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![Krzysztof Kozlowski](/assets/img/avatar_default.png)
platform_get_irq() returns -ERRNO on error. In such case comparison
to 0 would pass the check.
Fixes: e443631d20
("Input: serio - add support for Alwinner A10/A20 PS/2 controller")
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20200828145744.3636-4-krzk@kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
338 lines
8.6 KiB
C
338 lines
8.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Driver for Allwinner A10 PS2 host controller
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*
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* Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
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* Aaron.maoye <leafy.myeh@newbietech.com>
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*/
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#include <linux/module.h>
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#include <linux/serio.h>
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#include <linux/interrupt.h>
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#include <linux/errno.h>
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#include <linux/slab.h>
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#include <linux/io.h>
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#include <linux/clk.h>
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#include <linux/mod_devicetable.h>
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#include <linux/platform_device.h>
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#define DRIVER_NAME "sun4i-ps2"
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/* register offset definitions */
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#define PS2_REG_GCTL 0x00 /* PS2 Module Global Control Reg */
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#define PS2_REG_DATA 0x04 /* PS2 Module Data Reg */
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#define PS2_REG_LCTL 0x08 /* PS2 Module Line Control Reg */
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#define PS2_REG_LSTS 0x0C /* PS2 Module Line Status Reg */
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#define PS2_REG_FCTL 0x10 /* PS2 Module FIFO Control Reg */
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#define PS2_REG_FSTS 0x14 /* PS2 Module FIFO Status Reg */
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#define PS2_REG_CLKDR 0x18 /* PS2 Module Clock Divider Reg*/
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/* PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
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#define PS2_GCTL_INTFLAG BIT(4)
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#define PS2_GCTL_INTEN BIT(3)
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#define PS2_GCTL_RESET BIT(2)
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#define PS2_GCTL_MASTER BIT(1)
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#define PS2_GCTL_BUSEN BIT(0)
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/* PS2 LINE CONTROL REGISTER */
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#define PS2_LCTL_NOACK BIT(18)
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#define PS2_LCTL_TXDTOEN BIT(8)
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#define PS2_LCTL_STOPERREN BIT(3)
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#define PS2_LCTL_ACKERREN BIT(2)
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#define PS2_LCTL_PARERREN BIT(1)
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#define PS2_LCTL_RXDTOEN BIT(0)
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/* PS2 LINE STATUS REGISTER */
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#define PS2_LSTS_TXTDO BIT(8)
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#define PS2_LSTS_STOPERR BIT(3)
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#define PS2_LSTS_ACKERR BIT(2)
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#define PS2_LSTS_PARERR BIT(1)
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#define PS2_LSTS_RXTDO BIT(0)
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#define PS2_LINE_ERROR_BIT \
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(PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \
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PS2_LSTS_PARERR | PS2_LSTS_RXTDO)
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/* PS2 FIFO CONTROL REGISTER */
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#define PS2_FCTL_TXRST BIT(17)
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#define PS2_FCTL_RXRST BIT(16)
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#define PS2_FCTL_TXUFIEN BIT(10)
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#define PS2_FCTL_TXOFIEN BIT(9)
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#define PS2_FCTL_TXRDYIEN BIT(8)
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#define PS2_FCTL_RXUFIEN BIT(2)
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#define PS2_FCTL_RXOFIEN BIT(1)
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#define PS2_FCTL_RXRDYIEN BIT(0)
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/* PS2 FIFO STATUS REGISTER */
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#define PS2_FSTS_TXUF BIT(10)
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#define PS2_FSTS_TXOF BIT(9)
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#define PS2_FSTS_TXRDY BIT(8)
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#define PS2_FSTS_RXUF BIT(2)
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#define PS2_FSTS_RXOF BIT(1)
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#define PS2_FSTS_RXRDY BIT(0)
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#define PS2_FIFO_ERROR_BIT \
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(PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF)
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#define PS2_SAMPLE_CLK 1000000
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#define PS2_SCLK 125000
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struct sun4i_ps2data {
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struct serio *serio;
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struct device *dev;
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/* IO mapping base */
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void __iomem *reg_base;
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/* clock management */
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struct clk *clk;
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/* irq */
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spinlock_t lock;
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int irq;
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};
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static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
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{
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struct sun4i_ps2data *drvdata = dev_id;
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u32 intr_status;
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u32 fifo_status;
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unsigned char byte;
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unsigned int rxflags = 0;
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u32 rval;
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spin_lock(&drvdata->lock);
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/* Get the PS/2 interrupts and clear them */
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intr_status = readl(drvdata->reg_base + PS2_REG_LSTS);
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fifo_status = readl(drvdata->reg_base + PS2_REG_FSTS);
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/* Check line status register */
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if (intr_status & PS2_LINE_ERROR_BIT) {
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rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
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rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
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rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;
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rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR |
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PS2_LSTS_PARERR | PS2_LSTS_RXTDO;
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writel(rval, drvdata->reg_base + PS2_REG_LSTS);
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}
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/* Check FIFO status register */
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if (fifo_status & PS2_FIFO_ERROR_BIT) {
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rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY |
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PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY;
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writel(rval, drvdata->reg_base + PS2_REG_FSTS);
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}
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rval = (fifo_status >> 16) & 0x3;
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while (rval--) {
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byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
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serio_interrupt(drvdata->serio, byte, rxflags);
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}
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writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
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writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);
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spin_unlock(&drvdata->lock);
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return IRQ_HANDLED;
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}
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static int sun4i_ps2_open(struct serio *serio)
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{
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struct sun4i_ps2data *drvdata = serio->port_data;
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u32 src_clk = 0;
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u32 clk_scdf;
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u32 clk_pcdf;
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u32 rval;
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unsigned long flags;
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/* Set line control and enable interrupt */
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rval = PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN
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| PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN;
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writel(rval, drvdata->reg_base + PS2_REG_LCTL);
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/* Reset FIFO */
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rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN
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| PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN
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| PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN;
