Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752393AbaLNUiT (ORCPT ); Sun, 14 Dec 2014 15:38:19 -0500 Received: from mail-ie0-f177.google.com ([209.85.223.177]:61962 "EHLO mail-ie0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751689AbaLNUiE (ORCPT ); Sun, 14 Dec 2014 15:38:04 -0500 Date: Sun, 14 Dec 2014 12:37:59 -0800 From: Dmitry Torokhov To: VishnuPatekar Cc: linux-input@vger.kernel.org, maxime.ripard@free-electrons.com, hdegoede@redhat.com, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, linux@arm.linux.org.uk, grant.likely@linaro.org, benh@kernel.crashing.org, msalter@redhat.com, ralf@linux-mips.org, jdelvare@suse.de Subject: Re: [PATCHv3 2/5] ARM:sunxi:drivers:input Add support for A10/A20 PS2 Message-ID: <20141214203759.GA36053@dtor-ws> References: <1418408748-9797-1-git-send-email-vishnupatekar0510@gmail.com> <1418408748-9797-3-git-send-email-vishnupatekar0510@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1418408748-9797-3-git-send-email-vishnupatekar0510@gmail.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vishnu, On Fri, Dec 12, 2014 at 11:55:45PM +0530, VishnuPatekar wrote: > > Signed-off-by: VishnuPatekar > --- > drivers/input/serio/Kconfig | 11 ++ > drivers/input/serio/Makefile | 1 + > drivers/input/serio/sun4i-ps2.c | 362 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 374 insertions(+) > create mode 100644 drivers/input/serio/sun4i-ps2.c > > diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig > index bc2d474..964afc5 100644 > --- a/drivers/input/serio/Kconfig > +++ b/drivers/input/serio/Kconfig > @@ -281,4 +281,15 @@ config HYPERV_KEYBOARD > To compile this driver as a module, choose M here: the module will > be called hyperv_keyboard. > > +config SERIO_SUN4I_PS2 > + tristate "Allwinner A10 PS/2 controller support" > + default n > + depends on ARCH_SUNXI || COMPILE_TEST > + help > + This selects support for the PS/2 Host Controller on > + Allwinner A10. > + > + To compile this driver as a module, choose M here: the > + module will be called sun4i-ps2. > + > endif > diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile > index 815d874..c600089 100644 > --- a/drivers/input/serio/Makefile > +++ b/drivers/input/serio/Makefile > @@ -29,3 +29,4 @@ obj-$(CONFIG_SERIO_ARC_PS2) += arc_ps2.o > obj-$(CONFIG_SERIO_APBPS2) += apbps2.o > obj-$(CONFIG_SERIO_OLPC_APSP) += olpc_apsp.o > obj-$(CONFIG_HYPERV_KEYBOARD) += hyperv-keyboard.o > +obj-$(CONFIG_SERIO_SUN4I_PS2) += sun4i-ps2.o > diff --git a/drivers/input/serio/sun4i-ps2.c b/drivers/input/serio/sun4i-ps2.c > new file mode 100644 > index 0000000..e6d22ae > --- /dev/null > +++ b/drivers/input/serio/sun4i-ps2.c > @@ -0,0 +1,362 @@ > +/* > + * Driver for Allwinner A10 PS2 host controller > + * > + * Author: Vishnu Patekar > + * Aaron.maoye > + * > + * > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define DRIVER_NAME "sun4i-ps2" > + > +/* register offset definitions */ > +#define PS2_REG_GCTL (0x00) /* PS2 Module Global Control Reg */ > +#define PS2_REG_DATA (0x04) /* PS2 Module Data Reg */ > +#define PS2_REG_LCTL (0x08) /* PS2 Module Line Control Reg */ > +#define PS2_REG_LSTS (0x0C) /* PS2 Module Line Status Reg */ > +#define PS2_REG_FCTL (0x10) /* PS2 Module FIFO Control Reg */ > +#define PS2_REG_FSTS (0x14) /* PS2 Module FIFO Status Reg */ > +#define PS2_REG_CLKDR (0x18) /* PS2 Module Clock Divider Reg*/ You do not need parenthesis around simple constants. > + > +/* PS2 GLOBAL CONTROL REGISTER PS2_GCTL */ > +#define PS2_GCTL_INTFLAG