/* * Driver for the PSC of the Freescale MPC52xx PSCs configured as UARTs. * * FIXME According to the usermanual the status bits in the status register * are only updated when the peripherals access the FIFO and not when the * CPU access them. So since we use this bits to know when we stop writing * and reading, they may not be updated in-time and a race condition may * exists. But I haven't be able to prove this and I don't care. But if * any problem arises, it might worth checking. The TX/RX FIFO Stats * registers should be used in addition. * Update: Actually, they seem updated ... At least the bits we use. * * * Maintainer : Sylvain Munaut <tnt@246tNt.com> * * Some of the code has been inspired/copied from the 2.4 code written * by Dale Farnsworth <dfarnsworth@mvista.com>. * * Copyright (C) 2008 Freescale Semiconductor Inc. * John Rigby <jrigby@gmail.com> * Added support for MPC5121 * Copyright (C) 2006 Secret Lab Technologies Ltd. * Grant Likely <grant.likely@secretlab.ca> * Copyright (C) 2004-2006 Sylvain Munaut <tnt@246tNt.com> * Copyright (C) 2003 MontaVista, Software, 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. */ #undef DEBUG #include <linux/device.h> #include <linux/module.h> #include <linux/tty.h> #include <linux/serial.h> #include <linux/sysrq.h> #include <linux/console.h> #include <linux/delay.h> #include <linux/io.h> #include <linux/of.h> #include <linux/of_platform.h> #include <linux/clk.h> #include <asm/mpc52xx.h> #include <asm/mpc52xx_psc.h> #if defined(CONFIG_SERIAL_MPC52xx_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) #define SUPPORT_SYSRQ #endif #include <linux/serial_core.h> /* We've been assigned a range on the "Low-density serial ports" major */ #define SERIAL_PSC_MAJOR 204 #define SERIAL_PSC_MINOR 148 #define ISR_PASS_LIMIT 256 /* Max number of iteration in the interrupt */ static struct uart_port mpc52xx_uart_ports[MPC52xx_PSC_MAXNUM]; /* Rem: - We use the read_status_mask as a shadow of * psc->mpc52xx_psc_imr * - It's important that is array is all zero on start as we * use it to know if it's initialized or not ! If it's not sure * it's cleared, then a memset(...,0,...) should be added to * the console_init */ /* lookup table for matching device nodes to index numbers */ static struct device_node *mpc52xx_uart_nodes[MPC52xx_PSC_MAXNUM]; static void mpc52xx_uart_of_enumerate(void); #define PSC(port) ((struct mpc52xx_psc __iomem *)((port)->membase)) /* Forward declaration of the interruption handling routine */ static irqreturn_t mpc52xx_uart_int(int irq, void *dev_id); static irqreturn_t mpc5xxx_uart_process_int(struct uart_port *port); /* Simple macro to test if a port is console or not. This one is taken * for serial_core.c and maybe should be moved to serial_core.h ? */ #ifdef CONFIG_SERIAL_CORE_CONSOLE #define uart_console(port) \ ((port)->cons && (port)->cons->index == (port)->line) #else #define uart_console(port) (0) #endif /* ======================================================================== */ /* PSC fifo operations for isolating differences between 52xx and 512x */ /* ======================================================================== */ struct psc_ops { void (*fifo_init)(struct uart_port *port); int (*raw_rx_rdy)(struct uart_port *port); int (*raw_tx_rdy)(struct uart_port *port); int (*rx_rdy)(struct uart_port *port); int (*tx_rdy)(struct uart_port *port); int (*tx_empty)(struct uart_port *port); void (*stop_rx)(struct uart_port *port); void (*start_tx)(struct uart_port *port); void (*stop_tx)(struct uart_port *port); void (*rx_clr_irq)(struct uart_port *port); void (*tx_clr_irq)(struct uart_port *port); void (*write_char)(struct uart_port *port, unsigned char c); unsigned char (*read_char)(struct uart_port *port); void (*cw_disable_ints)(struct uart_port *port); void (*cw_restore_ints)(struct uart_port *port); unsigned int (*set_baudrate)(struct uart_port *port, struct ktermios *new, struct ktermios *old); int (*clock)(struct uart_port *port, int enable); int (*fifoc_init)(void); void (*fifoc_uninit)(void); void (*get_irq)(struct uart_port *, struct device_node *); irqreturn_t (*handle_irq)(struct uart_port *port); }; /* setting the prescaler and divisor reg is common for all chips */ static inline void mpc52xx_set_divisor(struct mpc52xx_psc __iomem *psc, u16 prescaler, unsigned int divisor) { /* select prescaler */ out_be16(&psc->mpc52xx_psc_clock_select, prescaler); out_8(&psc->ctur, divisor >> 8); out_8(&psc->ctlr, divisor & 0xff); } #ifdef CONFIG_PPC_MPC52xx #define FIFO_52xx(port) ((struct mpc52xx_psc_fifo __iomem *)(PSC(port)+1)) static void mpc52xx_psc_fifo_init(struct uart_port *port) { struct mpc52xx_psc __iomem *psc = PSC(port); struct