From: "Benoît Thébaudeau" <benoit@wsystem.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 4/4] mx25pdk: Set the eSDHC PER clock to 48 MHz
Date: Wed, 3 May 2017 11:59:06 +0200 [thread overview]
Message-ID: <1493805546-3567-4-git-send-email-benoit@wsystem.com> (raw)
In-Reply-To: <1493805546-3567-1-git-send-email-benoit@wsystem.com>
The maximum SD clock frequency in High Speed mode is 50 MHz. This change
makes it possible to get 48 MHz from the USB PLL (240 MHz / 5 / 1)
instead of the previous 33.25 MHz from the AHB clock (133 MHz / 2 / 2).
Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
---
board/freescale/mx25pdk/mx25pdk.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/board/freescale/mx25pdk/mx25pdk.c b/board/freescale/mx25pdk/mx25pdk.c
index 788d3c3..cab769c 100644
--- a/board/freescale/mx25pdk/mx25pdk.c
+++ b/board/freescale/mx25pdk/mx25pdk.c
@@ -175,6 +175,12 @@ int board_mmc_init(bd_t *bis)
imx_iomux_v3_setup_multiple_pads(sdhc1_pads, ARRAY_SIZE(sdhc1_pads));
+ /*
+ * Set the eSDHC1 PER clock to the maximum frequency lower than or equal
+ * to 50 MHz that can be obtained, which requires to use UPLL as the
+ * clock source. This actually gives 48 MHz.
+ */
+ imx_set_perclk(MXC_ESDHC1_CLK, true, 50000000);
esdhc_cfg[0].sdhc_clk = mxc_get_clock(MXC_ESDHC1_CLK);
return fsl_esdhc_initialize(bis, &esdhc_cfg[0]);
}
--
2.7.4
next prev parent reply other threads:[~2017-05-03 9:59 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-03 9:59 [U-Boot] [PATCH 1/4] mmc: fsl_esdhc: Allow all supported prescaler values Benoît Thébaudeau
2017-05-03 9:59 ` [U-Boot] [PATCH 2/4] mx25: Fix imx_get_perclk() Benoît Thébaudeau
2017-05-29 11:18 ` Fabio Estevam
2017-05-31 8:50 ` Stefano Babic
2017-05-03 9:59 ` [U-Boot] [PATCH 3/4] mx25: Add function to set PER clocks Benoît Thébaudeau
2017-05-29 11:19 ` Fabio Estevam
2017-05-31 8:50 ` Stefano Babic
2017-05-03 9:59 ` Benoît Thébaudeau [this message]
2017-05-29 11:20 ` [U-Boot] [PATCH 4/4] mx25pdk: Set the eSDHC PER clock to 48 MHz Fabio Estevam
2017-05-31 8:50 ` Stefano Babic
2017-05-29 11:17 ` [U-Boot] [PATCH 1/4] mmc: fsl_esdhc: Allow all supported prescaler values Fabio Estevam
2017-05-31 8:50 ` Stefano Babic
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