/* * 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> /* 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; unsigned int open; /* Prevent concurrent writes to PSIF THR. */ spinlock_t lock; }; 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 = 1; out: return retval; } static void psif_close(struct serio *io) { struct psif *psif = io->port_data; psif->open = 0; 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); platform_set_drvdata(pdev, NULL); return 0; } #ifdef CONFIG_PM static int psif_suspend(struct platform_device *pdev, pm_message_t state) { 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 platform_device *pdev) { 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; } #else #define psif_suspend NULL #define psif_resume NULL #endif static struct platform_driver psif_driver = { .remove = __exit_p(psif_remove), .driver = { .name = "atmel_psif", .owner = THIS_MODULE, }, .suspend = psif_suspend, .resume = psif_resume, }; static int __init psif_init(void) { return platform_driver_probe(&psif_driver, psif_probe); } static void __exit psif_exit(void) { platform_driver_unregister(&psif_driver); } module_init(psif_init); module_exit(psif_exit); MODULE_AUTHOR("Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>"); MODULE_DESCRIPTION("Atmel AVR32 PSIF PS/2 driver"); MODULE_LICENSE("GPL");