mpc52xx_psc_fifo __iomem *fifo = FIFO_52xx(port); out_8(&fifo->rfcntl, 0x00); out_be16(&fifo->rfalarm, 0x1ff); out_8(&fifo->tfcntl, 0x07); out_be16(&fifo->tfalarm, 0x80); port->read_status_mask |= MPC52xx_PSC_IMR_RXRDY | MPC52xx_PSC_IMR_TXRDY; out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask); } static int mpc52xx_psc_raw_rx_rdy(struct uart_port *port) { return in_be16(&PSC(port)->mpc52xx_psc_status) & MPC52xx_PSC_SR_RXRDY; } static int mpc52xx_psc_raw_tx_rdy(struct uart_port *port) { return in_be16(&PSC(port)->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXRDY; } static int mpc52xx_psc_rx_rdy(struct uart_port *port) { return in_be16(&PSC(port)->mpc52xx_psc_isr) & port->read_status_mask & MPC52xx_PSC_IMR_RXRDY; } static int mpc52xx_psc_tx_rdy(struct uart_port *port) { return in_be16(&PSC(port)->mpc52xx_psc_isr) & port->read_status_mask & MPC52xx_PSC_IMR_TXRDY; } static int mpc52xx_psc_tx_empty(struct uart_port *port) { return in_be16(&PSC(port)->mpc52xx_psc_status) & MPC52xx_PSC_SR_TXEMP; } static void mpc52xx_psc_start_tx(struct uart_port *port) { port->read_status_mask |= MPC52xx_PSC_IMR_TXRDY; out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask); } static void mpc52xx_psc_stop_tx(struct uart_port *port) { port->read_status_mask &= ~MPC52xx_PSC_IMR_TXRDY; out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask); } static void mpc52xx_psc_stop_rx(struct uart_port *port) { port->read_status_mask &= ~MPC52xx_PSC_IMR_RXRDY; out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask); } static void mpc52xx_psc_rx_clr_irq(struct uart_port *port) { } static void mpc52xx_psc_tx_clr_irq(struct uart_port *port) { } static void mpc52xx_psc_write_char(struct uart_port *port, unsigned char c) { out_8(&PSC(port)->mpc52xx_psc_buffer_8, c); } static unsigned char mpc52xx_psc_read_char(struct uart_port *port) { return in_8(&PSC(port)->mpc52xx_psc_buffer_8); } static void mpc52xx_psc_cw_disable_ints(struct uart_port *port) { out_be16(&PSC(port)->mpc52xx_psc_imr, 0); } static void mpc52xx_psc_cw_restore_ints(struct uart_port *port) { out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask); } static unsigned int mpc5200_psc_set_baudrate(struct uart_port *port, struct ktermios *new, struct ktermios *old) { unsigned int baud; unsigned int divisor; /* The 5200 has a fixed /32 prescaler, uartclk contains the ipb freq */ baud = uart_get_baud_rate(port, new, old, port->uartclk / (32 * 0xffff) + 1, port->uartclk / 32); divisor = (port->uartclk + 16 * baud) / (32 * baud); /* enable the /32 prescaler and set the divisor */ mpc52xx_set_divisor(PSC(port), 0xdd00, divisor); return baud; } static unsigned int mpc5200b_psc_set_baudrate(struct uart_port *port, struct ktermios *new, struct ktermios *old) { unsigned int baud; unsigned int divisor; u16 prescaler; /* The 5200B has a selectable /4 or /32 prescaler, uartclk contains the * ipb freq */ baud = uart_get_baud_rate(port, new, old, port->uartclk / (32 * 0xffff) + 1, port->uartclk / 4); divisor = (port->uartclk + 2 * baud) / (4 * baud); /* select the proper prescaler and set the divisor */ if (divisor > 0xffff) { divisor = (divisor + 4) / 8; prescaler = 0xdd00; /* /32 */ } else prescaler = 0xff00; /* /4 */ mpc52xx_set_divisor(PSC(port), prescaler, divisor); return baud; } static void mpc52xx_psc_get_irq(struct uart_port *port, struct device_node *np) { port->irqflags = IRQF_DISABLED; port->irq = irq_of_parse_and_map(np, 0); } /* 52xx specific interrupt handler. The caller holds the port lock */ static irqreturn_t mpc52xx_psc_handle_irq(struct uart_port *port) { return mpc5xxx_uart_process_int(port); } static struct psc_ops mpc52xx_psc_ops = { .fifo_init = mpc52xx_psc_fifo_init, .raw_rx_rdy = mpc52xx_psc_raw_rx_rdy, .raw_tx_rdy = mpc52xx_psc_raw_tx_rdy, .rx_rdy = mpc52xx_psc_rx_rdy, .tx_rdy = mpc52xx_psc_tx_rdy, .tx_empty = mpc52xx_psc_tx_empty, .stop_rx = mpc52xx_psc_stop_rx, .start_tx = mpc52xx_psc_start_tx, .stop_tx = mpc52xx_psc_stop_tx, .rx_clr_irq = mpc52xx_psc_rx_clr_irq, .tx_clr_irq = mpc52xx_psc_tx_clr_irq, .write_char = mpc52xx_psc_write_char, .read_char = mpc52xx_psc_read_char, .cw_disable_ints = mpc52xx_psc_cw_disable_ints, .cw_restore_ints = mpc52xx_psc_cw_restore_ints, .set_baudrate = mpc5200_psc_set_baudrate, .get_irq = mpc52xx_psc_get_irq, .handle_irq = mpc52xx_psc_handle_irq, }; static struct psc_ops mpc5200b_psc_ops = { .fifo_init = mpc52xx_psc_fifo_init, .raw_rx_rdy = mpc52xx_psc_raw_rx_rdy, .raw_tx_rdy = mpc52xx_psc_raw_tx_rdy, .rx_rdy = mpc52xx_psc_rx_rdy, .tx_rdy = mpc52xx_psc_tx_rdy, .tx_empty = mpc52xx_psc_tx_empty, .stop_rx = mpc52xx_psc_stop_rx, .start_tx = mpc52xx_psc_start_tx, .stop_tx = mpc52xx_psc_stop_tx, .rx_clr_irq = mpc52xx_psc_rx_clr_irq, .tx_clr_irq = mpc52xx_psc_tx_clr_irq, .write_char = mpc52xx_psc_write_char, .read_char = mpc52xx_psc_read_char, .cw_disable_ints = mpc52xx_psc_cw_disable_ints, .cw_restore_ints = mpc52xx_psc_cw_restore_ints, .set_baudrate = mpc5200b_psc_set_baudrate, .get_irq = mpc52xx_psc_get_irq, .handle_irq = mpc52xx_psc_handle_irq, }; #endif /* CONFIG_MPC52xx */ #ifdef CONFIG_PPC_MPC512x #define FIFO_512x(port) ((struct mpc512x_psc_fifo __iomem *)(PSC(port)+1)) /* PSC FIFO Controller for mpc512x */ struct psc_fifoc { u32 fifoc_cmd; u32 fifoc_int; u32 fifoc_dma; u32 fifoc_axe; u32 fifoc_debug; }; static struct psc_fifoc __iomem *psc_fifoc; static unsigned int psc_fifoc_irq; static void mpc512x_psc_fifo_init(struct uart_port *port) { /* /32 prescaler */ out_be16(&PSC(port)->mpc52xx_psc_clock_select, 0xdd00); out_be32(&FIFO_512x(port)->txcmd, MPC512x_PSC_FIFO_RESET_SLICE); out_be32(&FIFO_512x(port)->txcmd, MPC512x_PSC_FIFO_ENABLE_SLICE); out_be32(&FIFO_512x(port)->txalarm, 1); out_be32(&FIFO_512x(port)->tximr, 0); out_be32(&FIFO_512x(port)->rxcmd, MPC512x_PSC_FIFO_RESET_SLICE); out_be32(&FIFO_512x(port)->rxcmd, MPC512x_PSC_FIFO_ENABLE_SLICE); out_be32(&FIFO_512x(port)->rxalarm, 1); out_be32(&FIFO_512x(port)->rximr, 0); out_be32(&FIFO_512x(port)->tximr, MPC512x_PSC_FIFO_ALARM); out_be32(&FIFO_512x(port)->rximr, MPC512x_PSC_FIFO_ALARM); } static int mpc512x_psc_raw_rx_rdy(struct uart_port *port) { return !(in_be32(&FIFO_512x(port)->rxsr) & MPC512x_PSC_FIFO_EMPTY); } static int mpc512x_psc_raw_tx_rdy(struct uart_port *port) { return !(in_be32(&FIFO_512x(port)->txsr) & MPC512x_PSC_FIFO_FULL); } static int mpc512x_psc_rx_rdy(struct uart_port *port) { return in_be32(&FIFO_512x(port)->rxsr) & in_be32(&FIFO_512x(port)->rximr) & MPC512x_PSC_FIFO_ALARM; } static int mpc512x_psc_tx_rdy(struct uart_port *port) { return in_be32(&FIFO_512x(port)->txsr) & in_be32(&FIFO_512x(port)->tximr) & MPC512x_PSC_FIFO_ALARM; } static int mpc512x_psc_tx_empty(struct uart_port *port) { return in_be32(&FIFO_512x(port)->txsr) & MPC512x_PSC_FIFO_EMPTY; } static void mpc512x_psc_stop_rx(struct uart_port *port) { unsigned long rx_fifo_imr; rx_fifo_imr = in_be32(&FIFO_512x(port)->rximr); rx_fifo_imr &= ~MPC512x_PSC_FIFO_ALARM; out_be32(&FIFO_512x(port)->rximr, rx_fifo_imr); } static void mpc512x_psc_start_tx(struct uart_port *port) { unsigned long tx_fifo_imr; tx_fifo_imr = in_be32(&FIFO_512x(port)->tximr); tx_fifo_imr |= MPC512x_PSC_FIFO_ALARM; out_be32(&FIFO_512x(port)->tximr, tx_fifo_imr); } static void mpc512x_psc_stop_tx(struct uart_port *port) { unsigned long tx_fifo_imr; tx_fifo_imr = in_be32(&FIFO_512x(port)->tximr); tx_fifo_imr &= ~MPC512x_PSC_FIFO_ALARM; out_be32(&FIFO_512x(port)->tximr, tx_fifo_imr); } static void mpc512x_psc_rx_clr_irq(struct uart_port *port) { out_be32(&FIFO_512x(port)->rxisr, in_be32(&FIFO_512x(port)->rxisr)); } static void mpc512x_psc_tx_clr_irq(struct uart_port *port) { out_be32(&FIFO_512x(port)->txisr, in_be32(&FIFO_512x(port)->txisr)); } static void mpc512x_psc_write_char(struct uart_port *port, unsigned char c) { out_8(&FIFO_512x(port)->txdata_8, c); } static unsigned char mpc512x_psc_read_char(struct uart_port *port) { return in_8(&FIFO_512x(port)->rxdata_8); } static void mpc512x_psc_cw_disable_ints(struct uart_port *port) { port->read_status_mask = in_be32(&FIFO_512x(port)->tximr) << 16 | in_be32(&FIFO_512x(port)->rximr); out_be32(&FIFO_512x(port)->tximr, 0); out_be32(&FIFO_512x(port)->rximr, 0); } static void mpc512x_psc_cw_restore_ints(struct uart_port *port) { out_be32(&FIFO_512x(port)->tximr, (port->read_status_mask >> 16) & 0x7f); out_be32(&FIFO_512x(port)->rximr, port->read_status_mask & 0x7f); } static unsigned int mpc512x_psc_set_baudrate(struct uart_port *port, struct ktermios *new, struct ktermios *old) { unsigned int baud; unsigned int divisor; /* * The "MPC5121e Microcontroller Reference Manual, Rev. 3" says on * pg. 30-10 that the chip supports a /32 and a /10 prescaler. * Furthermore, it states that "After reset, the prescaler by 10 * for the UART mode is selected", but the reset register value is * 0x0000 which means a /32 prescaler. This is wrong. * * In reality using /32 prescaler doesn't work, as it is not supported! * Use /16 or /10 prescaler, see "MPC5121e Hardware Design Guide", * Chapter 4.1 PSC in UART Mode. * Calculate with a /16 prescaler here. */ /* uartclk contains the ips freq */ baud = uart_get_baud_rate(port, new, old, port->uartclk / (16 * 0xffff) + 1, port->uartclk / 16); divisor = (port->uartclk + 8 * baud) / (16 * baud); /* enable the /16 prescaler and set the divisor */ mpc52xx_set_divisor(PSC(port), 0xdd00, divisor); return baud; } /* Init PSC FIFO Controller */ static int __init