<div dir="ltr"><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Oct 12, 2016 at 5:41 PM, Jaghathiswari Rankappagounder Natarajan <span dir="ltr"><<a href="mailto:jaghu@google.com" target="_blank">jaghu@google.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Platform driver to periodically update the display on the POST card.<br>
POST card hardware assumed is 74HC164 wired to two 7-segment displays.<br>
<br>
Signed-off-by: Jaghathiswari Rankappagounder Natarajan <<a href="mailto:jaghu@google.com">jaghu@google.com</a>><br>
---<br>
drivers/misc/Kconfig | 6 ++<br>
drivers/misc/Makefile | 1 +<br>
drivers/misc/update-postcard.c | 219 ++++++++++++++++++++++++++++++<wbr>+++++++++++<br>
drivers/misc/update-postcard.h | 1 +<br>
4 files changed, 227 insertions(+)<br>
create mode 100644 drivers/misc/update-postcard.c<br>
create mode 100644 drivers/misc/update-postcard.h<br>
<br>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig<br>
index 4617ddc..d65b83f 100644<br>
--- a/drivers/misc/Kconfig<br>
+++ b/drivers/misc/Kconfig<br>
@@ -804,6 +804,12 @@ config PANEL_BOOT_MESSAGE<br>
An empty message will only clear the display at driver init time. Any other<br>
printf()-formatted message is valid with newline and escape codes.<br>
<br>
+config ASPEED_UPDATE_POSTCARD<br>
+ tristate "Platform driver to update POST card"<br>
+ help<br>
+ Support to periodically update display on the POST card. The POST card<br>
+ hardware assumed is 74HC164 wired to two 7-segment displays.<br>
+<br></blockquote><div><br></div><div>Nothing about this driver is associated with Aspeed. UPDATE_POSTCARD reads to me as describing an action, not a device. Maybe SEVEN_SEGMENT_DISPLAY?</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
config ASPEED_BT_IPMI_HOST<br>
tristate "BT IPMI host driver"<br>
help<br>
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile<br>
index 724861b..730c6c2 100644<br>
--- a/drivers/misc/Makefile<br>
+++ b/drivers/misc/Makefile<br>
@@ -57,4 +57,5 @@ obj-$(CONFIG_ECHO) += echo/<br>
obj-$(CONFIG_VEXPRESS_SYSCFG) += vexpress-syscfg.o<br>
obj-$(CONFIG_CXL_BASE) += cxl/<br>
obj-$(CONFIG_PANEL) += panel.o<br>
+obj-$(CONFIG_ASPEED_UPDATE_<wbr>POSTCARD) += update-postcard.o<br>
obj-$(CONFIG_ASPEED_BT_IPMI_<wbr>HOST) += bt-host.o<br>
diff --git a/drivers/misc/update-<wbr>postcard.c b/drivers/misc/update-<wbr>postcard.c<br>
new file mode 100644<br>
index 0000000..3516c24<br>
--- /dev/null<br>
+++ b/drivers/misc/update-<wbr>postcard.c<br>
@@ -0,0 +1,219 @@<br>
+/* Platform driver to periodically update the display on the POST card.<br>
+ * POST card hardware assumed is 74HC164 wired to two 7-segment displays.<br>
+ */<br>
+<br>
+#include <linux/kernel.h><br>
+#include <linux/module.h><br>
+#include <linux/timer.h><br>
+#include <linux/jiffies.h><br>
+#include <linux/sizes.h><br>
+#include <linux/map_to_7segment.h><br>
+#include <linux/io.h><br>
+#include <linux/delay.h><br>
+#include <linux/uaccess.h><br>
+#include <linux/mutex.h><br>
+#include <linux/of_platform.h><br>
+#include <linux/gpio/consumer.h><br>
+<br>
+#define POST_CODE_UPDATE_INTVL 1000<br>
+<br>
+#define MAX_PC_SIZE 3<br>
+<br>
+#define LED_DOT 0x01<br>
+<br>
+#define CLOCK_GPIO_NAME "clk"<br>
+#define DATA_GPIO_NAME "data"<br>
+#define CLEAR_GPIO_NAME "clr"<br>
+<br>
+static struct mutex mutex;<br>
+<br>
+static struct timer_list update_timer;<br>
