mmc: sdhci-pltfm: add -pltfm driver for imx35/51

This driver adds basic support for the esdhc-core found on e.g.
imx35/51, as a platform driver.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Anton Vorontsov <cbouatmailru@gmail.com>
Tested-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 143 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
new file mode 100644
index 000000000000..2e9cca19c90b
--- /dev/null
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -0,0 +1,143 @@
+/*
+ * Freescale eSDHC i.MX controller driver for the platform bus.
+ *
+ * derived from the OF-version.
+ *
+ * Copyright (c) 2010 Pengutronix e.K.
+ *   Author: Wolfram Sang <w.sang@pengutronix.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ */
+
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/sdhci-pltfm.h>
+#include "sdhci.h"
+#include "sdhci-pltfm.h"
+#include "sdhci-esdhc.h"
+
+static inline void esdhc_clrset_le(struct sdhci_host *host, u32 mask, u32 val, int reg)
+{
+	void __iomem *base = host->ioaddr + (reg & ~0x3);
+	u32 shift = (reg & 0x3) * 8;
+
+	writel(((readl(base) & ~(mask << shift)) | (val << shift)), base);
+}
+
+static u16 esdhc_readw_le(struct sdhci_host *host, int reg)
+{
+	if (unlikely(reg == SDHCI_HOST_VERSION))
+		reg ^= 2;
+
+	return readw(host->ioaddr + reg);
+}
+
+static void esdhc_writew_le(struct sdhci_host *host, u16 val, int reg)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+	switch (reg) {
+	case SDHCI_TRANSFER_MODE:
+		/*
+		 * Postpone this write, we must do it together with a
+		 * command write that is down below.
+		 */
+		pltfm_host->scratchpad = val;
+		return;
+	case SDHCI_COMMAND:
+		writel(val << 16 | pltfm_host->scratchpad,
+			host->ioaddr + SDHCI_TRANSFER_MODE);
+		return;
+	case SDHCI_BLOCK_SIZE:
+		val &= ~SDHCI_MAKE_BLKSZ(0x7, 0);
+		break;
+	}
+	esdhc_clrset_le(host, 0xffff, val, reg);
+}
+
+static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg)
+{
+	u32 new_val;
+
+	switch (reg) {
+	case SDHCI_POWER_CONTROL:
+		/*
+		 * FSL put some DMA bits here
+		 * If your board has a regulator, code should be here
+		 */
+		return;
+	case SDHCI_HOST_CONTROL:
+		/* FSL messed up here, so we can just keep those two */
+		new_val = val & (SDHCI_CTRL_LED | SDHCI_CTRL_4BITBUS);
+		/* ensure the endianess */
+		new_val |= ESDHC_HOST_CONTROL_LE;
+		/* DMA mode bits are shifted */
+		new_val |= (val & SDHCI_CTRL_DMA_MASK) << 5;
+
+		esdhc_clrset_le(host, 0xffff, new_val, reg);
+		return;
+	}
+	esdhc_clrset_le(host, 0xff, val, reg);
+}
+
+static unsigned int esdhc_pltfm_get_max_clock(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+	return clk_get_rate(pltfm_host->clk);
+}
+
+static unsigned int esdhc_pltfm_get_min_clock(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+	return clk_get_rate(pltfm_host->clk) / 256 / 16;
+}
+
+static int esdhc_pltfm_init(struct sdhci_host *host, struct sdhci_pltfm_data *pdata)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct clk *clk;
+
+	clk = clk_get(mmc_dev(host->mmc), NULL);
+	if (IS_ERR(clk)) {
+		dev_err(mmc_dev(host->mmc), "clk err\n");
+		return PTR_ERR(clk);
+	}
+	clk_enable(clk);
+	pltfm_host->clk = clk;
+
+	return 0;
+}
+
+static void esdhc_pltfm_exit(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+	clk_disable(pltfm_host->clk);
+	clk_put(pltfm_host->clk);
+}
+
+static struct sdhci_ops sdhci_esdhc_ops = {
+	.read_w = esdhc_readw_le,
+	.write_w = esdhc_writew_le,
+	.write_b = esdhc_writeb_le,
+	.set_clock = esdhc_set_clock,
+	.get_max_clock = esdhc_pltfm_get_max_clock,
+	.get_min_clock = esdhc_pltfm_get_min_clock,
+};
+
+struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
+	.quirks = ESDHC_DEFAULT_QUIRKS | SDHCI_QUIRK_NO_MULTIBLOCK
+			| SDHCI_QUIRK_BROKEN_ADMA,
+	/* ADMA has issues. Might be fixable */
+	/* NO_MULTIBLOCK might be MX35 only (Errata: ENGcm07207) */
+	.ops = &sdhci_esdhc_ops,
+	.init = esdhc_pltfm_init,
+	.exit = esdhc_pltfm_exit,
+};