mpc512x_psc_fifoc_init(void) { struct device_node *np; np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-psc-fifo"); if (!np) { pr_err("%s: Can't find FIFOC node\n", __func__); return -ENODEV; } psc_fifoc = of_iomap(np, 0); if (!psc_fifoc) { pr_err("%s: Can't map FIFOC\n", __func__); of_node_put(np); return -ENODEV; } psc_fifoc_irq = irq_of_parse_and_map(np, 0); of_node_put(np); if (psc_fifoc_irq == NO_IRQ) { pr_err("%s: Can't get FIFOC irq\n", __func__); iounmap(psc_fifoc); return -ENODEV; } return 0; } static void __exit mpc512x_psc_fifoc_uninit(void) { iounmap(psc_fifoc); } /* 512x specific interrupt handler. The caller holds the port lock */ static irqreturn_t mpc512x_psc_handle_irq(struct uart_port *port) { unsigned long fifoc_int; int psc_num; /* Read pending PSC FIFOC interrupts */ fifoc_int = in_be32(&psc_fifoc->fifoc_int); /* Check if it is an interrupt for this port */ psc_num = (port->mapbase & 0xf00) >> 8; if (test_bit(psc_num, &fifoc_int) || test_bit(psc_num + 16, &fifoc_int)) return mpc5xxx_uart_process_int(port); return IRQ_NONE; } static int mpc512x_psc_clock(struct uart_port *port, int enable) { struct clk *psc_clk; int psc_num; char clk_name[10]; if (uart_console(port)) return 0; psc_num = (port->mapbase & 0xf00) >> 8; snprintf(clk_name, sizeof(clk_name), "psc%d_clk", psc_num); psc_clk = clk_get(port->dev, clk_name); if (IS_ERR(psc_clk)) { dev_err(port->dev, "Failed to get PSC clock entry!\n"); return -ENODEV; } dev_dbg(port->dev, "%s %sable\n", clk_name, enable ? "en" : "dis"); if (enable) clk_enable(psc_clk); else clk_disable(psc_clk); return 0; } static void mpc512x_psc_get_irq(struct uart_port *port, struct device_node *np) { port->irqflags = IRQF_SHARED; port->irq = psc_fifoc_irq; } static struct psc_ops mpc512x_psc_ops = { .fifo_init = mpc512x_psc_fifo_init, .raw_rx_rdy = mpc512x_psc_raw_rx_rdy, .raw_tx_rdy = mpc512x_psc_raw_tx_rdy, .rx_rdy = mpc512x_psc_rx_rdy, .tx_rdy = mpc512x_psc_tx_rdy, .tx_empty = mpc512x_psc_tx_empty, .stop_rx = mpc512x_psc_stop_rx, .start_tx = mpc512x_psc_start_tx, .stop_tx = mpc512x_psc_stop_tx, .rx_clr_irq = mpc512x_psc_rx_clr_irq, .tx_clr_irq = mpc512x_psc_tx_clr_irq, .write_char = mpc512x_psc_write_char, .read_char = mpc512x_psc_read_char, .cw_disable_ints = mpc512x_psc_cw_disable_ints, .cw_restore_ints = mpc512x_psc_cw_restore_ints, .set_baudrate = mpc512x_psc_set_baudrate, .clock = mpc512x_psc_clock, .fifoc_init = mpc512x_psc_fifoc_init, .fifoc_uninit = mpc512x_psc_fifoc_uninit, .get_irq = mpc512x_psc_get_irq, .handle_irq = mpc512x_psc_handle_irq, }; #endif static struct psc_ops *psc_ops; /* ======================================================================== */ /* UART operations */ /* ======================================================================== */ static unsigned int mpc52xx_uart_tx_empty(struct uart_port *port) { return psc_ops->tx_empty(port) ? TIOCSER_TEMT : 0; } static void mpc52xx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) { if (mctrl & TIOCM_RTS) out_8(&PSC(port)->op1, MPC52xx_PSC_OP_RTS); else out_8(&PSC(port)->op0, MPC52xx_PSC_OP_RTS); } static unsigned int mpc52xx_uart_get_mctrl(struct uart_port *port) { unsigned int ret = TIOCM_DSR; u8 status = in_8(&PSC(port)->mpc52xx_psc_ipcr); if (!(status & MPC52xx_PSC_CTS)) ret |= TIOCM_CTS; if (!(status & MPC52xx_PSC_DCD)) ret |= TIOCM_CAR; return ret; } static void mpc52xx_uart_stop_tx(struct uart_port *port) { /* port->lock taken by caller */ psc_ops->stop_tx(port); } static void mpc52xx_uart_start_tx(struct uart_port *port) { /* port->lock taken by caller */ psc_ops->start_tx(port); } static void mpc52xx_uart_send_xchar(struct uart_port *port, char ch) { unsigned long flags; spin_lock_irqsave(&port->lock, flags); port->x_char = ch; if (ch) { /* Make sure tx interrupts are on */ /* Truly necessary ??? They should be anyway */ psc_ops->start_tx(port); } spin_unlock_irqrestore(&port->lock, flags); } static void mpc52xx_uart_stop_rx(struct uart_port *port) { /* port->lock taken by caller */ psc_ops->stop_rx(port); } static void mpc52xx_uart_enable_ms(struct uart_port *port) { struct mpc52xx_psc __iomem *psc = PSC(port); /* clear D_*-bits by reading them */ in_8(&psc->mpc52xx_psc_ipcr); /* enable CTS and DCD as IPC interrupts */ out_8(&psc->mpc52xx_psc_acr, MPC52xx_PSC_IEC_CTS | MPC52xx_PSC_IEC_DCD); port->read_status_mask |= MPC52xx_PSC_IMR_IPC; out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask); } static void mpc52xx_uart_break_ctl(struct uart_port *port, int ctl) { unsigned long flags; spin_lock_irqsave(&port->lock, flags); if (ctl == -1) out_8(&PSC(port)->command, MPC52xx_PSC_START_BRK); else out_8(&PSC(port)->command, MPC52xx_PSC_STOP_BRK); spin_unlock_irqrestore(&port->lock, flags); } static