From a8040053087f6e87318af6a83f40da57bc5fd374 Mon Sep 17 00:00:00 2001
From: Giovanni Di Sirio <gdisirio@gmail.com>
Date: Tue, 25 Apr 2017 07:43:13 +0000
Subject: [PATCH] Power saving mode for SDMMCv1 driver.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@10176 35acf78f-673a-0410-8e92-d51de3d6d3f4
---
 os/hal/ports/STM32/LLD/SDMMCv1/hal_sdc_lld.c | 19 +++++++++++++++++--
 os/hal/ports/STM32/LLD/SDMMCv1/hal_sdc_lld.h |  6 ++++++
 readme.txt                                   |  1 +
 3 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/os/hal/ports/STM32/LLD/SDMMCv1/hal_sdc_lld.c b/os/hal/ports/STM32/LLD/SDMMCv1/hal_sdc_lld.c
index d22fb31d6..791be5750 100644
--- a/os/hal/ports/STM32/LLD/SDMMCv1/hal_sdc_lld.c
+++ b/os/hal/ports/STM32/LLD/SDMMCv1/hal_sdc_lld.c
@@ -543,14 +543,29 @@ void sdc_lld_set_data_clk(SDCDriver *sdcp, sdcbusclk_t clk) {
 #if 0
   if (SDC_CLK_50MHz == clk) {
     sdcp->sdmmc->CLKCR = (sdcp->sdmmc->CLKCR & 0xFFFFFF00U) |
+#if STM32_SDC_SDMMC_PWRSAV
+                         SDMMC_CLKDIV_HS | SDMMC_CLKCR_BYPASS |
+                         SDMMC_CLKCR_PWRSAV;
+#else
                          SDMMC_CLKDIV_HS | SDMMC_CLKCR_BYPASS;
+#endif
   }
-  else
+  else {
+#if STM32_SDC_SDMMC_PWRSAV
+    sdcp->sdmmc->CLKCR = (sdcp->sdmmc->CLKCR & 0xFFFFFF00U) | SDMMC_CLKDIV_HS |
+                         SDMMC_CLKCR_PWRSAV;
+#else
     sdcp->sdmmc->CLKCR = (sdcp->sdmmc->CLKCR & 0xFFFFFF00U) | SDMMC_CLKDIV_HS;
+#endif
+  }
 #else
   (void)clk;
 
-  sdcp->sdmmc->CLKCR = (sdcp->sdmmc->CLKCR & 0xFFFFFF00U) | SDMMC_CLKDIV_HS;
+#if STM32_SDC_SDMMC_PWRSAV
+#else
+  sdcp->sdmmc->CLKCR = (sdcp->sdmmc->CLKCR & 0xFFFFFF00U) | SDMMC_CLKDIV_HS |
+                       SDMMC_CLKCR_PWRSAV;
+#endif
 #endif
 }
 
diff --git a/os/hal/ports/STM32/LLD/SDMMCv1/hal_sdc_lld.h b/os/hal/ports/STM32/LLD/SDMMCv1/hal_sdc_lld.h
index 4479a1c5b..9f4490da3 100644
--- a/os/hal/ports/STM32/LLD/SDMMCv1/hal_sdc_lld.h
+++ b/os/hal/ports/STM32/LLD/SDMMCv1/hal_sdc_lld.h
@@ -84,6 +84,12 @@
  */
 #if !defined(STM32_SDC_SDMMC_CLOCK_DELAY) || defined(__DOXYGEN__)
 #define STM32_SDC_SDMMC_CLOCK_DELAY         10
+
+/**
+ * @brief   Card clock power saving enable.
+ */
+#if !defined(STM32_SDC_SDMMC_PWRSAV) || defined(__DOXYGEN__)
+#define STM32_SDC_SDMMC_PWRSAV              TRUE
 #endif
 
 /**
diff --git a/readme.txt b/readme.txt
index a1162999f..ddd88ccbf 100644
--- a/readme.txt
+++ b/readme.txt
@@ -88,6 +88,7 @@
 *****************************************************************************
 
 *** Next ***
+- HAL: Added clock power saving switch to STM32 SDMMCv1 driver, default is on.
 - RT:  Added safe versions of the time conversion functions, the new versions
        are prefixed with LL_ and use an internal 64 bits representation and
        assertions for overflow conditions.