Hi Peter
On 05/22/2014 05:18 PM, Peter Griffin wrote:
This platform driver adds initial support for the SDHCI host controller
found on STMicroelectronics SoCs.
It has been tested on STiH41x b2020 platforms currently.
Signed-off-by: Peter Griffin <peter.griffin@xxxxxxxxxx>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
---
drivers/mmc/host/Kconfig | 12 +++
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/sdhci-st.c | 244 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 257 insertions(+)
create mode 100644 drivers/mmc/host/sdhci-st.c
[...]
diff --git a/drivers/mmc/host/sdhci-st.c b/drivers/mmc/host/sdhci-st.c
new file mode 100644
index 0000000..1790fa7
--- /dev/null
+++ b/drivers/mmc/host/sdhci-st.c
@@ -0,0 +1,244 @@
+/*
+ * Support for SDHCI on STMicroelectronics SoCs
+ *
+ * Copyright (C) 2014 STMicroelectronics Ltd
+ * Author: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
+ *
+ * Based on sdhci-cns3xxx.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/of_gpio.h>
+#include <linux/mmc/host.h>
+#include <linux/reset.h>
+
+#include "sdhci-pltfm.h"
+
+struct st_mmc_platform_data {
+ struct reset_control *rstc;
+};
Since it uses the generic reset framework, could we imagine moving the
reset to the sdhci_pltfm_host struct?
Doing this, we could get rid of st_mmc_platform_data.
+
+static int sdhci_st_8bit_width(struct sdhci_host *host, int width)
+{
+ u8 ctrl;
+
+ ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
+
+ switch (width) {
+ case MMC_BUS_WIDTH_8:
+ ctrl |= SDHCI_CTRL_8BITBUS;
+ ctrl &= ~SDHCI_CTRL_4BITBUS;
+ break;
+ case MMC_BUS_WIDTH_4:
+ ctrl |= SDHCI_CTRL_4BITBUS;
+ ctrl &= ~SDHCI_CTRL_8BITBUS;
+ break;
+ default:
+ ctrl &= ~(SDHCI_CTRL_8BITBUS | SDHCI_CTRL_4BITBUS);
+ break;
You can remove the break here.
+ }
+
+ sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+
+ return 0;
+}
+
+static unsigned int sdhci_st_get_max_clk(struct sdhci_host *host)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+ return clk_get_rate(pltfm_host->clk);
+}
+
+static u32 sdhci_st_readl(struct sdhci_host *host, int reg)
+{
+ u32 ret;
+
+ switch (reg) {
+ case SDHCI_CAPABILITIES:
+ ret = readl(host->ioaddr + reg);
+ /* Support 3.3V and 1.8V */
+ ret &= ~SDHCI_CAN_VDD_300;
+ break;
+ default:
+ ret = readl(host->ioaddr + reg);
Could we use readl_relaxed?
+ }
+ return ret;
+}
+
+static const struct sdhci_ops sdhci_st_ops = {
+ .get_max_clock = sdhci_st_get_max_clk,
+ .platform_bus_width = sdhci_st_8bit_width,
+ .read_l = sdhci_st_readl,
+};
+
+static const struct sdhci_pltfm_data sdhci_st_pdata = {
+ .ops = &sdhci_st_ops,
+ .quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC |
+ SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
+};
+
+
+static int sdhci_st_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct sdhci_host *host;
+ struct st_mmc_platform_data *pdata;
+ struct sdhci_pltfm_host *pltfm_host;
+ struct clk *clk;
+ int ret = 0;
+ u16 host_version;
+
+ dev_dbg(&pdev->dev, "SDHCI ST platform driver\n");
You can remove this I think.
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ pdata->rstc = devm_reset_control_get(&pdev->dev, NULL);
+ if (IS_ERR(pdata->rstc))
+ pdata->rstc = NULL;
+ else
+ reset_control_deassert(pdata->rstc);
+
+ clk = devm_clk_get(&pdev->dev, "mmc");
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "Perpheral clk not found\n");
+ return PTR_ERR(clk);
+ }
+
+ host = sdhci_pltfm_init(pdev, &sdhci_st_pdata, 0);
+ if (IS_ERR(host)) {
+ dev_err(&pdev->dev, "Failed sdhci_pltfm_init\n");
+ return PTR_ERR(host);
+ }
+
+ clk_prepare_enable(clk);
+
+ host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_BUS_WIDTH_TEST
+ | MMC_CAP_1_8V_DDR;
+
+ if (of_property_read_bool(np, "non-removable"))
+ host->mmc->caps |= MMC_CAP_NONREMOVABLE;
+
+ pltfm_host = sdhci_priv(host);
+ pltfm_host->clk = clk;
+
+ ret = sdhci_add_host(host);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed sdhci_add_host\n");
+ goto err_out;
+ }
+
+ pltfm_host->priv = pdata;
+
+ platform_set_drvdata(pdev, host);
+
+ host_version = readw_relaxed((host->ioaddr + SDHCI_HOST_VERSION));
+
+ dev_dbg(&pdev->dev, "SDHCI ST Initialised: Host Version: 0x%x Vendor Version 0x%x\n",
+ host_version, ((host_version & SDHCI_VENDOR_VER_MASK) >>
+ SDHCI_VENDOR_VER_SHIFT));
Maybe you could change to dev_info here. It might be interresting to
always have IP version.
+
+ return 0;
+
+err_out:
+ clk_disable_unprepare(clk);
+ sdhci_pltfm_free(pdev);
+
+ return ret;
+}
[...]
Regards,
Maxime
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