int mpc52xx_uart_startup(struct uart_port *port) { struct mpc52xx_psc __iomem *psc = PSC(port); int ret; if (psc_ops->clock) { ret = psc_ops->clock(port, 1); if (ret) return ret; } /* Request IRQ */ ret = request_irq(port->irq, mpc52xx_uart_int, port->irqflags, "mpc52xx_psc_uart", port); if (ret) return ret; /* Reset/activate the port, clear and enable interrupts */ out_8(&psc->command, MPC52xx_PSC_RST_RX); out_8(&psc->command, MPC52xx_PSC_RST_TX); out_be32(&psc->sicr, 0); /* UART mode DCD ignored */ psc_ops->fifo_init(port); out_8(&psc->command, MPC52xx_PSC_TX_ENABLE); out_8(&psc->command, MPC52xx_PSC_RX_ENABLE); return 0; } static void mpc52xx_uart_shutdown(struct uart_port *port) { struct mpc52xx_psc __iomem *psc = PSC(port); /* Shut down the port. Leave TX active if on a console port */ out_8(&psc->command, MPC52xx_PSC_RST_RX); if (!uart_console(port)) out_8(&psc->command, MPC52xx_PSC_RST_TX); port->read_status_mask = 0; out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask); if (psc_ops->clock) psc_ops->clock(port, 0); /* Release interrupt */ free_irq(port->irq, port); } static void mpc52xx_uart_set_termios(struct uart_port *port, struct ktermios *new, struct ktermios *old) { struct mpc52xx_psc __iomem *psc = PSC(port); unsigned long flags; unsigned char mr1, mr2; unsigned int j; unsigned int baud; /* Prepare what we're gonna write */ mr1 = 0; switch (new->c_cflag & CSIZE) { case CS5: mr1 |= MPC52xx_PSC_MODE_5_BITS; break; case CS6: mr1 |= MPC52xx_PSC_MODE_6_BITS; break; case CS7: mr1 |= MPC52xx_PSC_MODE_7_BITS; break; case CS8: default: mr1 |= MPC52xx_PSC_MODE_8_BITS; } if (new->c_cflag & PARENB) { mr1 |= (new->c_cflag & PARODD) ? MPC52xx_PSC_MODE_PARODD : MPC52xx_PSC_MODE_PAREVEN; } else mr1 |= MPC52xx_PSC_MODE_PARNONE; mr2 = 0; if (new->c_cflag & CSTOPB) mr2 |= MPC52xx_PSC_MODE_TWO_STOP; else mr2 |= ((new->c_cflag & CSIZE) == CS5) ? MPC52xx_PSC_MODE_ONE_STOP_5_BITS : MPC52xx_PSC_MODE_ONE_STOP; if (new->c_cflag & CRTSCTS) { mr1 |= MPC52xx_PSC_MODE_RXRTS; mr2 |= MPC52xx_PSC_MODE_TXCTS; } /* Get the lock */ spin_lock_irqsave(&port->lock, flags); /* Do our best to flush TX & RX, so we don't lose anything */ /* But we don't wait indefinitely ! */ j = 5000000; /* Maximum wait */ /* FIXME Can't receive chars since set_termios might be called at early * boot for the console, all stuff is not yet ready to receive at that * time and that just makes the kernel oops */ /* while (j-- && mpc52xx_uart_int_rx_chars(port)); */ while (!mpc52xx_uart_tx_empty(port) && --j) udelay(1); if (!j) printk(KERN_ERR "mpc52xx_uart.c: " "Unable to flush RX & TX fifos in-time in set_termios." "Some chars may have been lost.\n"); /* Reset the TX & RX */ out_8(&psc->command, MPC52xx_PSC_RST_RX); out_8(&psc->command, MPC52xx_PSC_RST_TX); /* Send new mode settings */ out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1); out_8(&psc->mode, mr1); out_8(&psc->mode, mr2); baud = psc_ops->set_baudrate(port, new, old); /* Update the per-port timeout */ uart_update_timeout(port, new->c_cflag, baud); if (UART_ENABLE_MS(port, new->c_cflag)) mpc52xx_uart_enable_ms(port); /* Reenable TX & RX */ out_8(&psc->command, MPC52xx_PSC_TX_ENABLE); out_8(&psc->command, MPC52xx_PSC_RX_ENABLE); /* We're all set, release the lock */ spin_unlock_irqrestore(&port->lock, flags); } static const char * mpc52xx_uart_type(struct uart_port *port) { /* * We keep using PORT_MPC52xx for historic reasons although it applies * for MPC512x, too, but print "MPC5xxx" to not irritate users */ return port->type == PORT_MPC52xx ? "MPC5xxx PSC" : NULL; } static void mpc52xx_uart_release_port(struct uart_port *port) { /* remapped by us ? */ if (port->flags & UPF_IOREMAP) { iounmap(port->membase); port->membase = NULL; } release_mem_region(port->mapbase, sizeof(struct mpc52xx_psc)); } static int mpc52xx_uart_request_port(struct uart_port *port) { int err; if (port->flags & UPF_IOREMAP) /* Need to remap ? */ port->membase = ioremap(port->mapbase, sizeof(struct mpc52xx_psc)); if (!port->membase) return -EINVAL; err = request_mem_region(port->mapbase, sizeof(struct mpc52xx_psc), "mpc52xx_psc_uart") != NULL ? 