[PATCH] Input: add IOC3 serio driver

[PATCH] Input: add IOC3 serio driver

[Thomas Bogendoerfer]

This patch adds a platform driver for supporting keyboard and mouse
interface of SGI IOC3 chips.

Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/input/serio/Kconfig   |  10 ++
 drivers/input/serio/Makefile  |   1 +
 drivers/input/serio/ioc3kbd.c | 183 ++++++++++++++++++++++++++++++++++
 3 files changed, 194 insertions(+)
 create mode 100644 drivers/input/serio/ioc3kbd.c

diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
index f3e18f8ef9ca..373a1646019e 100644
--- a/drivers/input/serio/Kconfig
+++ b/drivers/input/serio/Kconfig
@@ -165,6 +165,16 @@ config SERIO_MACEPS2
 	  To compile this driver as a module, choose M here: the
 	  module will be called maceps2.
 
+config SERIO_SGI_IOC3
+	tristate "SGI IOC3 PS/2 controller"
+	depends on SGI_MFD_IOC3
+	help
+	  Say Y here if you have an SGI Onyx2, SGI Octane or IOC3 PCI card
+	  and you want to attach and use a keyboard, mouse, or both.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ioc3kbd.
+
 config SERIO_LIBPS2
 	tristate "PS/2 driver library"
 	depends on SERIO_I8042 || SERIO_I8042=n
diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
index 67950a5ccb3f..6d97bad7b844 100644
--- a/drivers/input/serio/Makefile
+++ b/drivers/input/serio/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_HIL_MLC)		+= hp_sdc_mlc.o hil_mlc.o
 obj-$(CONFIG_SERIO_PCIPS2)	+= pcips2.o
 obj-$(CONFIG_SERIO_PS2MULT)	+= ps2mult.o
 obj-$(CONFIG_SERIO_MACEPS2)	+= maceps2.o
+obj-$(CONFIG_SERIO_SGI_IOC3)	+= ioc3kbd.o
 obj-$(CONFIG_SERIO_LIBPS2)	+= libps2.o
 obj-$(CONFIG_SERIO_RAW)		+= serio_raw.o
 obj-$(CONFIG_SERIO_AMS_DELTA)	+= ams_delta_serio.o
diff --git a/drivers/input/serio/ioc3kbd.c b/drivers/input/serio/ioc3kbd.c
new file mode 100644
index 000000000000..814ca640732f
--- /dev/null
+++ b/drivers/input/serio/ioc3kbd.c
@@ -0,0 +1,183 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SGI IOC3 PS/2 controller driver for linux
+ *
+ * Copyright (C) 2019 Thomas Bogendoerfer <tbogendoerfer@suse.de>
+ *
+ * Based on code Copyright (C) 2005 Stanislaw Skowronek <skylark@unaligned.org>
+ *               Copyright (C) 2009 Johannes Dickgreber <tanzy@gmx.de>
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/serio.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <asm/sn/ioc3.h>
+
+struct ioc3kbd_data {
+	struct ioc3_serioregs __iomem *regs;
+	struct serio *kbd, *aux;
+	int irq;
+};
+
+static int ioc3kbd_wait(struct ioc3_serioregs __iomem *regs, u32 mask)
+{
+	unsigned long timeout = 0;
+
+	while ((readl(&regs->km_csr) & mask) && (timeout < 250)) {
+		udelay(50);
+		timeout++;
+	}
+	return (timeout >= 250) ? -ETIMEDOUT : 0;
+}
+
+static int ioc3kbd_write(struct serio *dev, u8 val)
+{
+	struct ioc3kbd_data *d = dev->port_data;
+	int ret;
+
+	ret = ioc3kbd_wait(d->regs, KM_CSR_K_WRT_PEND);
+	if (ret)
+		return ret;
+
+	writel(val, &d->regs->k_wd);
+
+	return 0;
+}
+
+static int ioc3aux_write(struct serio *dev, u8 val)
+{
+	struct ioc3kbd_data *d = dev->port_data;
+	int ret;
+
+	ret = ioc3kbd_wait(d->regs, KM_CSR_M_WRT_PEND);
+	if (ret)
+		return ret;
+
+	writel(val, &d->regs->m_wd);
+
+	return 0;
+}
+
+static irqreturn_t ioc3kbd_intr(int itq, void *dev_id)
+{
+	struct ioc3kbd_data *d = dev_id;
+	u32 data_k, data_m;
+
+	data_k = readl(&d->regs->k_rd);
+	data_m = readl(&d->regs->m_rd);
+
+	if (data_k & KM_RD_VALID_0)
+		serio_interrupt(d->kbd, (data_k >> KM_RD_DATA_0_SHIFT) & 0xff,
+				0);
