diff options
Diffstat (limited to 'drivers/input/serio/at32psif.c')
| -rw-r--r-- | drivers/input/serio/at32psif.c | 363 |
1 files changed, 363 insertions, 0 deletions
diff --git a/drivers/input/serio/at32psif.c b/drivers/input/serio/at32psif.c new file mode 100644 index 000000000..2e4ff5bac --- /dev/null +++ b/drivers/input/serio/at32psif.c @@ -0,0 +1,363 @@ +/* + * Copyright (C) 2007 Atmel Corporation + * + * Driver for the AT32AP700X PS/2 controller (PSIF). + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/init.h> +#include <linux/serio.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +/* PSIF register offsets */ +#define PSIF_CR 0x00 +#define PSIF_RHR 0x04 +#define PSIF_THR 0x08 +#define PSIF_SR 0x10 +#define PSIF_IER 0x14 +#define PSIF_IDR 0x18 +#define PSIF_IMR 0x1c +#define PSIF_PSR 0x24 + +/* Bitfields in control register. */ +#define PSIF_CR_RXDIS_OFFSET 1 +#define PSIF_CR_RXDIS_SIZE 1 +#define PSIF_CR_RXEN_OFFSET 0 +#define PSIF_CR_RXEN_SIZE 1 +#define PSIF_CR_SWRST_OFFSET 15 +#define PSIF_CR_SWRST_SIZE 1 +#define PSIF_CR_TXDIS_OFFSET 9 +#define PSIF_CR_TXDIS_SIZE 1 +#define PSIF_CR_TXEN_OFFSET 8 +#define PSIF_CR_TXEN_SIZE 1 + +/* Bitfields in interrupt disable, enable, mask and status register. */ +#define PSIF_NACK_OFFSET 8 +#define PSIF_NACK_SIZE 1 +#define PSIF_OVRUN_OFFSET 5 +#define PSIF_OVRUN_SIZE 1 +#define PSIF_PARITY_OFFSET 9 +#define PSIF_PARITY_SIZE 1 +#define PSIF_RXRDY_OFFSET 4 +#define PSIF_RXRDY_SIZE 1 +#define PSIF_TXEMPTY_OFFSET 1 +#define PSIF_TXEMPTY_SIZE 1 +#define PSIF_TXRDY_OFFSET 0 +#define PSIF_TXRDY_SIZE 1 + +/* Bitfields in prescale register. */ +#define PSIF_PSR_PRSCV_OFFSET 0 +#define PSIF_PSR_PRSCV_SIZE 12 + +/* Bitfields in receive hold register. */ +#define PSIF_RHR_RXDATA_OFFSET 0 +#define PSIF_RHR_RXDATA_SIZE 8 + +/* Bitfields in transmit hold register. */ +#define PSIF_THR_TXDATA_OFFSET 0 +#define PSIF_THR_TXDATA_SIZE 8 + +/* Bit manipulation macros */ +#define PSIF_BIT(name) \ + (1 << PSIF_##name##_OFFSET) + +#define PSIF_BF(name, value) \ + (((value) & ((1 << PSIF_##name##_SIZE) - 1)) \ + << PSIF_##name##_OFFSET) + +#define PSIF_BFEXT(name, value) \ + (((value) >> PSIF_##name##_OFFSET) \ + & ((1 << PSIF_##name##_SIZE) - 1)) + +#define PSIF_BFINS(name, value, old) \ + (((old) & ~(((1 << PSIF_##name##_SIZE) - 1) \ + << PSIF_##name##_OFFSET)) \ + | PSIF_BF(name, value)) + +/* Register access macros */ +#define psif_readl(port, reg) \ + __raw_readl((port)->regs + PSIF_##reg) + +#define psif_writel(port, reg, value) \ + __raw_writel((value), (port)->regs + PSIF_##reg) + +struct psif { + struct platform_device *pdev; + struct clk *pclk; + struct serio *io; + void __iomem *regs; + unsigned int irq; + /* Prevent concurrent writes to PSIF THR. */ + spinlock_t lock; + bool open; +}; + +static irqreturn_t psif_interrupt(int irq, void *_ptr) +{ + struct psif *psif = _ptr; + int retval = IRQ_NONE; + unsigned int io_flags = 0; + unsigned long status; + + status = psif_readl(psif, SR); + + if (status & PSIF_BIT(RXRDY)) { + unsigned char val = (unsigned char) psif_readl(psif, RHR); + + if (status & PSIF_BIT(PARITY)) + io_flags |= SERIO_PARITY; + if (status & PSIF_BIT(OVRUN)) + dev_err(&psif->pdev->dev, "overrun read error\n"); + + serio_interrupt(psif->io, val, io_flags); + + retval = IRQ_HANDLED; + } + + return retval; +} + +static int psif_write(struct serio *io, unsigned char val) +{ + struct psif *psif = io->port_data; + unsigned long flags; + int timeout = 10; + int retval = 0; + + spin_lock_irqsave(&psif->lock, flags); + + while (!(psif_readl(psif, SR) & PSIF_BIT(TXEMPTY)) && timeout--) + udelay(50); + + if (timeout >= 0) { + psif_writel(psif, THR, val); + } else { + dev_dbg(&psif->pdev->dev, "timeout writing to THR\n"); + retval = -EBUSY; + } + + spin_unlock_irqrestore(&psif->lock, flags); + + return retval; +} + +static int psif_open(struct serio *io) +{ + struct psif *psif = io->port_data; + int retval; + + retval = clk_enable(psif->pclk); + if (retval) + goto out; + + psif_writel(psif, CR, PSIF_BIT(CR_TXEN) | PSIF_BIT(CR_RXEN)); + psif_writel(psif, IER, PSIF_BIT(RXRDY)); + + psif->open = true; +out: + return retval; +} + +static void psif_close(struct serio *io) +{ + struct psif *psif = io->port_data; + + psif->open = false; + + psif_writel(psif, IDR, ~0UL); + psif_writel(psif, CR, PSIF_BIT(CR_TXDIS) | PSIF_BIT(CR_RXDIS)); + + clk_disable(psif->pclk); +} + +static void psif_set_prescaler(struct psif *psif) +{ + unsigned long prscv; + unsigned long rate = clk_get_rate(psif->pclk); + + /* PRSCV = Pulse length (100 us) * PSIF module frequency. */ + prscv = 100 * (rate / 1000000UL); + + if (prscv > ((1<<PSIF_PSR_PRSCV_SIZE) - 1)) { + prscv = (1<<PSIF_PSR_PRSCV_SIZE) - 1; + dev_dbg(&psif->pdev->dev, "pclk too fast, " + "prescaler set to max\n"); + } + + clk_enable(psif->pclk); + psif_writel(psif, PSR, prscv); + clk_disable(psif->pclk); +} + +static int __init psif_probe(struct platform_device *pdev) +{ + struct resource *regs; + struct psif *psif; + struct serio *io; + struct clk *pclk; + int irq; + int ret; + + psif = kzalloc(sizeof(struct psif), GFP_KERNEL); + if (!psif) { + dev_dbg(&pdev->dev, "out of memory\n"); + ret = -ENOMEM; + goto out; + } + psif->pdev = pdev; + + io = kzalloc(sizeof(struct serio), GFP_KERNEL); + if (!io) { + dev_dbg(&pdev->dev, "out of memory\n"); + ret = -ENOMEM; + goto out_free_psif; + } + psif->io = io; + + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!regs) { + dev_dbg(&pdev->dev, "no mmio resources defined\n"); + ret = -ENOMEM; + goto out_free_io; + } + + psif->regs = ioremap(regs->start, resource_size(regs)); + if (!psif->regs) { + ret = -ENOMEM; + dev_dbg(&pdev->dev, "could not map I/O memory\n"); + goto out_free_io; + } + + pclk = clk_get(&pdev->dev, "pclk"); + if (IS_ERR(pclk)) { + dev_dbg(&pdev->dev, "could not get peripheral clock\n"); + ret = PTR_ERR(pclk); + goto out_iounmap; + } + psif->pclk = pclk; + + /* Reset the PSIF to enter at a known state. */ + ret = clk_enable(pclk); + if (ret) { + dev_dbg(&pdev->dev, "could not enable pclk\n"); + goto out_put_clk; + } + psif_writel(psif, CR, PSIF_BIT(CR_SWRST)); + clk_disable(pclk); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_dbg(&pdev->dev, "could not get irq\n"); + ret = -ENXIO; + goto out_put_clk; + } + ret = request_irq(irq, psif_interrupt, IRQF_SHARED, "at32psif", psif); + if (ret) { + dev_dbg(&pdev->dev, "could not request irq %d\n", irq); + goto out_put_clk; + } + psif->irq = irq; + + io->id.type = SERIO_8042; + io->write = psif_write; + io->open = psif_open; + io->close = psif_close; + snprintf(io->name, sizeof(io->name), "AVR32 PS/2 port%d", pdev->id); + snprintf(io->phys, sizeof(io->phys), "at32psif/serio%d", pdev->id); + io->port_data = psif; + io->dev.parent = &pdev->dev; + + psif_set_prescaler(psif); + + spin_lock_init(&psif->lock); + serio_register_port(psif->io); + platform_set_drvdata(pdev, psif); + + dev_info(&pdev->dev, "Atmel AVR32 PSIF PS/2 driver on 0x%08x irq %d\n", + (int)psif->regs, psif->irq); + + return 0; + +out_put_clk: + clk_put(psif->pclk); +out_iounmap: + iounmap(psif->regs); +out_free_io: + kfree(io); +out_free_psif: + kfree(psif); +out: + return ret; +} + +static int __exit psif_remove(struct platform_device *pdev) +{ + struct psif *psif = platform_get_drvdata(pdev); + + psif_writel(psif, IDR, ~0UL); + psif_writel(psif, CR, PSIF_BIT(CR_TXDIS) | PSIF_BIT(CR_RXDIS)); + + serio_unregister_port(psif->io); + iounmap(psif->regs); + free_irq(psif->irq, psif); + clk_put(psif->pclk); + kfree(psif); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int psif_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct psif *psif = platform_get_drvdata(pdev); + + if (psif->open) { + psif_writel(psif, CR, PSIF_BIT(CR_RXDIS) | PSIF_BIT(CR_TXDIS)); + clk_disable(psif->pclk); + } + + return 0; +} + +static int psif_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct psif *psif = platform_get_drvdata(pdev); + + if (psif->open) { + clk_enable(psif->pclk); + psif_set_prescaler(psif); + psif_writel(psif, CR, PSIF_BIT(CR_RXEN) | PSIF_BIT(CR_TXEN)); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(psif_pm_ops, psif_suspend, psif_resume); + +static struct platform_driver psif_driver = { + .remove = __exit_p(psif_remove), + .driver = { + .name = "atmel_psif", + .pm = &psif_pm_ops, + }, +}; + +module_platform_driver_probe(psif_driver, psif_probe); + +MODULE_AUTHOR("Hans-Christian Egtvedt <egtvedt@samfundet.no>"); +MODULE_DESCRIPTION("Atmel AVR32 PSIF PS/2 driver"); +MODULE_LICENSE("GPL"); |