0 : -EBUSY; if (err && (port->flags & UPF_IOREMAP)) { iounmap(port->membase); port->membase = NULL; } return err; } static void mpc52xx_uart_config_port(struct uart_port *port, int flags) { if ((flags & UART_CONFIG_TYPE) && (mpc52xx_uart_request_port(port) == 0)) port->type = PORT_MPC52xx; } static int mpc52xx_uart_verify_port(struct uart_port *port, struct serial_struct *ser) { if (ser->type != PORT_UNKNOWN && ser->type != PORT_MPC52xx) return -EINVAL; if ((ser->irq != port->irq) || (ser->io_type != UPIO_MEM) || (ser->baud_base != port->uartclk) || (ser->iomem_base != (void *)port->mapbase) || (ser->hub6 != 0)) return -EINVAL; return 0; } static struct uart_ops mpc52xx_uart_ops = { .tx_empty = mpc52xx_uart_tx_empty, .set_mctrl = mpc52xx_uart_set_mctrl, .get_mctrl = mpc52xx_uart_get_mctrl, .stop_tx = mpc52xx_uart_stop_tx, .start_tx = mpc52xx_uart_start_tx, .send_xchar = mpc52xx_uart_send_xchar, .stop_rx = mpc52xx_uart_stop_rx, .enable_ms = mpc52xx_uart_enable_ms, .break_ctl = mpc52xx_uart_break_ctl, .startup = mpc52xx_uart_startup, .shutdown = mpc52xx_uart_shutdown, .set_termios = mpc52xx_uart_set_termios, /* .pm = mpc52xx_uart_pm, Not supported yet */ /* .set_wake = mpc52xx_uart_set_wake, Not supported yet */ .type = mpc52xx_uart_type, .release_port = mpc52xx_uart_release_port, .request_port = mpc52xx_uart_request_port, .config_port = mpc52xx_uart_config_port, .verify_port = mpc52xx_uart_verify_port }; /* ======================================================================== */ /* Interrupt handling */ /* ======================================================================== */ static inline int mpc52xx_uart_int_rx_chars(struct uart_port *port) { struct tty_struct *tty = port->state->port.tty; unsigned char ch, flag; unsigned short status; /* While we can read, do so ! */ while (psc_ops->raw_rx_rdy(port)) { /* Get the char */ ch = psc_ops->read_char(port); /* Handle sysreq char */ #ifdef SUPPORT_SYSRQ if (uart_handle_sysrq_char(port, ch)) { port->sysrq = 0; continue; } #endif /* Store it */ flag = TTY_NORMAL; port->icount.rx++; status = in_be16(&PSC(port)->mpc52xx_psc_status); if (status & (MPC52xx_PSC_SR_PE | MPC52xx_PSC_SR_FE | MPC52xx_PSC_SR_RB)) { if (status & MPC52xx_PSC_SR_RB) { flag = TTY_BREAK; uart_handle_break(port); port->icount.brk++; } else if (status & MPC52xx_PSC_SR_PE) { flag = TTY_PARITY; port->icount.parity++; } else if (status & MPC52xx_PSC_SR_FE) { flag = TTY_FRAME; port->icount.frame++; } /* Clear error condition */ out_8(&PSC(port)->command, MPC52xx_PSC_RST_ERR_STAT); } tty_insert_flip_char(tty, ch, flag); if (status & MPC52xx_PSC_SR_OE) { /* * Overrun is special, since it's * reported immediately, and doesn't * affect the current character */ tty_insert_flip_char(tty, 0, TTY_OVERRUN); port->icount.overrun++; } } spin_unlock(&port->lock); tty_flip_buffer_push(tty); spin_lock(&port->lock); return psc_ops->raw_rx_rdy(port); } static inline int mpc52xx_uart_int_tx_chars(struct uart_port *port) { struct circ_buf *xmit = &port->state->xmit; /* Process out of band chars */ if (port->x_char) { psc_ops->write_char(port, port->x_char); port->icount.tx++; port->x_char = 0; return 1; } /* Nothing to do ? */ if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { mpc52xx_uart_stop_tx(port); return 0; } /* Send chars */ while (psc_ops->raw_tx_rdy(port)) { psc_ops->write_char(port, xmit->buf[xmit->tail]); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; if (uart_circ_empty(xmit)) break; } /* Wake up */ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); /* Maybe we're done after all */ if (uart_circ_empty(xmit)) { mpc52xx_uart_stop_tx(port); return 0; } return 1; } static irqreturn_t mpc5xxx_uart_process_int(struct uart_port *port) { unsigned long pass = ISR_PASS_LIMIT; unsigned int keepgoing; u8 status; /* While we have stuff to do, we continue */ do { /* If we don't find anything to do, we stop */ keepgoing = 0; psc_ops->rx_clr_irq(port); if (psc_ops->rx_rdy(port)) keepgoing |= mpc52xx_uart_int_rx_chars(port); psc_ops->tx_clr_irq(port); if (psc_ops->tx_rdy(port)) keepgoing |= mpc52xx_uart_int_tx_chars(port); status = in_8(&PSC(port)->mpc52xx_psc_ipcr); if (status & MPC52xx_PSC_D_DCD) uart_handle_dcd_change(port, !(status & MPC52xx_PSC_DCD)); if (status & MPC52xx_PSC_D_CTS) uart_handle_cts_change(port, !(status & MPC52xx_PSC_CTS)); /* Limit number of iteration */ if (!(--pass)) keepgoing = 0; } while (keepgoing); return IRQ_HANDLED; } static irqreturn_t mpc52xx_uart_int(int irq, void *dev_id) { struct uart_port *port = dev_id; irqreturn_t ret; spin_lock(&port->lock); ret = psc_ops->handle_irq(port); spin_unlock(&port->lock); return ret; } /* ======================================================================== */ /* Console ( if applicable ) */ /* ======================================================================== */ #ifdef CONFIG_SERIAL_MPC52xx_CONSOLE static void __init mpc52xx_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits, int *flow) { struct mpc52xx_psc __iomem *psc = PSC(port); unsigned char mr1; pr_debug("mpc52xx_console_get_options(port=%p)\n", port); /* Read the mode registers */ out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1); mr1 = in_8(&psc->mode); /* CT{U,L}R are write-only ! */ *baud = CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD; /* Parse them */ switch (mr1 & MPC52xx_PSC_MODE_BITS_MASK) { case MPC52xx_PSC_MODE_5_BITS: *bits = 5; break; case MPC52xx_PSC_MODE_6_BITS: *bits = 6; break; case MPC52xx_PSC_MODE_7_BITS: *bits = 7; break; case MPC52xx_PSC_MODE_8_BITS: default: *bits = 8; } if (mr1 & MPC52xx_PSC_MODE_PARNONE) *parity = 'n'; else *parity = mr1 & MPC52xx_PSC_MODE_PARODD ? 