[PATCH V3 1/2] mmc: add OpenPiton mmc support

[Tianrui Wei <tianrui-wei@outlook.com>]

This patch adds mmc support for OpenPiton.
Specifically, some dts bindings were not used because
our mmc controller doens't have those configuration
options, it only exposes a dummy mmap interface for
CPU.

Signed-off-by: Tianrui Wei <tianrui-wei@outlook.com>
Signed-off-by: Jonathan Balkind <jbalkind@ucsb.edu>


---

 drivers/mmc/Kconfig                     |   6 +
 drivers/mmc/Makefile                    |   1 +
 drivers/mmc/piton_mmc.c                 | 171 +++++
 3 files changed, 178 insertions(+)
 create mode 100644 drivers/mmc/piton_mmc.c

diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 14d79139..41822c39 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -707,6 +707,12 @@ config MMC_SUNXI_HAS_MODE_SWITCH
 	bool
 	depends on MMC_SUNXI
 
+config MMC_PITON
+	bool "MMC support for openpiton SoC"
+  depends on DM_MMC && BLK
+	help
+    This driver enables sd card support in U-Boot port for openpiton
+
 config GENERIC_ATMEL_MCI
 	bool "Atmel Multimedia Card Interface support"
 	depends on DM_MMC && BLK && ARCH_AT91
diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
index 1c849cba..698dfe05 100644
--- a/drivers/mmc/Makefile
+++ b/drivers/mmc/Makefile
@@ -71,6 +71,7 @@ obj-$(CONFIG_MMC_SDHCI_XENON)		+= xenon_sdhci.o
 obj-$(CONFIG_MMC_SDHCI_ZYNQ)		+= zynq_sdhci.o
 
