_THREAD, sport->irq_tx_name, port); if (ret) { dev_err(port->dev, "%s: request irq(%d) err! ret:%d name:%s\n", __func__, sport->irq_tx, ret, pic32_uart_type(port)); goto out_t; } local_irq_save(flags); /* set rx interrupt on first receive */ pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), PIC32_UART_STA_URXISEL1 | PIC32_UART_STA_URXISEL0); /* set interrupt on empty */ pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_STA), PIC32_UART_STA_UTXISEL1); /* enable all interrupts and eanable uart */ pic32_uart_en_and_unmask(port); local_irq_restore(flags); enable_irq(sport->irq_rx); return 0; out_t: free_irq(sport->irq_tx, port); kfree(sport->irq_tx_name); out_r: free_irq(sport->irq_rx, port); kfree(sport->irq_rx_name); out_f: free_irq(sport->irq_fault, port); kfree(sport->irq_fault_name); out_disable_clk: clk_disable_unprepare(sport->clk); out_done: return ret; } /* serial core request to flush & disable uart */ static void pic32_uart_shutdown(struct uart_port *port) { struct pic32_sport *sport = to_pic32_sport(port); unsigned long flags; /* disable uart */ uart_port_lock_irqsave(port, &flags); pic32_uart_dsbl_and_mask(port); uart_port_unlock_irqrestore(port, flags); clk_disable_unprepare(sport->clk); /* free all 3 interrupts for this UART */ free_irq(sport->irq_fault, port); kfree(sport->irq_fault_name); free_irq(sport->irq_tx, port); kfree(sport->irq_tx_name); free_irq(sport->irq_rx, port); kfree(sport->irq_rx_name); } /* serial core request to change current uart setting */ static void pic32_uart_set_termios(struct uart_port *port, struct ktermios *new, const struct ktermios *old) { struct pic32_sport *sport = to_pic32_sport(port); unsigned int baud; unsigned int quot; unsigned long flags; uart_port_lock_irqsave(port, &flags); /* disable uart and mask all interrupts while changing speed */ pic32_uart_dsbl_and_mask(port); /* stop bit options */ if (new->c_cflag & CSTOPB) pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), PIC32_UART_MODE_STSEL); else pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_STSEL); /* parity options */ if (new->c_cflag & PARENB) { if (new->c_cflag & PARODD) { pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), PIC32_UART_MODE_PDSEL1); pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_PDSEL0); } else { pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), PIC32_UART_MODE_PDSEL0); pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_PDSEL1); } } else { pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_PDSEL1 | PIC32_UART_MODE_PDSEL0); } /* if hw flow ctrl, then the pins must be specified in device tree */ if ((new->c_cflag & CRTSCTS) && sport->cts_gpiod) { /* enable hardware flow control */ pic32_uart_writel(sport, PIC32_SET(PIC32_UART_MODE), PIC32_UART_MODE_UEN1); pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_UEN0); pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_RTSMD); } else { /* disable hardware flow control */ pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_UEN1); pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_UEN0); pic32_uart_writel(sport, PIC32_CLR(PIC32_UART_MODE), PIC32_UART_MODE_RTSMD); } /* Always 8-bit */ new->c_cflag |= CS8; /* Mark/Space parity is not supported */ new->c_cflag &= ~CMSPAR; /* update baud */ baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16); quot = uart_get_divisor(port, baud) - 1; pic32_uart_writel(sport, PIC32_UART_BRG, quot); uart_update_timeout(port, new->c_cflag, baud); if (tty_termios_baud_rate(new)) tty_termios_encode_baud_rate(new, baud, baud); /* enable uart */ pic32_uart_en_and_unmask(port); uart_port_unlock_irqrestore(port, flags); } /* serial core request to claim uart iomem */ static int pic32_uart_request_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); struct resource *res_mem; res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (unlikely(!res_mem)) return -EINVAL; if (!request_mem_region(port->mapbase, resource_size(res_mem), "pic32_uart_mem")) return -EBUSY; port->membase = devm_ioremap(port->dev, port->mapbase, resource_size(res_mem)); if (!port->membase) { dev_err(port->dev, "Unable to map registers\n"); release_mem_region(port->mapbase, resource_size(res_mem)); return -ENOMEM; } return 0; } /* serial core request to release uart iomem */ static void pic32_uart_release_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); struct resource *res_mem; unsigned int res_size; res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (unlikely(!res_mem)) return; res_size = resource_size(res_mem); release_mem_region(port->mapbase, res_size); } /* serial core request to do any port required auto-configuration */ static void pic32_uart_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) { if (pic32_uart_request_port(port)) return; port->type = PORT_PIC32; } } /* serial core request to check that port information in serinfo are suitable */ static int pic32_uart_verify_port(struct uart_port *port, struct serial_struct *serinfo) { if (port->type != PORT_PIC32) return -EINVAL; if (port->irq != serinfo->irq) return -EINVAL; if (port->iotype != serinfo->io_type) return -EINVAL; if (port->mapbase != (unsigned long)serinfo->iomem_base) return -EINVAL; return 0; } /* serial core callbacks */ static const struct uart_ops pic32_uart_ops = { .tx_empty = pic32_uart_tx_empty, .get_mctrl = pic32_uart_get_mctrl, .set_mctrl = pic32_uart_set_mctrl, .start_tx = pic32_uart_start_tx, .stop_tx = pic32_uart_stop_tx, .stop_rx = pic32_uart_stop_rx, .break_ctl = pic32_uart_break_ctl, .startup = pic32_uart_startup, .shutdown = pic32_uart_shutdown, .set_termios = pic32_uart_set_termios, .type = pic32_uart_type, .release_port = pic32_uart_release_port, .request_port = pic32_uart_request_port, .config_port = pic32_uart_config_port, .verify_port = pic32_uart_verify_port, }; #ifdef CONFIG_SERIAL_PIC32_CONSOLE /* output given char */ static void pic32_console_putchar(struct uart_port *port, unsigned char ch) { struct pic32_sport *sport = to_pic32_sport(port); if (!(pic32_uart_readl(sport, PIC32_UART_MODE) & PIC32_UART_MODE_ON)) return; if (!(pic32_uart_readl(sport, PIC32_UART_STA) & PIC32_UART_STA_UTXEN)) return; /* wait for tx empty */ pic32_wait_deplete_txbuf(sport); pic32_uart_writel(sport, PIC32_UART_TX, ch & 0xff); } /* console core request to output given string */ static void pic32_console_write(struct console *co, const char *s, unsigned int count) { struct pic32_sport *sport = pic32_sports[co->index]; /* call uart helper to deal with \r\n */ uart_console_write(&sport->port, s, count, pic32_console_putchar); } /* console core request to setup given console, find matching uart * port and setup it. */ static int pic32_console_setup(struct console *co, char *options) { struct pic32_sport *sport; int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; int ret = 0; if (unlikely(co->index < 0 || co->index >= PIC32_MAX_UARTS)) return -ENODEV; sport = pic32_sports[co->index]; if (!sport) return -ENODEV; ret = clk_prepare_enable(sport->clk); if (ret) return ret; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); return uart_set_options(&sport->port, co, baud, parity, bits, flow); } static struct uart_driver pic32_uart_driver; static struct console pic32_console = { .name = PIC32_SDEV_NAME, .write = pic32_console_write, .device = uart_console_device, .setup = pic32_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &pic32_uart_driver, }; #define PIC32_SCONSOLE (&pic32_console) static int __init pic32_console_init(void) { register_console(&pic32_console); return 0; } console_initcall(pic32_console_init); /* * Late console initialization. */ static int __init pic32_late_console_init(void) { if (!console_is_registered(&pic32_console)) register_console(&pic32_console); return 0; } core_initcall(pic32_late_console_init); #else #define PIC32_SCONSOLE NULL #endif static struct uart_driver pic32_uart_driver = { .owner = THIS_MODULE, .driver_name = PIC32_DEV_NAME, .dev_name = PIC32_SDEV_NAME, .nr = PIC32_MAX_UARTS, .cons = PIC32_SCONSOLE, }; static int pic32_uart_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; struct pic32_sport *sport; int uart_idx = 0; struct resource *res_mem; struct uart_port *port; int ret; uart_idx = of_alias_get_id(np, "serial"); if (uart_idx < 0 || uart_idx >= PIC32_MAX_UARTS) return -EINVAL; res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res_mem) return -EINVAL; sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL); if (!sport) return -ENOMEM; sport->idx = uart_idx; sport->irq_fault = irq_of_parse_and_map(np, 0); sport->irq_rx = irq_of_parse_and_map(np, 1); sport->irq_tx = irq_of_parse_and_map(np, 2); sport->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(sport->clk)) return PTR_ERR(sport->clk); sport->dev = &pdev->dev; /* Hardware flow control: gpios * !Note: Basically, CTS is needed for reading the status. */ sport->cts_gpiod = devm_gpiod_get_optional(dev, "cts", GPIOD_IN); if (IS_ERR(sport->cts_gpiod)) return dev_err_probe(dev, PTR_ERR(sport->cts_gpiod), "error requesting CTS GPIO\n"); gpiod_set_consumer_name(sport->cts_gpiod, "CTS"); pic32_sports[uart_idx] = sport; port = &sport->port; port->iotype = UPIO_MEM; port->mapbase = res_mem->start; port->ops = &pic32_uart_ops; port->flags = UPF_BOOT_AUTOCONF; port->dev = &pdev->dev; port->fifosize = PIC32_UART_TX_FIFO_DEPTH; port->uartclk = clk_get_rate(sport->clk); port->line = uart_idx; ret = uart_add_one_port(&pic32_uart_driver, port); if (ret) { port->membase = NULL; dev_err(port->dev, "%s: uart add port error!\n", __func__); goto err; } #ifdef CONFIG_SERIAL_PIC32_CONSOLE if (uart_console_registered(port)) { /* The peripheral clock has been enabled by console_setup, * so disable it till the port is used. */ clk_disable_unprepare(sport->clk); } #endif platform_set_drvdata(pdev, port); dev_info(&pdev->dev, "%s: uart(%d) driver initialized.\n", __func__, uart_idx); return 0; err: /* automatic unroll of sport and gpios */ return ret; } static void pic32_uart_remove(struct platform_device *pdev) { struct uart_port *port = platform_get_drvdata(pdev); struct pic32_sport *sport = to_pic32_sport(port); uart_remove_one_port(&pic32_uart_driver, port); clk_disable_unprepare(sport->clk); platform_set_drvdata(pdev, NULL); pic32_sports[sport->idx] = NULL; } static const struct of_device_id pic32_serial_dt_ids[] = { { .compatible = "microchip,pic32mzda-uart" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, pic32_serial_dt_ids); static struct platform_driver pic32_uart_platform_driver = { .probe = pic32_uart_probe, .remove = pic32_uart_remove, .driver = { .name = PIC32_DEV_NAME, .of_match_table = of_match_ptr(pic32_serial_dt_ids), .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_PIC32), }, }; static int __init pic32_uart_init(void) { int ret; ret = uart_register_driver(&pic32_uart_driver); if (ret) { pr_err("failed to register %s:%d\n", pic32_uart_driver.driver_name, ret); return ret; } ret = platform_driver_register(&pic32_uart_platform_driver); if (ret) { pr_err("fail to register pic32 uart\n"); uart_unregister_driver(&pic32_uart_driver); } return ret; } arch_initcall(pic32_uart_init); static void __exit pic32_uart_exit(void) { #ifdef CONFIG_SERIAL_PIC32_CONSOLE unregister_console(&pic32_console); #endif platform_driver_unregister(&pic32_uart_platform_driver); uart_unregister_driver(&pic32_uart_driver); } module_exit(pic32_uart_exit); MODULE_AUTHOR("Sorin-Andrei Pistirica "); MODULE_DESCRIPTION("Microchip PIC32 integrated serial port driver"); MODULE_LICENSE("GPL v2");