'o' : 'e'; } static void mpc52xx_console_write(struct console *co, const char *s, unsigned int count) { struct uart_port *port = &mpc52xx_uart_ports[co->index]; unsigned int i, j; /* Disable interrupts */ psc_ops->cw_disable_ints(port); /* Wait the TX buffer to be empty */ j = 5000000; /* Maximum wait */ while (!mpc52xx_uart_tx_empty(port) && --j) udelay(1); /* Write all the chars */ for (i = 0; i < count; i++, s++) { /* Line return handling */ if (*s == '\n') psc_ops->write_char(port, '\r'); /* Send the char */ psc_ops->write_char(port, *s); /* Wait the TX buffer to be empty */ j = 20000; /* Maximum wait */ while (!mpc52xx_uart_tx_empty(port) && --j) udelay(1); } /* Restore interrupt state */ psc_ops->cw_restore_ints(port); } static int __init mpc52xx_console_setup(struct console *co, char *options) { struct uart_port *port = &mpc52xx_uart_ports[co->index]; struct device_node *np = mpc52xx_uart_nodes[co->index]; unsigned int uartclk; struct resource res; int ret; int baud = CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD; int bits = 8; int parity = 'n'; int flow = 'n'; pr_debug("mpc52xx_console_setup co=%p, co->index=%i, options=%s\n", co, co->index, options); if ((co->index < 0) || (co->index >= MPC52xx_PSC_MAXNUM)) { pr_debug("PSC%x out of range\n", co->index); return -EINVAL; } if (!np) { pr_debug("PSC%x not found in device tree\n", co->index); return -EINVAL; } pr_debug("Console on ttyPSC%x is %s\n", co->index, mpc52xx_uart_nodes[co->index]->full_name); /* Fetch register locations */ ret = of_address_to_resource(np, 0, &res); if (ret) { pr_debug("Could not get resources for PSC%x\n", co->index); return ret; } uartclk = mpc5xxx_get_bus_frequency(np); if (uartclk == 0) { pr_debug("Could not find uart clock frequency!\n"); return -EINVAL; } /* Basic port init. Needed since we use some uart_??? func before * real init for early access */ spin_lock_init(&port->lock); port->uartclk = uartclk; port->ops = &mpc52xx_uart_ops; port->mapbase = res.start; port->membase = ioremap(res.start, sizeof(struct mpc52xx_psc)); port->irq = irq_of_parse_and_map(np, 0); if (port->membase == NULL) return -EINVAL; pr_debug("mpc52xx-psc uart at %p, mapped to %p, irq=%x, freq=%i\n", (void *)port->mapbase, port->membase, port->irq, port->uartclk); /* Setup the port parameters accoding to options */ if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else mpc52xx_console_get_options(port, &baud, &parity, &bits, &flow); pr_debug("Setting console parameters: %i %i%c1 flow=%c\n", baud, bits, parity, flow); return uart_set_options(port, co, baud, parity, bits, flow); } static struct uart_driver mpc52xx_uart_driver; static struct console mpc52xx_console = { .name = "ttyPSC", .write = mpc52xx_console_write, .device = uart_console_device, .setup = mpc52xx_console_setup, .flags = CON_PRINTBUFFER, .index = -1, /* Specified on the cmdline (e.g. console=ttyPSC0) */ .data = &mpc52xx_uart_driver, }; static int __init mpc52xx_console_init(void) { mpc52xx_uart_of_enumerate(); register_console(&mpc52xx_console); return 0; } console_initcall(mpc52xx_console_init); #define MPC52xx_PSC_CONSOLE &mpc52xx_console #else #define MPC52xx_PSC_CONSOLE NULL #endif /* ======================================================================== */ /* UART Driver */ /* ======================================================================== */ static struct uart_driver mpc52xx_uart_driver = { .driver_name = "mpc52xx_psc_uart", .dev_name = "ttyPSC", .major = SERIAL_PSC_MAJOR, .minor = SERIAL_PSC_MINOR, .nr = MPC52xx_PSC_MAXNUM, .cons = MPC52xx_PSC_CONSOLE, }; /* ======================================================================== */ /* OF Platform Driver */ /* ======================================================================== */ static struct of_device_id mpc52xx_uart_of_match[] = { #ifdef CONFIG_PPC_MPC52xx { .compatible = "fsl,mpc5200b-psc-uart", .data = &mpc5200b_psc_ops, }, { .compatible = "fsl,mpc5200-psc-uart", .data = &mpc52xx_psc_ops, }, /* binding used by old lite5200 device trees: */ { .compatible = "mpc5200-psc-uart", .data = &mpc52xx_psc_ops, }, /* binding used by efika: */ { .compatible = "mpc5200-serial", .data = &mpc52xx_psc_ops, }, #endif #ifdef CONFIG_PPC_MPC512x { .compatible = "fsl,mpc5121-psc-uart", .data = &mpc512x_psc_ops, }, #endif {}, }; static int __devinit mpc52xx_uart_of_probe(struct platform_device *op) { int idx = -1; unsigned int uartclk; struct uart_port *port = NULL; struct resource res; int ret; /* Check validity & presence */ for (idx = 0; idx < MPC52xx_PSC_MAXNUM; idx++) if (mpc52xx_uart_nodes[idx] == op->dev.of_node) break; if (idx >= MPC52xx_PSC_MAXNUM) return -EINVAL; pr_debug("Found %s assigned to ttyPSC%x\n", mpc52xx_uart_nodes[idx]->full_name, idx); /* set the uart clock to the input clock of the psc, the different * prescalers are taken into account in the set_baudrate() methods * of the respective chip */ uartclk = mpc5xxx_get_bus_frequency(op->dev.of_node); if (uartclk == 0) { dev_dbg(&op->dev, "Could not find uart clock frequency!