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Subject[PATCH 1/2] mfd: micon: Add Buffalo Kurobox Pro, Terastation II Pro/Live driver
Date
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.

Signed-off-by: Florian Fainelli <f.fainelli@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 */
--
2.9.3
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