diff options
Diffstat (limited to 'target/linux/xburst/patches-3.18/005-RTC-JZ4740-Init-the-regulator-register-on-startup.patch')
| -rw-r--r-- | target/linux/xburst/patches-3.18/005-RTC-JZ4740-Init-the-regulator-register-on-startup.patch | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/target/linux/xburst/patches-3.18/005-RTC-JZ4740-Init-the-regulator-register-on-startup.patch b/target/linux/xburst/patches-3.18/005-RTC-JZ4740-Init-the-regulator-register-on-startup.patch new file mode 100644 index 0000000..f38483a --- /dev/null +++ b/target/linux/xburst/patches-3.18/005-RTC-JZ4740-Init-the-regulator-register-on-startup.patch @@ -0,0 +1,55 @@ +From f05b1ecd7e4fde7e69320a4b7be461636e982991 Mon Sep 17 00:00:00 2001 +From: Paul Cercueil <paul@crapouillou.net> +Date: Thu, 13 Sep 2012 00:09:20 +0200 +Subject: [PATCH 5/7] RTC: JZ4740: Init the "regulator" register on startup. + +This register controls the accuracy of the RTC. uC/OS-II use +the RTC as a 100Hz clock, and writes a completely wrong value +on that register, that we have to overwrite if we want a working +real-time clock. + +Signed-off-by: Paul Cercueil <paul@crapouillou.net> +--- + drivers/rtc/rtc-jz4740.c | 17 +++++++++++++++++ + 1 file changed, 17 insertions(+) + +--- a/drivers/rtc/rtc-jz4740.c ++++ b/drivers/rtc/rtc-jz4740.c +@@ -15,6 +15,7 @@ + */ + + #include <linux/io.h> ++#include <linux/clk.h> + #include <linux/kernel.h> + #include <linux/module.h> + #include <linux/platform_device.h> +@@ -216,6 +217,7 @@ static int jz4740_rtc_probe(struct platf + struct jz4740_rtc *rtc; + uint32_t scratchpad; + struct resource *mem; ++ struct clk *rtc_clk; + + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); + if (!rtc) +@@ -263,6 +265,21 @@ static int jz4740_rtc_probe(struct platf + } + } + ++ rtc_clk = clk_get(&pdev->dev, "rtc"); ++ if (IS_ERR(rtc_clk)) { ++ dev_err(&pdev->dev, "Failed to get RTC clock\n"); ++ return PTR_ERR(rtc_clk); ++ } ++ ++ /* TODO: initialize the ADJC bits (25:16) to fine-tune ++ * the accuracy of the RTC */ ++ ret = jz4740_rtc_reg_write(rtc, JZ_REG_RTC_REGULATOR, ++ (clk_get_rate(rtc_clk) - 1) & 0xffff); ++ clk_put(rtc_clk); ++ ++ if (ret) ++ dev_warn(&pdev->dev, "Could not update RTC regulator register\n"); ++ + return 0; + } + |