 obj-$(CONFIG_MMC_SUNXI)			+= sunxi_mmc.o
+obj-$(CONFIG_MMC_PITON)     	+= piton_mmc.o
 obj-$(CONFIG_MMC_UNIPHIER)		+= tmio-common.o uniphier-sd.o
 obj-$(CONFIG_RENESAS_SDHI)		+= tmio-common.o renesas-sdhi.o
 obj-$(CONFIG_MMC_BCM2835)		+= bcm2835_sdhost.o
diff --git a/drivers/mmc/piton_mmc.c b/drivers/mmc/piton_mmc.c
new file mode 100644
index 00000000..b550a762
--- /dev/null
+++ b/drivers/mmc/piton_mmc.c
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2009 SAMSUNG Electronics
+ * Minkyu Kang <mk7.kang@samsung.com>
+ * Jaehoon Chung <jh80.chung@samsung.com>
+ * Portions Copyright 2011-2019 NVIDIA Corporation
+ * Portions Copyright 2021 Tianrui Wei
+ * Tianrui Wei <tianrui-wei@outlook.com>
+ */
+
+#include <asm/gpio.h>
+#include <asm/io.h>
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <linux/bitops.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <log.h>
+#include <div64.h>
+#include <mmc.h>
+
+struct piton_mmc_plat {
+	struct mmc_config cfg;
+	struct mmc mmc;
+};
+
+struct piton_mmc_priv {
+	u64 piton_mmc_base_addr; /* peripheral id */
+};
+
+/*
+ * see mmc_read_blocks to see how it is used.
+ * start block is hidden at cmd->arg
+ * also, initialize the block size at init
+ */
+static int piton_mmc_send_cmd(struct udevice *dev, struct mmc_cmd *cmd,
+												struct mmc_data *data)
+{
+	/* check first if this is a pure command */
+	if (data == NULL) {
+		return 0;
+	}
+
+	u64 byte_cnt = data->blocks * data->blocksize;
+	u64 start_block = cmd->cmdarg;
+	unsigned *buff = (unsigned int *) data->dest;
+
+	struct piton_mmc_priv *priv = dev_get_priv(dev);
+	u64 start_addr = priv->piton_mmc_base_addr + (start_block);
+
+	/* if there is a read */
+	if (data->flags & MMC_DATA_READ) {
+		for (u64 i = 0; i < byte_cnt; i += 4) {
+			*(buff) = readl((void *)(start_addr + i));
+			buff++;
+		}
+	} else {
+		/* else there is a write
+		 * we don't handle write, so error right away
+		 */
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int piton_mmc_ofdata_to_platdata(struct udevice *dev)
+{
+	struct piton_mmc_priv *priv = dev_get_priv(dev);
+	struct piton_mmc_plat *plat = dev_get_platdata(dev);
+	struct mmc_config *cfg;
+	struct mmc *mmc;
+	/* fill in device description */
+	struct blk_desc *bdesc;
+
+	priv->piton_mmc_base_addr = dev_read_addr(dev);
+	cfg = &plat->cfg;
+	cfg->name = "PITON MMC";
+	cfg->host_caps = MMC_MODE_8BIT;
+	cfg->f_max = 100000;
+	cfg->f_min = 400000;
+	cfg->voltages = MMC_VDD_21_22;
+
+	mmc = &plat->mmc;
+	mmc->read_bl_len = MMC_MAX_BLOCK_LEN;
+	mmc->capacity_user = 0x100000000;
+	mmc->capacity_user *= mmc->read_bl_len;
+	mmc->capacity_boot = 0;
+	mmc->capacity_rpmb = 0;
+	for (int i = 0; i < 4; i++)
+		mmc->capacity_gp[i] = 0;
+	mmc->capacity = 0x2000000000ULL;
+	mmc->has_init = 1;
+
+	bdesc = mmc_get_blk_desc(mmc);
+	bdesc->lun = 0;
+	bdesc->hwpart = 0;
+	bdesc->type = 0;
+	bdesc->blksz = mmc->read_bl_len;
+	bdesc->log2blksz = LOG2(bdesc->blksz);
+	bdesc->lba = lldiv(mmc->capacity, mmc->read_bl_len);
+
+	return 0;
+}
+
+
+/* test if piton has the micro mmc card present
+ * always return 1, which means present
+ */
+static int piton_mmc_getcd(struct udevice *dev) {
+	/*
+	 * always return 1
+	 */
+	return 1;
+}
+
+/* dummy function, piton_mmc don't need initialization in hw*/
+static const struct dm_mmc_ops piton_mmc_ops = {
+	.send_cmd = piton_mmc_send_cmd,
+	.set_ios = piton_mmc_set_ios,
+	.get_cd = piton_mmc_getcd,
+};
+
+static int piton_mmc_probe(struct udevice *dev)
+{
+	struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
+	struct piton_mmc_plat *plat = dev_get_platdata(dev);
+	struct mmc_config *cfg = &plat->cfg;
+
+	cfg->name = dev->name;
+	upriv->mmc = &plat->mmc;
+	upriv->mmc->has_init = 1;
+	upriv->mmc->capacity = 0x2000000000ULL;
+	upriv->mmc->read_bl_len = MMC_MAX_BLOCK_LEN;
+
+	return 0;
+}
+
+static int piton_mmc_bind(struct udevice *dev)
+{
+	struct piton_mmc_plat *plat = dev_get_platdata(dev);
+	struct mmc_config *cfg = &plat->cfg;
+
+	cfg->name = dev->name;
+	cfg->host_caps = MMC_MODE_HS_52MHz | MMC_MODE_HS | MMC_MODE_8BIT;
+	cfg->voltages = MMC_VDD_165_195 | MMC_VDD_32_33 | MMC_VDD_33_34;
+	cfg->f_min = 1000000;
+	cfg->f_max = 52000000;
+	cfg->b_max = U32_MAX;
+
+	return mmc_bind(dev, &plat->mmc, cfg);
+}
+
+static const struct udevice_id piton_mmc_ids[] = {
+		{.compatible = "openpiton,piton-mmc"},
+		{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(piton_mmc_drv) = {
+	.name = "piton_mmc",
+	.id = UCLASS_MMC,
+	.of_match = piton_mmc_ids,
+	.ofdata_to_platdata = piton_mmc_ofdata_to_platdata,
+	.bind = piton_mmc_bind,
+	.probe = piton_mmc_probe,
+	.ops = &piton_mmc_ops,
+	.platdata_auto_alloc_size = sizeof(struct piton_mmc_plat),
+	.priv_auto_alloc_size = sizeof(struct piton_mmc_priv),
+};
-- 
2.17.1