| /* |
| * Synopsys DesignWare 8250 driver. |
| * |
| * Copyright 2011 Picochip, Jamie Iles. |
| * Copyright 2013 Intel Corporation |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * The Synopsys DesignWare 8250 has an extra feature whereby it detects if the |
| * LCR is written whilst busy. If it is, then a busy detect interrupt is |
| * raised, the LCR needs to be rewritten and the uart status register read. |
| */ |
| #include <linux/device.h> |
| #include <linux/init.h> |
| #include <linux/io.h> |
| #include <linux/module.h> |
| #include <linux/serial_8250.h> |
| #include <linux/serial_core.h> |
| #include <linux/serial_reg.h> |
| #include <linux/of.h> |
| #include <linux/of_irq.h> |
| #include <linux/of_platform.h> |
| #include <linux/platform_device.h> |
| #include <linux/slab.h> |
| #include <linux/acpi.h> |
| #include <linux/clk.h> |
| #include <linux/pm_runtime.h> |
| |
| #include "8250.h" |
| |
| /* Offsets for the DesignWare specific registers */ |
| #define DW_UART_USR 0x1f /* UART Status Register */ |
| #define DW_UART_CPR 0xf4 /* Component Parameter Register */ |
| #define DW_UART_UCV 0xf8 /* UART Component Version */ |
| |
| /* Component Parameter Register bits */ |
| #define DW_UART_CPR_ABP_DATA_WIDTH (3 << 0) |
| #define DW_UART_CPR_AFCE_MODE (1 << 4) |
| #define DW_UART_CPR_THRE_MODE (1 << 5) |
| #define DW_UART_CPR_SIR_MODE (1 << 6) |
| #define DW_UART_CPR_SIR_LP_MODE (1 << 7) |
| #define DW_UART_CPR_ADDITIONAL_FEATURES (1 << 8) |
| #define DW_UART_CPR_FIFO_ACCESS (1 << 9) |
| #define DW_UART_CPR_FIFO_STAT (1 << 10) |
| #define DW_UART_CPR_SHADOW (1 << 11) |
| #define DW_UART_CPR_ENCODED_PARMS (1 << 12) |
| #define DW_UART_CPR_DMA_EXTRA (1 << 13) |
| #define DW_UART_CPR_FIFO_MODE (0xff << 16) |
| /* Helper for fifo size calculation */ |
| #define DW_UART_CPR_FIFO_SIZE(a) (((a >> 16) & 0xff) * 16) |
| |
| |
| struct dw8250_data { |
| int last_lcr; |
| int line; |
| struct clk *clk; |
| }; |
| |
| static void dw8250_serial_out(struct uart_port *p, int offset, int value) |
| { |
| struct dw8250_data *d = p->private_data; |
| |
| if (offset == UART_LCR) |
| d->last_lcr = value; |
| |
| offset <<= p->regshift; |
| writeb(value, p->membase + offset); |
| } |
| |
| static unsigned int dw8250_serial_in(struct uart_port *p, int offset) |
| { |
| offset <<= p->regshift; |
| |
| return readb(p->membase + offset); |
| } |
| |
| static void dw8250_serial_out32(struct uart_port *p, int offset, int value) |
| { |
| struct dw8250_data *d = p->private_data; |
| |
| if (offset == UART_LCR) |
| d->last_lcr = value; |
| |
| offset <<= p->regshift; |
| writel(value, p->membase + offset); |
| } |
| |
| static unsigned int dw8250_serial_in32(struct uart_port *p, int offset) |
| { |
| offset <<= p->regshift; |
| |
| return readl(p->membase + offset); |
| } |
| |
| static int dw8250_handle_irq(struct uart_port *p) |
| { |
| struct dw8250_data *d = p->private_data; |
| unsigned int iir = p->serial_in(p, UART_IIR); |
| |
| if (serial8250_handle_irq(p, iir)) { |
| return 1; |
| } else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) { |
| /* Clear the USR and write the LCR again. */ |
| (void)p->serial_in(p, DW_UART_USR); |
| p->serial_out(p, UART_LCR, d->last_lcr); |
| |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| static void |
| dw8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old) |
| { |
| if (!state) |
| pm_runtime_get_sync(port->dev); |
