[PATCH 3/4] mmc: cavium: Add MMC support for Octeon SOCs.

["Steven J. Hill" <steven.hill@cavium.com>]

From: "Steven J. Hill" <Steven.Hill@cavium.com>

Add platform driver for Octeon SOCs.

Signed-off-by: Steven J. Hill <Steven.Hill@cavium.com>
Signed-off-by: David Daney <david.daney@cavium.com>
---
 drivers/mmc/host/Kconfig         |  10 ++
 drivers/mmc/host/Makefile        |   2 +
 drivers/mmc/host/cavium-octeon.c | 351 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 363 insertions(+)
 create mode 100644 drivers/mmc/host/cavium-octeon.c

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index c882795..8b9b454 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -622,6 +622,16 @@ config SDH_BFIN_MISSING_CMD_PULLUP_WORKAROUND
 	help
 	  If you say yes here SD-Cards may work on the EZkit.
 
+config MMC_CAVIUM_OCTEON
+	tristate "Cavium OCTEON SD/MMC Card Interface support"
+	depends on CAVIUM_OCTEON_SOC
+	help
+	  This selects Cavium OCTEON SD/MMC card Interface.
+	  If you have an OCTEON board with a Multimedia Card slot,
+	  say Y or M here.
+
+	  If unsure, say N.
+
 config MMC_CAVIUM_THUNDERX
 	tristate "Cavium ThunderX SD/MMC Card Interface support"
 	depends on PCI && 64BIT && (ARM64 || COMPILE_TEST)
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index f40c6b3..7f1ee0b 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -42,6 +42,8 @@ obj-$(CONFIG_MMC_SDHI)		+= sh_mobile_sdhi.o
 obj-$(CONFIG_MMC_CB710)		+= cb710-mmc.o
 obj-$(CONFIG_MMC_VIA_SDMMC)	+= via-sdmmc.o
 obj-$(CONFIG_SDH_BFIN)		+= bfin_sdh.o
+octeon-mmc-objs := cavium.o cavium-octeon.o
+obj-$(CONFIG_MMC_CAVIUM_OCTEON) += octeon-mmc.o
 thunderx-mmc-objs := cavium.o cavium-thunderx.o
 obj-$(CONFIG_MMC_CAVIUM_THUNDERX) += thunderx-mmc.o
 obj-$(CONFIG_MMC_DW)		+= dw_mmc.o
diff --git a/drivers/mmc/host/cavium-octeon.c b/drivers/mmc/host/cavium-octeon.c
new file mode 100644
index 0000000..772d090
--- /dev/null
+++ b/drivers/mmc/host/cavium-octeon.c
@@ -0,0 +1,351 @@
+/*
+ * Driver for MMC and SSD cards for Cavium OCTEON SOCs.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2012-2017 Cavium Inc.
+ */
+#include <linux/dma-mapping.h>
+#include <linux/gpio/consumer.h>
+#include <linux/interrupt.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/slot-gpio.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <asm/octeon/octeon.h>
+#include "cavium.h"
+
+#define CVMX_MIO_BOOT_CTL CVMX_ADD_IO_SEG(0x00011800000000D0ull)
+
+/*
+ * The l2c* functions below are used for the EMMC-17978 workaround.
+ *
+ * Due to a bug in the design of the MMC bus hardware, the 2nd to last
+ * cache block of a DMA read must be locked into the L2 Cache.
+ * Otherwise, data corruption may occur.
+ */
+static inline void *phys_to_ptr(u64 address)
+{
+	return (void *)(address | (1ull << 63)); /* XKPHYS */
+}
+
+/*
+ * Lock a single line into L2. The line is zeroed before locking
+ * to make sure no dram accesses are made.
+ */
+static void l2c_lock_line(u64 addr)
+{
+	char *addr_ptr = phys_to_ptr(addr);
+
+	asm volatile (
+		"cache 31, %[line]"	/* Unlock the line */
+		::[line] "m" (*addr_ptr));
+}
+
+/* Unlock a single line in the L2 cache. */
+static void l2c_unlock_line(u64 addr)
+{
+	char *addr_ptr = phys_to_ptr(addr);
+
+	asm volatile (
+		"cache 23, %[line]"	/* Unlock the line */
+		::[line] "m" (*addr_ptr));
+}
+
+/* Locks a memory region in the L2 cache. */
+static void l2c_lock_mem_region(u64 start, u64 len)
+{
+	u64 end;
+
+	/* Round start/end to cache line boundaries */
+	end = ALIGN(start + len - 1, CVMX_CACHE_LINE_SIZE);
+	start = ALIGN(start, CVMX_CACHE_LINE_SIZE);
+
+	while (start <= end) {
+		l2c_lock_line(start);
+		start += CVMX_CACHE_LINE_SIZE;
