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Subject[PATCH 3/4] mmc: sdhci-of-arasan: Add support for DLL reset for ZynqMP platforms
Date
The DLL resets are required while executing the auto tuning procedure in
ZynqMP. This patch adds code to support the same.

Signed-off-by: Manish Narani <manish.narani@xilinx.com>
---
drivers/mmc/host/sdhci-of-arasan.c | 46 ++++++++++++++++++++++++++++++
1 file changed, 46 insertions(+)

diff --git a/drivers/mmc/host/sdhci-of-arasan.c b/drivers/mmc/host/sdhci-of-arasan.c
index e49b44b4d82e..39176ab5ca1f 100644
--- a/drivers/mmc/host/sdhci-of-arasan.c
+++ b/drivers/mmc/host/sdhci-of-arasan.c
@@ -757,6 +757,50 @@ static const struct clk_ops zynqmp_sampleclk_ops = {
.set_phase = sdhci_zynqmp_sampleclk_set_phase,
};

+static void arasan_zynqmp_dll_reset(struct sdhci_host *host, u32 deviceid)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
+ struct sdhci_arasan_zynqmp_clk_data *zynqmp_clk_data =
+ sdhci_arasan->clk_data.clk_of_data;
+ const struct zynqmp_eemi_ops *eemi_ops = zynqmp_clk_data->eemi_ops;
+ u16 clk;
+
+ clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+ clk &= ~(SDHCI_CLOCK_CARD_EN | SDHCI_CLOCK_INT_EN);
+ sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+ /* Issue DLL Reset */
+ eemi_ops->ioctl(deviceid, IOCTL_SD_DLL_RESET,
+ PM_DLL_RESET_PULSE, 0, NULL);
+
+ clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+
+ sdhci_enable_clk(host, clk);
+}
+
+static int arasan_zynqmp_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_arasan_data *sdhci_arasan = sdhci_pltfm_priv(pltfm_host);
+ struct clk_hw *hw = &sdhci_arasan->clk_data.sdcardclk_hw;
+ const char *clk_name = clk_hw_get_name(hw);
+ u32 device_id = !strcmp(clk_name, "clk_out_sd0") ? NODE_SD_0 :
+ NODE_SD_1;
+ int err;
+
+ arasan_zynqmp_dll_reset(host, device_id);
+
+ err = sdhci_execute_tuning(mmc, opcode);
+ if (err)
+ return err;
+
+ arasan_zynqmp_dll_reset(host, device_id);
+
+ return 0;
+}
+
/**
* sdhci_arasan_update_clockmultiplier - Set corecfg_clockmultiplier
*
@@ -1247,6 +1291,8 @@ static int sdhci_arasan_probe(struct platform_device *pdev)

zynqmp_clk_data->eemi_ops = eemi_ops;
sdhci_arasan->clk_data.clk_of_data = zynqmp_clk_data;
+ host->mmc_host_ops.execute_tuning =
+ arasan_zynqmp_execute_tuning;
}

arasan_dt_parse_clk_phases(&pdev->dev, &sdhci_arasan->clk_data);
--
2.17.1
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