+<br>
+static char curr_postcode[3];<br>
+static u8 pc_valid;<br>
+<br></blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">+static struct gpio_desc *clk_gpio;<br>
+static struct gpio_desc *data_gpio;<br>
+static struct gpio_desc *clr_gpio;<br></blockquote><div><br></div><div>I realize there should really only ever be one of these in a system but static data members in modules bug me. I'd much rather see all this configuration and these buffers in a struct that is saved with platform_set_drvdata().</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
+<br>
+/*<br>
+ * 0 1 2 3 4 5 6 7 8 9 A B C D E F<br>
+ * _ _ _ _ _ _ _ _ _ _ _ _<br>
+ * | | | _| _| |_| |_ |_ | |_| |_| |_| |_ | _| |_ |_<br>
+ * |_| | |_ _| | _| |_| | |_| | | | |_| |_ |_| |_ |<br>
+ *<br>
+ * data[7:1] = led[a:g]<br>
+ * lookup table used for both bytes of lpc post code and lower byte of<br>
+ * bmc post code<br>
+ */<br>
+const u8 seven_seg_bits[] = {<br>
+ 0xFC, 0x60, 0xDA, 0xF2, 0x66, 0xB6, 0xBE, 0xE0,<br>
+ 0xFE, 0xF6, 0xEE, 0x3E, 0x9C, 0x7A, 0x9E, 0x8E<br>
+ };<br>
+<br>
+/*<br>
+ * 0 1 2 3 4 5 6 7 8 9 A B C D E F<br>
+ * _ _ _ _ _<br>
+ * | |_ |_| |_ _ _ _ _ _ _ _ |_ _| _| | |<br>
+ * |_ |_ | | _| |_| |_| | |<br>
+ *<br>
+ * data[7:1] = led[a:g]<br>
+ * lookup table used for higher byte of bmc post code<br>
+ */<br>
+const u8 special_seven_seg_bits[] = {<br>
+ 0x00, 0x9C, 0x1E, 0xCE, 0x8E, 0x02, 0x02, 0x02,<br>
+ 0x02, 0x02, 0x02, 0x02, 0xB6, 0x7A, 0x7A, 0xEC<br>
+ };<br>
+<br>
+void update_postcode(char *buf)<br>
+{<br>
+ mutex_lock(&mutex);<br>
+ strncpy(curr_postcode, buf, sizeof(curr_postcode));<br>
+ mutex_unlock(&mutex);<br>
+ pc_valid = 1;<br>
+}<br>
+EXPORT_SYMBOL(update_<wbr>postcode);<br>
+<br>
+/* convert postcode to led pattern<br>
+ * 7-bits used for each 7-seg display and<br>
+ * 1 bit used for the 'dot' on both digits.<br>
+ *<br>
+ * @param N/A<br>
+ * @return N/A<br>
+ */<br>
+static u16 postcode_to_led_signal(void)<br>
+{<br>
+ u8 low_display;<br>
+ u8 high_display;<br>
+ u16 led_value;<br>
+ char buf[3];<br>
+<br>
+ mutex_lock(&mutex);<br>
+ strncpy(buf, curr_postcode, sizeof(buf));<br>
+ mutex_unlock(&mutex);<br>
+<br>
+ low_display = seven_seg_bits[hex_to_bin(buf[<wbr>2])];<br>
+<br>
+ high_display = (buf[0] == '1') ?<br>
+ special_seven_seg_bits[hex_to_<wbr>bin(buf[1])] :<br>
+ seven_seg_bits[hex_to_bin(buf[<wbr>1])];<br>
+<br>
+ led_value = low_display | (high_display << 8);<br>
+ if (buf[0] == '1') {<br>
+ led_value |= LED_DOT | (LED_DOT << 8);<br>
+ }<br>
+<br>
+ return led_value;<br>
+}<br>
+<br>
+static void update_sgpio(void)<br>
+{<br>
+ u16 led_signal;<br>
+ int i;<br>
+<br>
+ /* Convert two bytes of post code to 16 bit led pattern */<br>
+ led_signal = postcode_to_led_signal();<br>
</blockquote><div><br></div><div>Why do you wait until the display update to convert the string to the LED bit pattern? For that matter, why does update_postcode() take a string at all? If you can only display at most a 16-bit number, take a u16 and have the caller deal with whatever processing they need.</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">+<br>
+ /* Set the clear signal to low */<br>
+ gpiod_set_value(clr_gpio, 0);<br>
+ udelay(1);<br>
+ /* Set the clear clear to high */<br>
+ gpiod_set_value(clr_gpio, 1);<br>
+ udelay(1);<br>
+<br>
+ /* Bitbang the 16 bit led pattern<br>