+	if (data_k & KM_RD_VALID_1)
+		serio_interrupt(d->kbd, (data_k >> KM_RD_DATA_1_SHIFT) & 0xff,
+				0);
+	if (data_k & KM_RD_VALID_2)
+		serio_interrupt(d->kbd, (data_k >> KM_RD_DATA_2_SHIFT) & 0xff,
+				0);
+	if (data_m & KM_RD_VALID_0)
+		serio_interrupt(d->aux, (data_m >> KM_RD_DATA_0_SHIFT) & 0xff,
+				0);
+	if (data_m & KM_RD_VALID_1)
+		serio_interrupt(d->aux, (data_m >> KM_RD_DATA_1_SHIFT) & 0xff,
+				0);
+	if (data_m & KM_RD_VALID_2)
+		serio_interrupt(d->aux, (data_m >> KM_RD_DATA_2_SHIFT) & 0xff,
+				0);
+
+	return IRQ_HANDLED;
+}
+
+static int ioc3kbd_probe(struct platform_device *pdev)
+{
+	struct ioc3_serioregs __iomem *regs;
+	struct device *dev = &pdev->dev;
+	struct ioc3kbd_data *d;
+	struct serio *sk, *sa;
+	int irq, ret;
+
+	regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -ENXIO;
+
+	d = devm_kzalloc(dev, sizeof(*d), GFP_KERNEL);
+	if (!d)
+		return -ENOMEM;
+
+	sk = kzalloc(sizeof(*sk), GFP_KERNEL);
+	if (!sk)
+		return -ENOMEM;
+
+	sa = kzalloc(sizeof(*sa), GFP_KERNEL);
+	if (!sa) {
+		kfree(sk);
+		return -ENOMEM;
+	}
+
+	sk->id.type = SERIO_8042;
+	sk->write = ioc3kbd_write;
+	snprintf(sk->name, sizeof(sk->name), "IOC3 keyboard %d", pdev->id);
+	snprintf(sk->phys, sizeof(sk->phys), "ioc3/serio%dkbd", pdev->id);
+	sk->port_data = d;
+	sk->dev.parent = dev;
+
+	sa->id.type = SERIO_8042;
+	sa->write = ioc3aux_write;
+	snprintf(sa->name, sizeof(sa->name), "IOC3 auxiliary %d", pdev->id);
+	snprintf(sa->phys, sizeof(sa->phys), "ioc3/serio%daux", pdev->id);
+	sa->port_data = d;
+	sa->dev.parent = dev;
+
+	d->regs = regs;
+	d->kbd = sk;
+	d->aux = sa;
+	d->irq = irq;
+
+	platform_set_drvdata(pdev, d);
+	serio_register_port(d->kbd);
+	serio_register_port(d->aux);
+
+	ret = request_irq(irq, ioc3kbd_intr, IRQF_SHARED, "ioc3-kbd", d);
+	if (ret) {
+		dev_err(dev, "could not request IRQ %d\n", irq);
+		serio_unregister_port(d->kbd);
+		serio_unregister_port(d->aux);
+		return ret;
+	}
+
+	/* enable ports */
+	writel(KM_CSR_K_CLAMP_3 | KM_CSR_M_CLAMP_3, &regs->km_csr);
+
+	return 0;
+}
+
+static int ioc3kbd_remove(struct platform_device *pdev)
+{
+	struct ioc3kbd_data *d = platform_get_drvdata(pdev);
+
+	free_irq(d->irq, d);
+	serio_unregister_port(d->kbd);
+	serio_unregister_port(d->aux);
+	return 0;
+}
+
+static struct platform_driver ioc3kbd_driver = {
+	.probe          = ioc3kbd_probe,
+	.remove         = ioc3kbd_remove,
+	.driver = {
+		.name = "ioc3-kbd",
+	},
+};
+module_platform_driver(ioc3kbd_driver);
+
+MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfer@suse.de>");
+MODULE_DESCRIPTION("SGI IOC3 serio driver");
+MODULE_LICENSE("GPL");
-- 
2.24.1

Re: [PATCH] Input: add IOC3 serio driver

[Dmitry Torokhov]

Hi Thomas,

On Wed, Jan 15, 2020 at 01:59:50PM +0100, Thomas Bogendoerfer wrote:
> +
> +	platform_set_drvdata(pdev, d);
> +	serio_register_port(d->kbd);
> +	serio_register_port(d->aux);
> +
> +	ret = request_irq(irq, ioc3kbd_intr, IRQF_SHARED, "ioc3-kbd", d);

I just realized something - serio ports are registered asynchronously,
and therefore may not be ready when you request IRQ which may fire
immediately. To solve this issue serio core allows to specify start()
method that is called after serio port has been registered. In this
method you can set "exist" flag associated with either kbd or aux port,
and check these flags in your interrupt routine before deciding whether
you can forward the received data to appropriate port via
serio_interrupt().

Please see i8042_start() for example of use.

Thanks.

-- 
Dmitry