\n"); return -EINVAL; } /* Init the port structure */ port = &mpc52xx_uart_ports[idx]; spin_lock_init(&port->lock); port->uartclk = uartclk; port->fifosize = 512; port->iotype = UPIO_MEM; port->flags = UPF_BOOT_AUTOCONF | (uart_console(port) ? 0 : UPF_IOREMAP); port->line = idx; port->ops = &mpc52xx_uart_ops; port->dev = &op->dev; /* Search for IRQ and mapbase */ ret = of_address_to_resource(op->dev.of_node, 0, &res); if (ret) return ret; port->mapbase = res.start; if (!port->mapbase) { dev_dbg(&op->dev, "Could not allocate resources for PSC\n"); return -EINVAL; } psc_ops->get_irq(port, op->dev.of_node); if (port->irq == NO_IRQ) { dev_dbg(&op->dev, "Could not get irq\n"); return -EINVAL; } dev_dbg(&op->dev, "mpc52xx-psc uart at %p, irq=%x, freq=%i\n", (void *)port->mapbase, port->irq, port->uartclk); /* Add the port to the uart sub-system */ ret = uart_add_one_port(&mpc52xx_uart_driver, port); if (ret) return ret; dev_set_drvdata(&op->dev, (void *)port); return 0; } static int mpc52xx_uart_of_remove(struct platform_device *op) { struct uart_port *port = dev_get_drvdata(&op->dev); dev_set_drvdata(&op->dev, NULL); if (port) uart_remove_one_port(&mpc52xx_uart_driver, port); return 0; } #ifdef CONFIG_PM static int mpc52xx_uart_of_suspend(struct platform_device *op, pm_message_t state) { struct uart_port *port = (struct uart_port *) dev_get_drvdata(&op->dev); if (port) uart_suspend_port(&mpc52xx_uart_driver, port); return 0; } static int mpc52xx_uart_of_resume(struct platform_device *op) { struct uart_port *port = (struct uart_port *) dev_get_drvdata(&op->dev); if (port) uart_resume_port(&mpc52xx_uart_driver, port); return 0; } #endif static void mpc52xx_uart_of_assign(struct device_node *np) { int i; /* Find the first free PSC number */ for (i = 0; i < MPC52xx_PSC_MAXNUM; i++) { if (mpc52xx_uart_nodes[i] == NULL) { of_node_get(np); mpc52xx_uart_nodes[i] = np; return; } } } static void mpc52xx_uart_of_enumerate(void) { static int enum_done; struct device_node *np; const struct of_device_id *match; int i; if (enum_done) return; /* Assign index to each PSC in device tree */ for_each_matching_node(np, mpc52xx_uart_of_match) { match = of_match_node(mpc52xx_uart_of_match, np); psc_ops = match->data; mpc52xx_uart_of_assign(np); } enum_done = 1; for (i = 0; i < MPC52xx_PSC_MAXNUM; i++) { if (mpc52xx_uart_nodes[i]) pr_debug("%s assigned to ttyPSC%x\n", mpc52xx_uart_nodes[i]->full_name, i); } } MODULE_DEVICE_TABLE(of, mpc52xx_uart_of_match); static struct platform_driver mpc52xx_uart_of_driver = { .probe = mpc52xx_uart_of_probe, .remove = mpc52xx_uart_of_remove, #ifdef CONFIG_PM .suspend = mpc52xx_uart_of_suspend, .resume = mpc52xx_uart_of_resume, #endif .driver = { .name = "mpc52xx-psc-uart", .owner = THIS_MODULE, .of_match_table = mpc52xx_uart_of_match, }, }; /* ======================================================================== */ /* Module */ /* ======================================================================== */ static int __init mpc52xx_uart_init(void) { int ret; printk(KERN_INFO "Serial: MPC52xx PSC UART driver\n"); ret = uart_register_driver(&mpc52xx_uart_driver); if (ret) { printk(KERN_ERR "%s: uart_register_driver failed (%i)\n", __FILE__, ret); return ret; } mpc52xx_uart_of_enumerate(); /* * Map the PSC FIFO Controller and init if on MPC512x. */ if (psc_ops && psc_ops->fifoc_init) { ret = psc_ops->fifoc_init(); if (ret) return ret; } ret = platform_driver_register(&mpc52xx_uart_of_driver); if (ret) { printk(KERN_ERR "%s: platform_driver_register failed (%i)\n", __FILE__, ret); uart_unregister_driver(&mpc52xx_uart_driver); return ret; } return 0; } static void __exit mpc52xx_uart_exit(void) { if (psc_ops->fifoc_uninit) psc_ops->fifoc_uninit(); platform_driver_unregister(&mpc52xx_uart_of_driver); uart_unregister_driver(&mpc52xx_uart_driver); } module_init(mpc52xx_uart_init); module_exit(mpc52xx_uart_exit); MODULE_AUTHOR("Sylvain Munaut <tnt@246tNt.com>"); MODULE_DESCRIPTION("Freescale MPC52xx PSC UART"); MODULE_LICENSE("GPL");