| /* |
| * 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; |
| 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"); |