On Wed, 28 Dec 2016, Florian Fainelli wrote:
> This driver is currently only used to reboot the devices, but the
> microcontroller hanging off UART1 on the Buffalo Kurobox Pro and
> Terastation II Pro/Live is capable of a lot more than that, which we
> will support in subsequent patches. For now, just add the reboot
> functionality to make the kernel reboot correctly.
This is not an MFD driver. You have written a UART driver.
Please relocate it to drivers/char/tty/serial.
> Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
> ---
> drivers/mfd/Kconfig | 8 ++
> drivers/mfd/Makefile | 2 +
> drivers/mfd/micon.c | 204
> ++++++++++++++++++++++++++++++++++++
> include/linux/platform_data/micon.h | 10 ++
> 4 files changed, 224 insertions(+)
> create mode 100644 drivers/mfd/micon.c
> create mode 100644 include/linux/platform_data/micon.h
>
> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 4ce3b6f11830..e7df3d29351c 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -352,6 +352,14 @@ config MFD_MX25_TSADC
> i.MX25 processors. They consist of a conversion queue for general
> purpose ADC and a queue for Touchscreens.
>
> +config MFD_MICON
> + bool "Buffalo Kurobox Pro/Terastation II Pro/Live MCU interface"
> + depends on PLAT_ORION
> + help
> + Enables support for the UART1 attached micro controller on Buffalo
> + Kurobox Pro and Terastation II Pro/Live NAS devices. Used for
> + machine restart.
> +
> config MFD_HI6421_PMIC
> tristate "HiSilicon Hi6421 PMU/Codec IC"
> depends on OF
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index dda4d4f73ad7..61a226878129 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -94,6 +94,8 @@ obj-$(CONFIG_MFD_MC13XXX) += mc13xxx-core.o
> obj-$(CONFIG_MFD_MC13XXX_SPI) += mc13xxx-spi.o
> obj-$(CONFIG_MFD_MC13XXX_I2C) += mc13xxx-i2c.o
>
> +obj-$(CONFIG_MFD_MICON) += micon.o
> +
> obj-$(CONFIG_MFD_CORE) += mfd-core.o
>
> obj-$(CONFIG_EZX_PCAP) += ezx-pcap.o
> diff --git a/drivers/mfd/micon.c b/drivers/mfd/micon.c
> new file mode 100644
> index 000000000000..fe56abdc0160
> --- /dev/null
> +++ b/drivers/mfd/micon.c
> @@ -0,0 +1,204 @@
> +/*
> + * Buffalo Kurobox/Terastation Pro II specific power off method via
> + * UART1-attached microcontroller
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License
> + * as published by the Free Software Foundation; either version
> + * 2 of the License, or (at your option) any later version.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/io.h>
> +#include <linux/delay.h>
> +#include <linux/platform_device.h>
> +#include <linux/platform_data/micon.h>
> +#include <linux/serial_reg.h>
> +#include <linux/notifier.h>
> +#include <linux/reboot.h>
> +
> +struct micon_priv {
> + struct device *dev;
> + void __iomem *base;
> + int tclk;
> + struct notifier_block nb;
> +};
> +
> +#define UART1_REG(x) ((UART_##x) << 2)
> +
> +static int miconread(struct micon_priv *priv, unsigned char *buf, int count)
> +{
> + int i;
> + int timeout;
> +
> + for (i = 0; i < count; i++) {
> + timeout = 10;
> +
> + while (!(readl(priv->base + UART1_REG(LSR)) & UART_LSR_DR)) {
> + if (--timeout == 0)
> + break;
> + udelay(1000);
> + }
> +
> + if (timeout == 0)
> + break;
> + buf[i] = readl(priv->base + UART1_REG(RX));
> + }
> +
> + /* return read bytes */
> + return i;
> +}
> +
> +static int miconwrite(struct micon_priv *priv, const unsigned char *buf,
> + int count)
> +{
> + int i = 0;
> +
> + while (count--) {
> + while (!(readl(priv->base + UART1_REG(LSR)) & UART_LSR_THRE))
> + barrier();
> + writel(buf[i++], priv->base + UART1_REG(TX));
> + }
> +
> + return 0;
> +}
> +
> +static int miconsend(struct micon_priv *priv, const unsigned char *data,
> + int count)
> +{
> + int i;
> + unsigned char checksum = 0;
> + unsigned char recv_buf[40];
> + unsigned char send_buf[40];
> + unsigned char correct_ack[3];
> + int retry = 2;
> +
> + /* Generate checksum */
> + for (i = 0; i < count; i++)
> + checksum -= data[i];
> +
> + do {
> + /* Send data */
> + miconwrite(priv, data, count);
> +
> + /* send checksum */
