[PATCH 17/28] mci: sdhci: atmel: extend driver for PBL usage

From: Ahmad Fatoum <a.fatoum@pengutronix.de>
To: barebox@lists.infradead.org
Cc: Ahmad Fatoum <a.fatoum@pengutronix.de>
Subject: [PATCH 17/28] mci: sdhci: atmel: extend driver for PBL usage
Date: Wed,  1 Jul 2020 11:11:11 +0200	[thread overview]
Message-ID: <20200701091122.3437-18-a.fatoum@pengutronix.de> (raw)
In-Reply-To: <20200701091122.3437-1-a.fatoum@pengutronix.de>

The BootROM resets both the SD/MMC host controller and the pin controller,
but the card itself remains in transfer mode. If we redo host-side
setup, we can directly read new blocks off the card.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 drivers/mci/Kconfig              |   4 +
 drivers/mci/Makefile             |   1 +
 drivers/mci/atmel-sdhci-common.c |   3 +
 drivers/mci/atmel-sdhci-pbl.c    | 128 +++++++++++++++++++++++++++++++
 4 files changed, 136 insertions(+)
 create mode 100644 drivers/mci/atmel-sdhci-pbl.c

diff --git a/drivers/mci/Kconfig b/drivers/mci/Kconfig
index 6ae1e812528c..3026b25cadc9 100644
--- a/drivers/mci/Kconfig
+++ b/drivers/mci/Kconfig
@@ -187,3 +187,7 @@ endif
 config MCI_IMX_ESDHC_PBL
 	bool
 	select MCI_SDHCI
+
+config MCI_ATMEL_SDHCI_PBL
+	bool
+	select MCI_SDHCI
diff --git a/drivers/mci/Makefile b/drivers/mci/Makefile
index 177483dcfba5..4a5363367476 100644
--- a/drivers/mci/Makefile
+++ b/drivers/mci/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_MCI_ATMEL_SDHCI)	+= atmel-sdhci.o atmel-sdhci-common.o
 obj-$(CONFIG_MCI_BCM283X)	+= mci-bcm2835.o
 obj-$(CONFIG_MCI_BCM283X_SDHOST)	+= bcm2835-sdhost.o
 obj-$(CONFIG_MCI_DOVE)		+= dove-sdhci.o
+pbl-$(CONFIG_MCI_ATMEL_SDHCI_PBL)	+= atmel-sdhci-pbl.o atmel-sdhci-common.o
 obj-$(CONFIG_MCI_IMX)		+= imx.o
 obj-$(CONFIG_MCI_IMX_ESDHC)	+= imx-esdhc.o imx-esdhc-common.o
 pbl-$(CONFIG_MCI_IMX_ESDHC_PBL)	+= imx-esdhc-pbl.o imx-esdhc-common.o
diff --git a/drivers/mci/atmel-sdhci-common.c b/drivers/mci/atmel-sdhci-common.c
index 1884f3836337..a83610c3d090 100644
--- a/drivers/mci/atmel-sdhci-common.c
+++ b/drivers/mci/atmel-sdhci-common.c
@@ -12,7 +12,10 @@
 #include <common.h>
 #include <mci.h>
 
+#include <mach/early_udelay.h>
+
 #ifdef __PBL__
+#define udelay early_udelay
 #undef  dev_err
 #define dev_err(d, ...)		pr_err(__VA_ARGS__)
 #undef  dev_warn
diff --git a/drivers/mci/atmel-sdhci-pbl.c b/drivers/mci/atmel-sdhci-pbl.c
new file mode 100644
index 000000000000..626e4008fe85
--- /dev/null
+++ b/drivers/mci/atmel-sdhci-pbl.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: BSD-1-Clause
+/*
+ * Copyright (c) 2015, Atmel Corporation
+ * Copyright (c) 2019, Ahmad Fatoum, Pengutronix
+ *
+ * Atmel's name may not be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ */
+
+#include <common.h>
+#include <pbl.h>
+#include <mci.h>
+#include <debug_ll.h>
+#include <mach/xload.h>
+#include "atmel-sdhci.h"
+
+#include <mach/early_udelay.h>
+
+#ifdef __PBL__
+#define udelay early_udelay
+#endif
+
+#define SECTOR_SIZE			512
+#define SUPPORT_MAX_BLOCKS		16U
+
+struct at91_sdhci_priv {
+	struct at91_sdhci host;
+	bool highcapacity_card;
+};
+
+static int sd_cmd_stop_transmission(struct at91_sdhci_priv *priv)
+{
+	struct mci_cmd cmd = {
+		.cmdidx = MMC_CMD_STOP_TRANSMISSION,
+		.resp_type = MMC_RSP_R1b,
+	};
+
+	return at91_sdhci_send_command(&priv->host, &cmd, NULL);
+}
+
+static int sd_cmd_read_multiple_block(struct at91_sdhci_priv *priv,
+				      void *buf,
+				      unsigned int start,
+				      unsigned int block_count)
+{
+	u16 block_len = SECTOR_SIZE;
+	struct mci_data data;
+	struct mci_cmd cmd = {
+		.cmdidx = MMC_CMD_READ_MULTIPLE_BLOCK,
+		.resp_type = MMC_RSP_R1,
+		.cmdarg = start,
+	};
+
+	if (!priv->highcapacity_card)
+		cmd.cmdarg *= block_len;
+
+	data.dest = buf;
+	data.flags = MMC_DATA_READ;
+	data.blocksize = block_len;
+	data.blocks = block_count;
+
+	return at91_sdhci_send_command(&priv->host, &cmd, &data);
+}
+
+static int at91_sdhci_bio_read(struct pbl_bio *bio, off_t start,
+				void *buf, unsigned int nblocks)
+{
+	struct at91_sdhci_priv *priv = bio->priv;
+	unsigned int blocks_done = 0;
+	unsigned int blocks;
+	unsigned int block_len = SECTOR_SIZE;
+	unsigned int blocks_read;
+	int ret;
+
+	/*
+	 * Refer to the at91sam9g20 datasheet:
+	 * Figure 35-10. Read Function Flow Diagram
+	*/
+
+	while (blocks_done < nblocks) {
+		blocks = min(nblocks - blocks_done, SUPPORT_MAX_BLOCKS);
+
+		blocks_read = sd_cmd_read_multiple_block(priv, buf,
+							 start + blocks_done,
+							 blocks);
+
+		ret = sd_cmd_stop_transmission(priv);
+		if (ret)
+			return ret;
+
+		blocks_done += blocks_read;
+
+		if (blocks_read != blocks)
+			break;
+
+		buf += blocks * block_len;
+	}
+
+	return blocks_done;
+}
+
+static struct at91_sdhci_priv atmel_sdcard;
+
+int at91_sdhci_bio_init(struct pbl_bio *bio, void __iomem *base)
+{
+	struct at91_sdhci_priv *priv = &atmel_sdcard;
+	struct at91_sdhci *host = &priv->host;
+	struct mci_ios ios = { .bus_width = MMC_BUS_WIDTH_1, .clock = 25000000 };
+	int ret;
+
+	bio->priv = priv;
+	bio->read = at91_sdhci_bio_read;
+
+	at91_sdhci_mmio_init(host, base);
+
+	sdhci_reset(&host->sdhci, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
+
+	ret = at91_sdhci_init(host, 240000000, true, true);
+	if (ret)
+		return ret;
+
+	ret = at91_sdhci_set_ios(host, &ios);
+
+	 // FIXME can we determine this without leaving SD transfer mode?
+	priv->highcapacity_card = 1;
+
+	return 0;
+}
-- 
2.27.0


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