BIT(4) > +#define PS2_GCTL_INTEN BIT(3) > +#define PS2_GCTL_RESET BIT(2) > +#define PS2_GCTL_MASTER BIT(1) > +#define PS2_GCTL_BUSEN BIT(0) > + > +/* PS2 LINE CONTROL REGISTER */ > +#define PS2_LCTL_NOACK BIT(18) > +#define PS2_LCTL_TXDTOEN BIT(8) > +#define PS2_LCTL_STOPERREN BIT(3) > +#define PS2_LCTL_ACKERREN BIT(2) > +#define PS2_LCTL_PARERREN BIT(1) > +#define PS2_LCTL_RXDTOEN BIT(0) > + > +/* PS2 LINE STATUS REGISTER */ > +#define PS2_LSTS_TXTDO BIT(8) > +#define PS2_LSTS_STOPERR BIT(3) > +#define PS2_LSTS_ACKERR BIT(2) > +#define PS2_LSTS_PARERR BIT(1) > +#define PS2_LSTS_RXTDO BIT(0) > + > +#define PS2_LINE_ERROR_BIT \ > + (PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \ > + PS2_LSTS_PARERR | PS2_LSTS_RXTDO) > + > +/* PS2 FIFO CONTROL REGISTER */ > +#define PS2_FCTL_TXRST BIT(17) > +#define PS2_FCTL_RXRST BIT(16) > +#define PS2_FCTL_TXUFIEN BIT(10) > +#define PS2_FCTL_TXOFIEN BIT(9) > +#define PS2_FCTL_TXRDYIEN BIT(8) > +#define PS2_FCTL_RXUFIEN BIT(2) > +#define PS2_FCTL_RXOFIEN BIT(1) > +#define PS2_FCTL_RXRDYIEN BIT(0) > + > +/* PS2 FIFO STATUS REGISTER */ > +#define PS2_FSTS_TXUF BIT(10) > +#define PS2_FSTS_TXOF BIT(9) > +#define PS2_FSTS_TXRDY BIT(8) > +#define PS2_FSTS_RXUF BIT(2) > +#define PS2_FSTS_RXOF BIT(1) > +#define PS2_FSTS_RXRDY BIT(0) > + > +#define PS2_FIFO_ERROR_BIT \ > + (PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF) > + > +#define PS2_SAMPLE_CLK (1000000) > +#define PS2_SCLK (125000) > + > +struct sun4i_ps2data { > + struct serio *serio; > + struct device *dev; > + > + /* IO mapping base */ > + void __iomem *reg_base; > + > + /* clock management */ > + struct clk *clk; > + > + /* irq */ > + spinlock_t lock; > + int irq; > +}; > + > +/*********************/ > +/* Interrupt handler */ > +/*********************/ > +static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id) > +{ > + struct sun4i_ps2data *drvdata = dev_id; > + u32 intr_status; > + u32 fifo_status; > + unsigned char byte; > + u32 rval; > + u32 error = 0; > + > + spin_lock(&drvdata->lock); > + > + /* Get the PS/2 interrupts and clear them */ > + intr_status = readl(drvdata->reg_base + PS2_REG_LSTS); > + fifo_status = readl(drvdata->reg_base + PS2_REG_FSTS); > + > + /*Check Line Status Register*/ > + if (intr_status & PS2_LINE_ERROR_BIT) { > + if (intr_status & PS2_LSTS_STOPERR) > + dev_info(drvdata->dev, "PS/2 Stop Bit Error!"); The stop bit error is I believe should be reported to consumers as SSERIO_FRAME, receive timeout as SERIO_TIMEOUT and parity as SERIO_PARITY. > + if (intr_status & PS2_LSTS_ACKERR) > + dev_info(drvdata->dev, "PS/2 Acknowledge Error!\n"); When is this error signalled? > + if (intr_status & PS2_LSTS_PARERR) > + dev_info(drvdata->dev, "PS/2 Parity Error!\n"); > + if (intr_status & PS2_LSTS_TXTDO) > + dev_info(drvdata->dev, "PS/2 Transmit Data Timeout!\n"); Should not you check this status in serio_write() instead of here? > + if (intr_status & PS2_LSTS_RXTDO) > + dev_info(drvdata->dev, "PS/2 Receive Data Timeout!\n"); > + > + /*reset PS/2 controller*/ > + rval = readl(drvdata->reg_base + PS2_REG_GCTL); > + writel(rval | PS2_GCTL_RESET, drvdata->reg_base + PS2_REG_GCTL); Why do we need to reset controller in case of, let's say, parity glitch? > + > + rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | > + PS2_LSTS_PARERR | PS2_LSTS_RXTDO; > + writel(rval, drvdata->reg_base + PS2_REG_LSTS); > + error = 1; > + } > + > + /*Check FIFO Status Register*/ > + if (fifo_status & PS2_FIFO_ERROR_BIT) { > + if (fifo_status & PS2_FSTS_TXUF) > + dev_info(drvdata->dev, "PS/2 Tx FIFO Underflow!