+ * 7-bits used for each 7-seg display<br>
+ * 1 bit used for the 'dot' on both digits<br>
+ */<br>
+ for (i = 0; i < 16; i++) {<br>
+ if (led_signal & 0x01) {<br>
+ /* Set the data signal to high */<br>
+ gpiod_set_value(data_gpio, 1);<br>
+ } else {<br>
+ /* Set the data signal to low */<br>
+ gpiod_set_value(data_gpio, 0);<br>
+ }<br>
+ udelay(1);<br>
+<br>
+ /* Set the clock signal to low */<br>
+ gpiod_set_value(clk_gpio, 0);<br>
+ udelay(1);<br>
+ /* Set the clock signal to high */<br>
+ gpiod_set_value(clk_gpio, 1);<br>
+ udelay(1);<br>
+<br>
+ led_signal >>= 1;<br>
+ }<br>
+}<br>
+<br>
+static void update_timer_handler(unsigned long data)<br>
+{<br>
+ if (pc_valid == 1) {<br></blockquote><div><br></div><div>Is this to avoid the time after the driver is register until update_postcode() is called the first time? Is there an API for clearing the display?</div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
+ update_sgpio();<br>
+ }<br>
+ mod_timer(&update_timer,<br>
+ jiffies + msecs_to_jiffies(POST_CODE_<wbr>UPDATE_INTVL));<br>
+}<br>
+<br>
+static const struct of_device_id of_postcard_match[] = {<br>
+ { .compatible = "postcard-display" },<br>
+ {},<br>
+};<br>
+<br>
+MODULE_DEVICE_TABLE(of, of_postcard_match);<br>
+<br>
+static int postcard_probe(struct platform_device *pdev)<br>
+{<br>
+ int result;<br>
+ struct device *dev = &pdev->dev;<br>
+<br>
+ /* Requesting the clock gpio */<br>
+ clk_gpio = devm_gpiod_get(dev, CLOCK_GPIO_NAME,<br>
+ GPIOD_OUT_HIGH);<br>
+ if (IS_ERR(clk_gpio))<br>
+ return PTR_ERR(data_gpio);<br>
+<br>
+ /* Requesting the data gpio */<br>
+ data_gpio = devm_gpiod_get(dev, DATA_GPIO_NAME,<br>
+ GPIOD_OUT_HIGH);<br>
+ if (IS_ERR(data_gpio))<br>
+ return PTR_ERR(data_gpio);<br>
+<br>
+ /* Requesting the clear gpio */<br>
+ clr_gpio = devm_gpiod_get(dev, CLEAR_GPIO_NAME,<br>
+ GPIOD_OUT_HIGH);<br>
+ if (IS_ERR(clr_gpio))<br>
+ return PTR_ERR(clr_gpio);<br>
+<br>
+ /* Start timer to update post code every second */<br>
+ setup_timer(&update_timer, update_timer_handler, 0);<br>
+ result = mod_timer(&update_timer,<br>
+ jiffies + msecs_to_jiffies(POST_CODE_<wbr>UPDATE_INTVL));<br>
+<br>
+ if (result)<br>
+ return result;<br>
+<br>
+ mutex_init(&mutex);<br>
+<br>
+ return 0;<br>
+}<br>
+<br>
+static void postcard_remove(struct platform_device *pdev)<br>
+{<br>
+ del_timer(&update_timer);<br>
+}<br>
+<br>
+static struct platform_driver postcard_display_driver = {<br>
+ .probe = postcard_probe,<br>
+ .shutdown = postcard_remove,<br>
+ .driver = {<br>
+ .name = "postcard-display",<br>
+ .of_match_table = of_postcard_match,<br>
+ },<br>
+};<br>
+<br>
+module_platform_driver(<wbr>postcard_display_driver);</blockquote><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
+<br>
+MODULE_LICENSE("GPL");<br>
+MODULE_AUTHOR("Jaghathiswari Rankappagounder Natarajan <<a href="mailto:jaghu@google.com">jaghu@google.com</a>>");<br>
+MODULE_DESCRIPTION("Post card display update driver");<br>
diff --git a/drivers/misc/update-<wbr>postcard.h b/drivers/misc/update-<wbr>postcard.h<br>
new file mode 100644<br>
index 0000000..ef82e9091d<br>
--- /dev/null<br>
+++ b/drivers/misc/update-<wbr>postcard.h<br>
@@ -0,0 +1 @@<br>
+void update_postcode(char *buf);<br>
--<br>
2.8.0.rc3.226.g39d4020<br>
<br>
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</blockquote></div><br></div></div>