+	}
+	asm volatile("sync");
+}
+
+/* Unlock a memory region in the L2 cache. */
+static void l2c_unlock_mem_region(u64 start, u64 len)
+{
+	u64 end;
+
+	/* Round start/end to cache line boundaries */
+	end = ALIGN(start + len - 1, CVMX_CACHE_LINE_SIZE);
+	start = ALIGN(start, CVMX_CACHE_LINE_SIZE);
+
+	while (start <= end) {
+		l2c_unlock_line(start);
+		start += CVMX_CACHE_LINE_SIZE;
+	}
+}
+
+static void octeon_mmc_acquire_bus(struct cvm_mmc_host *host)
+{
+	if (!host->has_ciu3) {
+		down(&octeon_bootbus_sem);
+		/* For CN70XX, switch the MMC controller onto the bus. */
+		if (OCTEON_IS_MODEL(OCTEON_CN70XX))
+			writeq(0, (void __iomem *)CVMX_MIO_BOOT_CTL);
+	} else {
+		down(&host->mmc_serializer);
+	}
+}
+
+static void octeon_mmc_release_bus(struct cvm_mmc_host *host)
+{
+	if (!host->has_ciu3)
+		up(&octeon_bootbus_sem);
+	else
+		up(&host->mmc_serializer);
+}
+
+static void octeon_mmc_int_enable(struct cvm_mmc_host *host, u64 val)
+{
+	writeq(val, host->base + MIO_EMM_INT(host));
+	if (!host->dma_active || (host->dma_active && !host->has_ciu3))
+		writeq(val, host->base + MIO_EMM_INT_EN(host));
+}
+
+static void octeon_mmc_set_shared_power(struct cvm_mmc_host *host, int dir)
+{
+	if (dir == 0)
+		if (!atomic_dec_return(&host->shared_power_users))
+			gpiod_set_value_cansleep(host->global_pwr_gpiod, 0);
+	if (dir == 1)
+		if (atomic_inc_return(&host->shared_power_users) == 1)
+			gpiod_set_value_cansleep(host->global_pwr_gpiod, 1);
+}
+
+static void octeon_mmc_dmar_fixup(struct cvm_mmc_host *host,
+				  struct mmc_command *cmd,
+				  struct mmc_data *data,
+				  u64 addr)
+{
+	if (cmd->opcode != MMC_WRITE_MULTIPLE_BLOCK)
+		return;
+	if (data->blksz * data->blocks <= 1024)
+		return;
+
+	host->n_minus_one = addr + (data->blksz * data->blocks) - 1024;
+	l2c_lock_mem_region(host->n_minus_one, 512);
+}
+
+static void octeon_mmc_dmar_fixup_done(struct cvm_mmc_host *host)
+{
+	if (!host->n_minus_one)
+		return;
+	l2c_unlock_mem_region(host->n_minus_one, 512);
+	host->n_minus_one = 0;
+}
+
+static int octeon_mmc_probe(struct platform_device *pdev)
+{
+	struct device_node *cn, *node = pdev->dev.of_node;
+	struct cvm_mmc_host *host;
+	struct resource	*res;
+	void __iomem *base;
+	int mmc_irq[9];
+	int i, ret = 0;
+	u64 val;
+
+	host = devm_kzalloc(&pdev->dev, sizeof(*host), GFP_KERNEL);
+	if (!host)
+		return -ENOMEM;
+
+	spin_lock_init(&host->irq_handler_lock);
+	sema_init(&host->mmc_serializer, 1);
+
+	host->dev = &pdev->dev;
+	host->acquire_bus = octeon_mmc_acquire_bus;
+	host->release_bus = octeon_mmc_release_bus;
+	host->int_enable = octeon_mmc_int_enable;
+	host->set_shared_power = octeon_mmc_set_shared_power;
+	if (OCTEON_IS_MODEL(OCTEON_CN6XXX) ||
+	    OCTEON_IS_MODEL(OCTEON_CNF7XXX)) {
+		host->dmar_fixup = octeon_mmc_dmar_fixup;
+		host->dmar_fixup_done = octeon_mmc_dmar_fixup_done;
+	}
+
+	host->sys_freq = octeon_get_io_clock_rate();
+
+	if (of_device_is_compatible(node, "cavium,octeon-7890-mmc")) {
+		host->big_dma_addr = true;
+		host->need_irq_handler_lock = true;
+		host->has_ciu3 = true;
+		host->use_sg = true;
+		/*
+		 * First seven are the EMM_INT bits 0..6, then two for
+		 * the EMM_DMA_INT bits
+		 */
+		for (i = 0; i < 9; i++) {
+			mmc_irq[i] = platform_get_irq(pdev, i);
+			if (mmc_irq[i] < 0)
+				return mmc_irq[i];
+
+			/* work around legacy u-boot device trees */
+			irq_set_irq_type(mmc_irq[i], IRQ_TYPE_EDGE_RISING);
+		}
+	} else {
+		host->big_dma_addr = false;
+		host->need_irq_handler_lock = false;
+		host->has_ciu3 = false;
+		/* First one is EMM second DMA */
+		for (i = 0; i < 2; i++) {
+			mmc_irq[i] = platform_get_irq(pdev, i);
+			if (mmc_irq[i] < 0)