> + miconwrite(priv, &checksum, 1);
> +
> + if (miconread(priv, recv_buf, sizeof(recv_buf)) <= 3) {
> + dev_err(priv->dev, ">%s: receive failed.\n", __func__);
> +
> + /* send preamble to clear the receive buffer */
> + memset(&send_buf, 0xff, sizeof(send_buf));
> + miconwrite(priv, send_buf, sizeof(send_buf));
> +
> + /* make dummy reads */
> + mdelay(100);
> + miconread(priv, recv_buf, sizeof(recv_buf));
> + } else {
> + /* Generate expected ack */
> + correct_ack[0] = 0x01;
> + correct_ack[1] = data[1];
> + correct_ack[2] = 0x00;
> +
> + /* checksum Check */
> + if ((recv_buf[0] + recv_buf[1] + recv_buf[2] +
> + recv_buf[3]) & 0xFF) {
> + dev_err(priv->dev, ">%s: Checksum Error : "
> + "Received data[%02x, %02x, %02x, %02x]"
> + "\n", __func__, recv_buf[0],
> + recv_buf[1], recv_buf[2], recv_buf[3]);
> + } else {
> + /* Check Received Data */
> + if (correct_ack[0] == recv_buf[0] &&
> + correct_ack[1] == recv_buf[1] &&
> + correct_ack[2] == recv_buf[2]) {
> + /* Interval for next command */
> + mdelay(10);
> +
> + /* Receive ACK */
> + return 0;
> + }
> + }
> + /* Received NAK or illegal Data */
> + dev_err(priv->dev, ">%s: Error : NAK or Illegal Data "
> + "Received\n", __func__);
> + }
> + } while (retry--);
> +
> + /* Interval for next command */
> + mdelay(10);
> +
> + return -1;
> +}
> +
> +static int restart_handler(struct notifier_block *this,
> + unsigned long code, void *cmd)
> +{
> + struct micon_priv *priv = container_of(this, struct micon_priv, nb);
> +
> + const unsigned char watchdogkill[] = {0x01, 0x35, 0x00};
> + const unsigned char shutdownwait[] = {0x00, 0x0c};
> + const unsigned char poweroff[] = {0x00, 0x06};
> + /* 38400 baud divisor */
> + unsigned int divisor = ((priv->tclk + (8 * 38400)) / (16 * 38400));
> +
> + if (code != SYS_DOWN && code != SYS_HALT)
> + return NOTIFY_DONE;
> +
> + dev_info(priv->dev, "%s: triggering power-off...\n", __func__);
> +
> + /* hijack uart1 and reset into sane state (38400,8n1,even parity) */
> + writel(0x83, priv->base + UART1_REG(LCR));
> + writel(divisor & 0xff, priv->base + UART1_REG(DLL));
> + writel((divisor >> 8) & 0xff, priv->base + UART1_REG(DLM));
> + writel(0x1b, priv->base + UART1_REG(LCR));
> + writel(0x00, priv->base + UART1_REG(IER));
> + writel(0x07, priv->base + UART1_REG(FCR));
> + writel(0x00, priv->base + UART1_REG(MCR));
> +
> + /* Send the commands to shutdown the Terastation Pro II */
> + miconsend(priv, watchdogkill, sizeof(watchdogkill));
> + miconsend(priv, shutdownwait, sizeof(shutdownwait));
> + miconsend(priv, poweroff, sizeof(poweroff));
> +
> + return NOTIFY_DONE;
> +}
> +
> +static int micon_probe(struct platform_device *pdev)
> +{
> + struct micon_platform_data *pdata = pdev->dev.platform_data;
> + struct micon_priv *priv;
> + struct resource *r;
> + int ret;
> +
> + if (!pdata)
> + return -ENODEV;
> +
> + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + priv->dev = &pdev->dev;
> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +
> + /* Don't request exclusive access since 8250 may also utilize this
> + * resource
> + */
> + priv->base = devm_ioremap(&pdev->dev, r->start, resource_size(r));
> + if (IS_ERR(priv->base))
> + return -ENOMEM;
> +
> + priv->tclk = pdata->tclk;
> +
> + priv->nb.notifier_call = restart_handler;
> +
> + return register_reboot_notifier(&priv->nb);
> +}
> +
> +static struct platform_driver micon_driver = {
> + .probe = micon_probe,
> + .driver = {
> + .name = MICON_NAME,
> + },
> +};
> +builtin_platform_driver(micon_driver);
> diff --git a/include/linux/platform_data/micon.h
> b/include/linux/platform_data/micon.h
> new file mode 100644
> index 000000000000..67dbaad5dfaa
> --- /dev/null
> +++ b/include/linux/platform_data/micon.h
> @@ -0,0 +1,10 @@
> +#ifndef __MICON_PDATA_H
> +#define __MICON_PDATA_H
> +
> +#define MICON_NAME "micon"
> +
> +struct micon_platform_data {
> + int tclk;
> +};
> +
> +#endif /* __MICON_PDATA_H */
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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