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writel(rval, drvdata->reg_base + PS2_REG_FCTL);
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src_clk = clk_get_rate(drvdata->clk);
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/* Set clock divider register */
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clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
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clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
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rval = (clk_scdf << 8) | clk_pcdf;
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writel(rval, drvdata->reg_base + PS2_REG_CLKDR);
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/* Set global control register */
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rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER
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| PS2_GCTL_BUSEN;
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spin_lock_irqsave(&drvdata->lock, flags);
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writel(rval, drvdata->reg_base + PS2_REG_GCTL);
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spin_unlock_irqrestore(&drvdata->lock, flags);
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return 0;
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}
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static void sun4i_ps2_close(struct serio *serio)
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{
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struct sun4i_ps2data *drvdata = serio->port_data;
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u32 rval;
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/* Shut off the interrupt */
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rval = readl(drvdata->reg_base + PS2_REG_GCTL);
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writel(rval & ~(PS2_GCTL_INTEN), drvdata->reg_base + PS2_REG_GCTL);
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synchronize_irq(drvdata->irq);
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}
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static int sun4i_ps2_write(struct serio *serio, unsigned char val)
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{
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unsigned long expire = jiffies + msecs_to_jiffies(10000);
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struct sun4i_ps2data *drvdata = serio->port_data;
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do {
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if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
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writel(val, drvdata->reg_base + PS2_REG_DATA);
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return 0;
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}
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} while (time_before(jiffies, expire));
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return SERIO_TIMEOUT;
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}
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static int sun4i_ps2_probe(struct platform_device *pdev)
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{
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struct resource *res; /* IO mem resources */
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struct sun4i_ps2data *drvdata;
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struct serio *serio;
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struct device *dev = &pdev->dev;
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int error;
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drvdata = kzalloc(sizeof(struct sun4i_ps2data), GFP_KERNEL);
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serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
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if (!drvdata || !serio) {
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error = -ENOMEM;
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goto err_free_mem;
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}
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spin_lock_init(&drvdata->lock);
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/* IO */
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res) {
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dev_err(dev, "failed to locate registers\n");
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error = -ENXIO;
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goto err_free_mem;
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}
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drvdata->reg_base = ioremap(res->start, resource_size(res));
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if (!drvdata->reg_base) {
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dev_err(dev, "failed to map registers\n");
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error = -ENOMEM;
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goto err_free_mem;
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}
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drvdata->clk = clk_get(dev, NULL);
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if (IS_ERR(drvdata->clk)) {
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error = PTR_ERR(drvdata->clk);
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dev_err(dev, "couldn't get clock %d\n", error);
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goto err_ioremap;
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}
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error = clk_prepare_enable(drvdata->clk);
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if (error) {
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dev_err(dev, "failed to enable clock %d\n", error);
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goto err_clk;
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}
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serio->id.type = SERIO_8042;
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serio->write = sun4i_ps2_write;
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serio->open = sun4i_ps2_open;
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serio->close = sun4i_ps2_close;
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serio->port_data = drvdata;
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serio->dev.parent = dev;
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strlcpy(serio->name, dev_name(dev), sizeof(serio->name));
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strlcpy(serio->phys, dev_name(dev), sizeof(serio->phys));
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/* shutoff interrupt */
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writel(0, drvdata->reg_base + PS2_REG_GCTL);
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/* Get IRQ for the device */
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drvdata->irq = platform_get_irq(pdev, 0);
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if (drvdata->irq < 0) {
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error = drvdata->irq;
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goto err_disable_clk;
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}
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drvdata->serio = serio;
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drvdata->dev = dev;
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error = request_irq(drvdata->irq, sun4i_ps2_interrupt, 0,
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DRIVER_NAME, drvdata);
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if (error) {
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dev_err(drvdata->dev, "failed to allocate interrupt %d: %d\n",
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drvdata->irq, error);
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goto err_disable_clk;
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}
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serio_register_port(serio);
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platform_set_drvdata(pdev, drvdata);
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return 0; /* success */
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err_disable_clk:
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clk_disable_unprepare(drvdata->clk);
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err_clk:
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clk_put(drvdata->clk);
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err_ioremap:
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iounmap(drvdata->reg_base);
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err_free_mem:
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kfree(serio);
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kfree(drvdata);
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return error;
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}
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static int sun4i_ps2_remove(struct platform_device *pdev)
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{
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struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);
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serio_unregister_port(drvdata->serio);
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free_irq(drvdata->irq, drvdata);
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clk_disable_unprepare(drvdata->clk);
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clk_put(drvdata->clk);
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iounmap(drvdata->reg_base);
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kfree(drvdata);
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return 0;
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}
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static const struct of_device_id sun4i_ps2_match[] = {
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{ .compatible = "allwinner,sun4i-a10-ps2", },
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{ },
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};
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MODULE_DEVICE_TABLE(of, sun4i_ps2_match);
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static struct platform_driver sun4i_ps2_driver = {
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.probe = sun4i_ps2_probe,
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.remove = sun4i_ps2_remove,
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.driver = {
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.name = DRIVER_NAME,
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.of_match_table = sun4i_ps2_match,
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},
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};
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module_platform_driver(sun4i_ps2_driver);
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MODULE_AUTHOR("Vishnu Patekar <vishnupatekar0510@gmail.com>");
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MODULE_AUTHOR("Aaron.maoye <leafy.myeh@newbietech.com>");
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MODULE_DESCRIPTION("Allwinner A10/Sun4i PS/2 driver");
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MODULE_LICENSE("GPL v2");
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