+				return mmc_irq[i];
+		}
+	}
+
+	host->last_slot = -1;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "Platform resource[0] is missing\n");
+		return -ENXIO;
+	}
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+	host->base = (void __iomem *)base;
+	host->reg_off = 0;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res) {
+		dev_err(&pdev->dev, "Platform resource[1] is missing\n");
+		return -EINVAL;
+	}
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+	host->dma_base = (void __iomem *)base;
+	/*
+	 * To keep the register addresses shared we intentionaly use
+	 * a negative offset here, first register used on Octeon therefore
+	 * starts at 0x20 (MIO_EMM_DMA_CFG).
+	 */
+	host->reg_off_dma = -0x20;
+
+	ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(64));
+	if (ret)
+		return ret;
+
+	/*
+	 * Clear out any pending interrupts that may be left over from
+	 * bootloader.
+	 */
+	val = readq(host->base + MIO_EMM_INT(host));
+	writeq(val, host->base + MIO_EMM_INT(host));
+
+	if (host->has_ciu3) {
+		/* Only CMD_DONE, DMA_DONE, CMD_ERR, DMA_ERR */
+		for (i = 1; i <= 4; i++) {
+			ret = devm_request_irq(&pdev->dev, mmc_irq[i],
+					       cvm_mmc_interrupt,
+					       0, cvm_mmc_irq_names[i], host);
+			if (ret < 0) {
+				dev_err(&pdev->dev, "Error: devm_request_irq %d\n",
+					mmc_irq[i]);
+				return ret;
+			}
+		}
+	} else {
+		ret = devm_request_irq(&pdev->dev, mmc_irq[0],
+				       cvm_mmc_interrupt, 0, KBUILD_MODNAME,
+				       host);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "Error: devm_request_irq %d\n",
+				mmc_irq[0]);
+			return ret;
+		}
+	}
+
+	host->global_pwr_gpiod = devm_gpiod_get_optional(&pdev->dev,
+							 "power-gpios",
+							 GPIOD_OUT_HIGH);
+	if (IS_ERR(host->global_pwr_gpiod)) {
+		dev_err(&pdev->dev, "Invalid power GPIO\n");
+		return PTR_ERR(host->global_pwr_gpiod);
+	}
+
+	platform_set_drvdata(pdev, host);
+
+	i = 0;
+	for_each_child_of_node(node, cn) {
+		host->slot_pdev[i] =
+			of_platform_device_create(cn, NULL, &pdev->dev);
+		if (!host->slot_pdev[i]) {
+			i++;
+			continue;
+		}
+		ret = cvm_mmc_of_slot_probe(&host->slot_pdev[i]->dev, host);
+		if (ret) {
+			dev_err(&pdev->dev, "Error populating slots\n");
+			octeon_mmc_set_shared_power(host, 0);
+			return ret;
+		}
+		i++;
+	}
+	return 0;
+}
+
+static int octeon_mmc_remove(struct platform_device *pdev)
+{
+	struct cvm_mmc_host *host = platform_get_drvdata(pdev);
+	u64 dma_cfg;
+	int i;
+
+	for (i = 0; i < CAVIUM_MAX_MMC; i++)
+		if (host->slot[i])
+			cvm_mmc_of_slot_remove(host->slot[i]);
+
+	dma_cfg = readq(host->dma_base + MIO_EMM_DMA_CFG(host));
+	dma_cfg &= ~MIO_EMM_DMA_CFG_EN;
+	writeq(dma_cfg, host->dma_base + MIO_EMM_DMA_CFG(host));
+
+	octeon_mmc_set_shared_power(host, 0);
+	return 0;
+}
+
+static const struct of_device_id octeon_mmc_match[] = {
+	{
+		.compatible = "cavium,octeon-6130-mmc",
+	},
+	{
+		.compatible = "cavium,octeon-7890-mmc",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, octeon_mmc_match);
+
+static struct platform_driver octeon_mmc_driver = {
+	.probe		= octeon_mmc_probe,
+	.remove		= octeon_mmc_remove,
+	.driver		= {
+		.name	= KBUILD_MODNAME,
+		.of_match_table = octeon_mmc_match,
+	},
+};
+
+static int __init octeon_mmc_init(void)
+{
+	return platform_driver_register(&octeon_mmc_driver);
+}
+
+static void __exit octeon_mmc_cleanup(void)
+{
+	platform_driver_unregister(&octeon_mmc_driver);
+}
+
+module_init(octeon_mmc_init);
+module_exit(octeon_mmc_cleanup);
+
+MODULE_AUTHOR("Cavium Inc. <support@cavium.com>");
+MODULE_DESCRIPTION("Low-level driver for Cavium OCTEON MMC/SSD card");
+MODULE_LICENSE("GPL");
-- 
2.1.4