| |
| serial8250_do_pm(port, state, old); |
| |
| if (state) |
| pm_runtime_put_sync_suspend(port->dev); |
| } |
| |
| static int dw8250_probe_of(struct uart_port *p) |
| { |
| struct device_node *np = p->dev->of_node; |
| u32 val; |
| |
| if (!of_property_read_u32(np, "reg-io-width", &val)) { |
| switch (val) { |
| case 1: |
| break; |
| case 4: |
| p->iotype = UPIO_MEM32; |
| p->serial_in = dw8250_serial_in32; |
| p->serial_out = dw8250_serial_out32; |
| break; |
| default: |
| dev_err(p->dev, "unsupported reg-io-width (%u)\n", val); |
| return -EINVAL; |
| } |
| } |
| |
| if (!of_property_read_u32(np, "reg-shift", &val)) |
| p->regshift = val; |
| |
| /* clock got configured through clk api, all done */ |
| if (p->uartclk) |
| return 0; |
| |
| /* try to find out clock frequency from DT as fallback */ |
| if (of_property_read_u32(np, "clock-frequency", &val)) { |
| dev_err(p->dev, "clk or clock-frequency not defined\n"); |
| return -EINVAL; |
| } |
| p->uartclk = val; |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_ACPI |
| static int dw8250_probe_acpi(struct uart_8250_port *up) |
| { |
| const struct acpi_device_id *id; |
| struct uart_port *p = &up->port; |
| |
| id = acpi_match_device(p->dev->driver->acpi_match_table, p->dev); |
| if (!id) |
| return -ENODEV; |
| |
| p->iotype = UPIO_MEM32; |
| p->serial_in = dw8250_serial_in32; |
| p->serial_out = dw8250_serial_out32; |
| p->regshift = 2; |
| |
| if (!p->uartclk) |
| p->uartclk = (unsigned int)id->driver_data; |
| |
| up->dma = devm_kzalloc(p->dev, sizeof(*up->dma), GFP_KERNEL); |
| if (!up->dma) |
| return -ENOMEM; |
| |
| up->dma->rxconf.src_maxburst = p->fifosize / 4; |
| up->dma->txconf.dst_maxburst = p->fifosize / 4; |
| |
| return 0; |
| } |
| #else |
| static inline int dw8250_probe_acpi(struct uart_8250_port *up) |
| { |
| return -ENODEV; |
| } |
| #endif /* CONFIG_ACPI */ |
| |
| static void dw8250_setup_port(struct uart_8250_port *up) |
| { |
| struct uart_port *p = &up->port; |
| u32 reg = readl(p->membase + DW_UART_UCV); |
| |
| /* |
| * If the Component Version Register returns zero, we know that |
| * ADDITIONAL_FEATURES are not enabled. No need to go any further. |
| */ |
| if (!reg) |
| return; |
| |
| dev_dbg_ratelimited(p->dev, "Designware UART version %c.%c%c\n", |
| (reg >> 24) & 0xff, (reg >> 16) & 0xff, (reg >> 8) & 0xff); |
| |
| reg = readl(p->membase + DW_UART_CPR); |
| if (!reg) |
| return; |
| |
| /* Select the type based on fifo */ |
| if (reg & DW_UART_CPR_FIFO_MODE) { |
| p->type = PORT_16550A; |
| p->flags |= UPF_FIXED_TYPE; |
| p->fifosize = DW_UART_CPR_FIFO_SIZE(reg); |
| up->tx_loadsz = p->fifosize; |
| up->capabilities = UART_CAP_FIFO; |
| } |
| |
| if (reg & DW_UART_CPR_AFCE_MODE) |
| up->capabilities |= UART_CAP_AFE; |
| } |
| |
| static int dw8250_probe(struct platform_device *pdev) |
| { |
| struct uart_8250_port uart = {}; |
| struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); |
| struct dw8250_data *data; |
| int err; |
| |
| if (!regs || !irq) { |
| dev_err(&pdev->dev, "no registers/irq defined\n"); |
| return -EINVAL; |
| } |
| |
| spin_lock_init(&uart.port.lock); |
| uart.port.mapbase = regs->start; |
| uart.port.irq = irq->start; |
| uart.port.handle_irq = dw8250_handle_irq; |
| uart.port.pm = dw8250_do_pm; |
| uart.port.type = PORT_8250; |
| uart.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT; |
