// SPDX-License-Identifier: GPL-2.0+ /* * Driver for Atmel AT91 Serial ports * Copyright (C) 2003 Rick Bronson * * Based on drivers/char/serial_sa1100.c, by Deep Blue Solutions Ltd. * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * * DMA support added by Chip Coldwell. */ #include <linux/circ_buf.h> #include <linux/tty.h> #include <linux/ioport.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/serial.h> #include <linux/clk.h> #include <linux/clk-provider.h> #include <linux/console.h> #include <linux/sysrq.h> #include <linux/tty_flip.h> #include <linux/platform_device.h> #include <linux/of.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/atmel_pdc.h> #include <linux/uaccess.h> #include <linux/platform_data/atmel.h> #include <linux/timer.h> #include <linux/err.h> #include <linux/irq.h> #include <linux/suspend.h> #include <linux/mm.h> #include <linux/io.h> #include <asm/div64.h> #include <asm/ioctls.h> #define PDC_BUFFER_SIZE … /* Revisit: We should calculate this based on the actual port settings */ #define PDC_RX_TIMEOUT … /* The minium number of data FIFOs should be able to contain */ #define ATMEL_MIN_FIFO_SIZE … /* * These two offsets are substracted from the RX FIFO size to define the RTS * high and low thresholds */ #define ATMEL_RTS_HIGH_OFFSET … #define ATMEL_RTS_LOW_OFFSET … #include <linux/serial_core.h> #include "serial_mctrl_gpio.h" #include "atmel_serial.h" static void atmel_start_rx(struct uart_port *port); static void atmel_stop_rx(struct uart_port *port); #ifdef CONFIG_SERIAL_ATMEL_TTYAT /* Use device name ttyAT, major 204 and minor 154-169. This is necessary if we * should coexist with the 8250 driver, such as if we have an external 16C550 * UART. */ #define SERIAL_ATMEL_MAJOR … #define MINOR_START … #define ATMEL_DEVICENAME … #else /* Use device name ttyS, major 4, minor 64-68. This is the usual serial port * name, but it is legally reserved for the 8250 driver. */ #define SERIAL_ATMEL_MAJOR … #define MINOR_START … #define ATMEL_DEVICENAME … #endif #define ATMEL_ISR_PASS_LIMIT … struct atmel_dma_buffer { … }; struct atmel_uart_char { … }; /* * Be careful, the real size of the ring buffer is * sizeof(atmel_uart_char) * ATMEL_SERIAL_RINGSIZE. It means that ring buffer * can contain up to 1024 characters in PIO mode and up to 4096 characters in * DMA mode. */ #define ATMEL_SERIAL_RINGSIZE … #define ATMEL_SERIAL_RX_SIZE … /* * at91: 6 USARTs and one DBGU port (SAM9260) * samx7: 3 USARTs and 5 UARTs */ #define ATMEL_MAX_UART … /* * We wrap our port structure around the generic uart_port. */ struct atmel_uart_port { … }; static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART]; static DECLARE_BITMAP(atmel_ports_in_use, ATMEL_MAX_UART); #if defined(CONFIG_OF) static const struct of_device_id atmel_serial_dt_ids[] = …; #endif static inline struct atmel_uart_port * to_atmel_uart_port(struct uart_port *uart) { … } static inline u32 atmel_uart_readl(struct uart_port *port, u32 reg) { … } static inline void atmel_uart_writel(struct uart_port *port, u32 reg, u32 value) { … } static inline u8 atmel_uart_read_char(struct uart_port *port) { … } static inline void atmel_uart_write_char(struct uart_port *port, u8 value) { … } static inline int atmel_uart_is_half_duplex(struct uart_port *port) { … } static inline int atmel_error_rate(int desired_value, int actual_value) { … } #ifdef CONFIG_SERIAL_ATMEL_PDC static bool atmel_use_pdc_rx(struct uart_port *port) { … } static bool atmel_use_pdc_tx(struct uart_port *port) { … } #else static bool atmel_use_pdc_rx(struct uart_port *port) { return false; } static bool atmel_use_pdc_tx(struct uart_port *port) { return false; } #endif static bool atmel_use_dma_tx(struct uart_port *port) { … } static bool atmel_use_dma_rx(struct uart_port *port) { … } static bool atmel_use_fifo(struct uart_port *port) { … } static void atmel_tasklet_schedule(struct atmel_uart_port *atmel_port, struct tasklet_struct *t) { … } /* Enable or disable the rs485 support */ static int atmel_config_rs485(struct uart_port *port, struct ktermios *termios, struct serial_rs485 *rs485conf) { … } static unsigned int atmel_calc_cd(struct uart_port *port, struct serial_iso7816 *iso7816conf) { … } static unsigned int atmel_calc_fidi(struct uart_port *port, struct serial_iso7816 *iso7816conf) { … } /* Enable or disable the iso7816 support */ /* Called with interrupts disabled */ static int atmel_config_iso7816(struct uart_port *port, struct serial_iso7816 *iso7816conf) { … } /* * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty. */ static u_int atmel_tx_empty(struct uart_port *port) { … } /* * Set state of the modem control output lines */ static void atmel_set_mctrl(struct uart_port *port, u_int mctrl) { … } /* * Get state of the modem control input lines */ static u_int atmel_get_mctrl(struct uart_port *port) { … } /* * Stop transmitting. */ static void atmel_stop_tx(struct uart_port *port) { … } /* * Start transmitting. */ static void atmel_start_tx(struct uart_port *port) { … } /* * start receiving - port is in process of being opened. */ static void atmel_start_rx(struct uart_port *port) { … } /* * Stop receiving - port is in process of being closed. */ static void atmel_stop_rx(struct uart_port *port) { … } /* * Enable modem status interrupts */ static void atmel_enable_ms(struct uart_port *port) { … } /* * Disable modem status interrupts */ static void atmel_disable_ms(struct uart_port *port) { … } /* * Control the transmission of a break signal */ static void atmel_break_ctl(struct uart_port *port, int break_state) { … } /* * Stores the incoming character in the ring buffer */ static void atmel_buffer_rx_char(struct uart_port *port, unsigned int status, unsigned int ch) { … } /* * Deal with parity, framing and overrun errors. */ static void atmel_pdc_rxerr(struct uart_port *port, unsigned int status) { … } /* * Characters received (called from interrupt handler) */ static void atmel_rx_chars(struct uart_port *port) { … } /* * Transmit characters (called from tasklet with TXRDY interrupt * disabled) */ static void atmel_tx_chars(struct uart_port *port) { … } static void atmel_complete_tx_dma(void *arg) { … } static void atmel_release_tx_dma(struct uart_port *port) { … } /* * Called from tasklet with TXRDY interrupt is disabled. */ static void atmel_tx_dma(struct uart_port *port) { … } static int atmel_prepare_tx_dma(struct uart_port *port) { … } static void atmel_complete_rx_dma(void *arg) { … } static void atmel_release_rx_dma(struct uart_port *port) { … } static void atmel_rx_from_dma(struct uart_port *port) { … } static int atmel_prepare_rx_dma(struct uart_port *port) { … } static void atmel_uart_timer_callback(struct timer_list *t) { … } /* * receive interrupt handler. */ static void atmel_handle_receive(struct uart_port *port, unsigned int pending) { … } /* * transmit interrupt handler. (Transmit is IRQF_NODELAY safe) */ static void atmel_handle_transmit(struct uart_port *port, unsigned int pending) { … } /* * status flags interrupt handler. */ static void atmel_handle_status(struct uart_port *port, unsigned int pending, unsigned int status) { … } /* * Interrupt handler */ static irqreturn_t atmel_interrupt(int irq, void *dev_id) { … } static void atmel_release_tx_pdc(struct uart_port *port) { … } /* * Called from tasklet with ENDTX and TXBUFE interrupts disabled. */ static void atmel_tx_pdc(struct uart_port *port) { … } static int atmel_prepare_tx_pdc(struct uart_port *port) { … } static void atmel_rx_from_ring(struct uart_port *port) { … } static void atmel_release_rx_pdc(struct uart_port *port) { … } static void atmel_rx_from_pdc(struct uart_port *port) { … } static int atmel_prepare_rx_pdc(struct uart_port *port) { … } /* * tasklet handling tty stuff outside the interrupt handler. */ static void atmel_tasklet_rx_func(struct tasklet_struct *t) { … } static void atmel_tasklet_tx_func(struct tasklet_struct *t) { … } static void atmel_init_property(struct atmel_uart_port *atmel_port, struct platform_device *pdev) { … } static void atmel_set_ops(struct uart_port *port) { … } /* * Get ip name usart or uart */ static void atmel_get_ip_name(struct uart_port *port) { … } /* * Perform initialization and enable port for reception */ static int atmel_startup(struct uart_port *port) { … } /* * Flush any TX data submitted for DMA. Called when the TX circular * buffer is reset. */ static void atmel_flush_buffer(struct uart_port *port) { … } /* * Disable the port */ static void atmel_shutdown(struct uart_port *port) { … } /* * Power / Clock management. */ static void atmel_serial_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { … } /* * Change the port parameters */ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, const struct ktermios *old) { … } static void atmel_set_ldisc(struct uart_port *port, struct ktermios *termios) { … } /* * Return string describing the specified port */ static const char *atmel_type(struct uart_port *port) { … } /* * Release the memory region(s) being used by 'port'. */ static void atmel_release_port(struct uart_port *port) { … } /* * Request the memory region(s) being used by 'port'. */ static int atmel_request_port(struct uart_port *port) { … } /* * Configure/autoconfigure the port. */ static void atmel_config_port(struct uart_port *port, int flags) { … } /* * Verify the new serial_struct (for TIOCSSERIAL). */ static int atmel_verify_port(struct uart_port *port, struct serial_struct *ser) { … } #ifdef CONFIG_CONSOLE_POLL static int atmel_poll_get_char(struct uart_port *port) { … } static void atmel_poll_put_char(struct uart_port *port, unsigned char ch) { … } #endif static const struct uart_ops atmel_pops = …; static const struct serial_rs485 atmel_rs485_supported = …; /* * Configure the port from the platform device resource info. */ static int atmel_init_port(struct atmel_uart_port *atmel_port, struct platform_device *pdev) { … } #ifdef CONFIG_SERIAL_ATMEL_CONSOLE static void atmel_console_putchar(struct uart_port *port, unsigned char ch) { … } /* * Interrupts are disabled on entering */ static void atmel_console_write(struct console *co, const char *s, u_int count) { … } /* * If the port was already initialised (eg, by a boot loader), * try to determine the current setup. */ static void __init atmel_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits) { … } static int __init atmel_console_setup(struct console *co, char *options) { … } static struct uart_driver atmel_uart; static struct console atmel_console = …; static void atmel_serial_early_write(struct console *con, const char *s, unsigned int n) { … } static int __init atmel_early_console_setup(struct earlycon_device *device, const char *options) { … } OF_EARLYCON_DECLARE(…); OF_EARLYCON_DECLARE(…); #define ATMEL_CONSOLE_DEVICE … #else #define ATMEL_CONSOLE_DEVICE … #endif static struct uart_driver atmel_uart = …; static bool atmel_serial_clk_will_stop(void) { … } static int __maybe_unused atmel_serial_suspend(struct device *dev) { … } static int __maybe_unused atmel_serial_resume(struct device *dev) { … } static void atmel_serial_probe_fifos(struct atmel_uart_port *atmel_port, struct platform_device *pdev) { … } static int atmel_serial_probe(struct platform_device *pdev) { … } /* * Even if the driver is not modular, it makes sense to be able to * unbind a device: there can be many bound devices, and there are * situations where dynamic binding and unbinding can be useful. * * For example, a connected device can require a specific firmware update * protocol that needs bitbanging on IO lines, but use the regular serial * port in the normal case. */ static void atmel_serial_remove(struct platform_device *pdev) { … } static SIMPLE_DEV_PM_OPS(atmel_serial_pm_ops, atmel_serial_suspend, atmel_serial_resume); static struct platform_driver atmel_serial_driver = …; static int __init atmel_serial_init(void) { … } device_initcall(atmel_serial_init);
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