\n"); > + if (fifo_status & PS2_FSTS_TXOF) > + dev_info(drvdata->dev, "PS/2 Tx FIFO Overflow!\n"); > + if (fifo_status & PS2_FSTS_RXUF) > + dev_info(drvdata->dev, "PS/2 Rx FIFO Underflow!\n"); > + if (fifo_status & PS2_FSTS_RXOF) > + dev_info(drvdata->dev, "PS/2 Rx FIFO Overflow!\n"); > + /*reset PS/2 controller*/ > + writel(readl(drvdata->reg_base + PS2_REG_GCTL) | PS2_GCTL_RESET, > + drvdata->reg_base + PS2_REG_GCTL); Again, we do we need to reset controller? Does it stop receiving data after RX overflow condition? > + > + rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY | > + PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY; > + writel(rval, drvdata->reg_base + PS2_REG_FSTS); > + error = 1; > + } > + > + rval = (fifo_status >> 16) & 0x3; > + while (!error && rval--) { > + byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff; > + serio_interrupt(drvdata->serio, byte, 0); > + } > + > + writel(intr_status, drvdata->reg_base + PS2_REG_LSTS); > + writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS); > + > + spin_unlock(&drvdata->lock); > + > + return IRQ_HANDLED; > +} > + > + > +static int sun4i_ps2_open(struct serio *pserio) > +{ > + struct sun4i_ps2data *drvdata = pserio->port_data; > + u32 src_clk = 0; > + u32 clk_scdf; > + u32 clk_pcdf; > + u32 rval; > + unsigned long flags; > + > + /*Set Line Control And Enable Interrupt*/ > + rval = PS2_LCTL_TXDTOEN | PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN > + | PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN; > + writel(rval, drvdata->reg_base + PS2_REG_LCTL); > + > + /*Reset FIFO*/ > + rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN > + | PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN > + | PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN; > + > + writel(rval, drvdata->reg_base + PS2_REG_FCTL); > + > + src_clk = clk_get_rate(drvdata->clk); > + /*Set Clock Divider Register*/ > + clk_scdf = DIV_ROUND_UP(src_clk, PS2_SAMPLE_CLK) - 1; > + clk_pcdf = DIV_ROUND_UP(PS2_SAMPLE_CLK, PS2_SCLK) - 1; > + rval = (clk_scdf<<8) | clk_pcdf; > + writel(rval, drvdata->reg_base + PS2_REG_CLKDR); > + > + > + /*Set Global Control Register*/ > + rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER > + | PS2_GCTL_BUSEN; > + > + spin_lock_irqsave(&drvdata->lock, flags); > + writel(rval, drvdata->reg_base + PS2_REG_GCTL); > + spin_unlock_irqrestore(&drvdata->lock, flags); > + > + return 0; > +} > + > +static void sun4i_ps2_close(struct serio *pserio) > +{ > + struct sun4i_ps2data *drvdata = pserio->port_data; > + unsigned long flags; > + > + spin_lock_irqsave(&drvdata->lock, flags); > + /* Disable the PS2 interrupts */ > + writel(0, drvdata->reg_base + PS2_REG_GCTL); > + spin_unlock_irqrestore(&drvdata->lock, flags); I think you want to add synchronize_irq() here to make sure pending interrupt handler runs to completion before you return. > +} > + > +static int sun4i_ps2_write(struct serio *pserio, unsigned char val) > +{ > + unsigned long expire = jiffies + msecs_to_jiffies(10000); > + struct sun4i_ps2data *drvdata; > + > + drvdata = (struct sun4i_ps2data *)pserio->port_data; > + > + do { > + if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) { > + writel(val, drvdata->reg_base + PS2_REG_DATA); > + return 0; > + } > + } while (time_before(jiffies, expire)); > + > + return 0; > +} > + > +static int sun4i_ps2_probe(struct platform_device *pdev) > +{ > + struct resource *res; /* IO mem resources */ > + struct sun4i_ps2data *drvdata; > + struct serio *serio; > + struct device *dev = &pdev->dev; > + unsigned int irq; > + int error; > + > + drvdata = devm_kzalloc(dev, sizeof(struct sun4i_ps2data), GFP_KERNEL); > + serio = kzalloc(sizeof(struct serio), GFP_KERNEL); > + if (!drvdata || !serio) { > + error = -ENOMEM; > + goto err_free_mem; > + } > + > + spin_lock_init(&drvdata->lock); > + > + /* IO */ > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + drvdata->reg_base = devm_ioremap_resource(dev, res); > + if (IS_ERR(drvdata->reg_base)) { > + dev_err(dev, "failed to map registers\n"); > + error = PTR_ERR(drvdata->reg_base); > + goto err_free_mem; > + } > + > + drvdata->clk = devm_clk_get(dev, NULL); > + if (IS_ERR(drvdata->clk)) { > + error = PTR_ERR(drvdata->clk); > + dev_err(dev, "couldn't get clock %d\n", error); > + goto err_free_mem; > + } > + > + error = clk_prepare_enable(drvdata->clk); > + if (error) { > + dev_err(dev, "failed to enable clock %d\n", error); > + goto err_free_mem; > + } > + I think you should explicitly prohibit the device generating interrupts by writing to PS2_ERG_CTRL here. > + serio->id.type = SERIO_8042; > + serio->write = sun4i_ps2_write; > + serio->open = sun4i_ps2_open; > + serio->close = sun4i_ps2_close; > + serio->port_data = drvdata; > + serio->dev.parent = dev; > + strlcpy(serio->name, dev_name(dev), sizeof(serio->name)); > + strlcpy(serio->phys, dev_name(dev), sizeof(serio->phys)); > + > + /* Get IRQ for the device */ > + irq = platform_get_irq(pdev, 0); > + if (!irq) { > + dev_err(dev, "no IRQ found\n"); > + error = -ENXIO; > + goto error_disable_clk; > + } > + > + drvdata->irq = irq; > + drvdata->serio = serio; > + drvdata->dev = dev; > + error = devm_request_threaded_irq(dev, drvdata->irq, > + sun4i_ps2_interrupt, NULL, 0, DRIVER_NAME, drvdata); > + > + if (error) { > + dev_err(drvdata->dev, "Interrupt alloc failed %d:error:%d\n", > + drvdata->irq, error); > + goto error_disable_clk; > + } > + > + serio_register_port(serio); > + platform_set_drvdata(pdev, drvdata); > + > + return 0; /* success */ > + > +error_disable_clk: > + clk_disable_unprepare(drvdata->clk); > + > +err_free_mem: > + kfree(serio); > + return error; > +} > + > +static int sun4i_ps2_remove(struct platform_device *pdev) > +{ > + struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev); > + > + serio_unregister_port(drvdata->serio); > + disable_irq(drvdata->irq); I do not think you need to disable irq here - serio_close will make sure that the device does not generate interrupts. > + > + if (!IS_ERR(drvdata->clk)) > + clk_disable_unprepare(drvdata->clk); > + kfree(drvdata->serio); > + > + return 0; > +} > + > +/* Match table for of_platform binding */ > +static const struct of_device_id sun4i_ps2_match[] = { > + { .compatible = "allwinner,sun4i-a10-ps2", }, > + { }, > +}; > + > +MODULE_DEVICE_TABLE(of, sun4i_ps2_match); > + > +/*platform driver structure*/ I do not think we should keep the obvious comments like this one. > +static struct platform_driver sun4i_ps2_driver = { > + .probe = sun4i_ps2_probe, > + .remove = sun4i_ps2_remove, > + .driver = { > + .name = DRIVER_NAME, > + .of_match_table = sun4i_ps2_match, > + }, > +}; > +module_platform_driver(sun4i_ps2_driver); > + > +MODULE_AUTHOR("Vishnu Patekar "); > +MODULE_AUTHOR("Aaron.maoye "); > +MODULE_DESCRIPTION("Allwinner A10/Sun4i PS/2 driver"); > +MODULE_LICENSE("GPL v2"); > -- > 1.7.9.5 > Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/