| uart.port.dev = &pdev->dev; |
| |
| uart.port.membase = devm_ioremap(&pdev->dev, regs->start, |
| resource_size(regs)); |
| if (!uart.port.membase) |
| return -ENOMEM; |
| |
| data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); |
| if (!data) |
| return -ENOMEM; |
| |
| data->clk = devm_clk_get(&pdev->dev, NULL); |
| if (!IS_ERR(data->clk)) { |
| clk_prepare_enable(data->clk); |
| uart.port.uartclk = clk_get_rate(data->clk); |
| } |
| |
| uart.port.iotype = UPIO_MEM; |
| uart.port.serial_in = dw8250_serial_in; |
| uart.port.serial_out = dw8250_serial_out; |
| uart.port.private_data = data; |
| |
| dw8250_setup_port(&uart); |
| |
| if (pdev->dev.of_node) { |
| err = dw8250_probe_of(&uart.port); |
| if (err) |
| return err; |
| } else if (ACPI_HANDLE(&pdev->dev)) { |
| err = dw8250_probe_acpi(&uart); |
| if (err) |
| return err; |
| } else { |
| return -ENODEV; |
| } |
| |
| data->line = serial8250_register_8250_port(&uart); |
| if (data->line < 0) |
| return data->line; |
| |
| platform_set_drvdata(pdev, data); |
| |
| pm_runtime_set_active(&pdev->dev); |
| pm_runtime_enable(&pdev->dev); |
| |
| return 0; |
| } |
| |
| static int dw8250_remove(struct platform_device *pdev) |
| { |
| struct dw8250_data *data = platform_get_drvdata(pdev); |
| |
| pm_runtime_get_sync(&pdev->dev); |
| |
| serial8250_unregister_port(data->line); |
| |
| if (!IS_ERR(data->clk)) |
| clk_disable_unprepare(data->clk); |
| |
| pm_runtime_disable(&pdev->dev); |
| pm_runtime_put_noidle(&pdev->dev); |
| |
| return 0; |
| } |
| |
| #ifdef CONFIG_PM |
| static int dw8250_suspend(struct device *dev) |
| { |
| struct dw8250_data *data = dev_get_drvdata(dev); |
| |
| serial8250_suspend_port(data->line); |
| |
| return 0; |
| } |
| |
| static int dw8250_resume(struct device *dev) |
| { |
| struct dw8250_data *data = dev_get_drvdata(dev); |
| |
| serial8250_resume_port(data->line); |
| |
| return 0; |
| } |
| #endif /* CONFIG_PM */ |
| |
| #ifdef CONFIG_PM_RUNTIME |
| static int dw8250_runtime_suspend(struct device *dev) |
| { |
| struct dw8250_data *data = dev_get_drvdata(dev); |
| |
| clk_disable_unprepare(data->clk); |
| |
| return 0; |
| } |
| |
| static int dw8250_runtime_resume(struct device *dev) |
| { |
| struct dw8250_data *data = dev_get_drvdata(dev); |
| |
| clk_prepare_enable(data->clk); |
| |
| return 0; |
| } |
| #endif |
| |
| static const struct dev_pm_ops dw8250_pm_ops = { |
| SET_SYSTEM_SLEEP_PM_OPS(dw8250_suspend, dw8250_resume) |
| SET_RUNTIME_PM_OPS(dw8250_runtime_suspend, dw8250_runtime_resume, NULL) |
| }; |
| |
| static const struct of_device_id dw8250_of_match[] = { |
| { .compatible = "snps,dw-apb-uart" }, |
| { /* Sentinel */ } |
| }; |
| MODULE_DEVICE_TABLE(of, dw8250_of_match); |
| |
| static const struct acpi_device_id dw8250_acpi_match[] = { |
| { "INT33C4", 0 }, |
| { "INT33C5", 0 }, |
| { }, |
| }; |
| MODULE_DEVICE_TABLE(acpi, dw8250_acpi_match); |
| |
| static struct platform_driver dw8250_platform_driver = { |
| .driver = { |
| .name = "dw-apb-uart", |
| .owner = THIS_MODULE, |
| .pm = &dw8250_pm_ops, |
| .of_match_table = dw8250_of_match, |
| .acpi_match_table = ACPI_PTR(dw8250_acpi_match), |
| }, |
| .probe = dw8250_probe, |
| .remove = dw8250_remove, |
| }; |
| |
| module_platform_driver(dw8250_platform_driver); |
| |
| MODULE_AUTHOR("Jamie Iles"); |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("Synopsys DesignWare 8250 serial port driver"); |