Initial file dump from open source releaseHEADmaster

1 files changed, 437 insertions, 0 deletions

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
new file mode 100644
index 00000000..345b5ddc
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -0,0 +1,437 @@
+/*
+ * 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_mcr;
+	int		line;
+	struct clk	*clk;
+};
+
+static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = p->private_data;
+
+	/* If reading MSR, report CTS asserted when auto-CTS/RTS enabled */
+	if (offset == UART_MSR && d->last_mcr & UART_MCR_AFE) {
+		value |= UART_MSR_CTS;
+		value &= ~UART_MSR_DCTS;
+	}
+
+	return value;
+}
+
+static void dw8250_force_idle(struct uart_port *p)
+{
+	serial8250_clear_and_reinit_fifos(container_of
+					  (p, struct uart_8250_port, port));
+	(void)p->serial_in(p, UART_RX);
+}
+
+static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = p->private_data;
+
+	if (offset == UART_MCR)
+		d->last_mcr = value;
+
+	writeb(value, p->membase + (offset << p->regshift));
+
+	/* Make sure LCR write wasn't ignored */
+	if (offset == UART_LCR) {
+		int tries = 1000;
+		while (tries--) {
+			unsigned int lcr = p->serial_in(p, UART_LCR);
+			if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
+				return;
+			dw8250_force_idle(p);
+			writeb(value, p->membase + (UART_LCR << p->regshift));
+		}
+		dev_err(p->dev, "Couldn't set LCR to %d\n", value);
+	}
+}
+
+static unsigned int dw8250_serial_in(struct uart_port *p, int offset)
+{
+	unsigned int value = readb(p->membase + (offset << p->regshift));
+
+	return dw8250_modify_msr(p, offset, value);
+}
+
+static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = p->private_data;
+
+	if (offset == UART_MCR)
+		d->last_mcr = value;
+
+	writel(value, p->membase + (offset << p->regshift));
+
+	/* Make sure LCR write wasn't ignored */
+	if (offset == UART_LCR) {
+		int tries = 1000;
+		while (tries--) {
+			unsigned int lcr = p->serial_in(p, UART_LCR);
+			if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
+				return;
+			dw8250_force_idle(p);
+			writel(value, p->membase + (UART_LCR << p->regshift));
+		}
+		dev_err(p->dev, "Couldn't set LCR to %d\n", value);
+	}
+}
+
+static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
+{
+	unsigned int value = readl(p->membase + (offset << p->regshift));
+
+	return dw8250_modify_msr(p, offset, value);
+}
+
+static int dw8250_handle_irq(struct uart_port *p)
+{
+	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 */
+		(void)p->serial_in(p, DW_UART_USR);
+
+		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);
+
+	if (!IS_ERR(data->clk))
+		clk_disable_unprepare(data->clk);
+
+	return 0;
+}
+
+static int dw8250_runtime_resume(struct device *dev)
+{
+	struct dw8250_data *data = dev_get_drvdata(dev);
+
+	if (!IS_ERR(data->clk))
+		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 },
+	{ "INT3434", 0 },
+	{ "INT3435", 0 },
+	{ "80860F0A", 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");