[PATCH v6] mmc: sdhci-moxart: Add MOXA ART SDHCI driver

From: Jonas Jensen
Date: Fri Jan 17 2014 - 04:44:06 EST

Add SDHCI driver for MOXA ART SoCs.

Signed-off-by: Jonas Jensen <jonas.jensen@xxxxxxxxx>
---

Notes:
Changes in v6 fixes a kernel panic in moxart_dma_complete().

Panic only happens with CONFIG_SLAB or CONFIG_SLOB, the same code
works for CONFIG_SLUB, and happens because a cookie belonging
to the channel is passed to dmaengine_tx_status(), e.g.
"host->tx_desc->chan->cookie".

Panic log:
[ 4.130000] mmc0: new SD card at address e624
[ 4.170000] nf_conntrack version 0.5.0 (357 buckets, 1428 max)
[ 4.190000] ip_tables: (C) 2000-2006 Netfilter Core Team
[ 4.190000] TCP: cubic registered
[ 4.200000] NET: Registered protocol family 10
[ 4.240000] sit: IPv6 over IPv4 tunneling driver
[ 4.270000] mmcblk0: mmc0:e624 SD02G 1.84 GiB
[ 4.320000] mmcblk0: p1
[ 4.370000] NET: Registered protocol family 17
[ 4.440000] console [netcon0] enabled
[ 4.440000] netconsole: network logging started
[ 4.450000] moxart-rtc rtc.0: setting system clock to 2014-01-16 13:39:54 UTC (1389879594)
[ 4.550000] kjournald starting. Commit interval 5 seconds
[ 4.550000] EXT3-fs (mmcblk0p1): warning: maximal mount count reached, running e2fsck is recommended
[ 4.570000] EXT3-fs (mmcblk0p1): using internal journal
[ 4.580000] EXT3-fs (mmcblk0p1): mounted filesystem with ordered data mode
[ 4.590000] VFS: Mounted root (ext3 filesystem) on device 179:1.
[ 4.610000] devtmpfs: mounted
[ 4.630000] Freeing unused kernel memory: 156K (c0339000 - c0360000)
[ 4.640000] Unable to handle kernel paging request at virtual address aaaaaaaa
[ 4.640000] pgd = c0004000
[ 4.640000] [aaaaaaaa] *pgd=00000000
[ 4.640000] Internal error: Oops: 1 [#1] ARM
[ 4.640000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.13.0-rc8-next-20140115+ #1577
[ 4.640000] task: c03676a8 ti: c0362000 task.ti: c0362000
[ 4.640000] PC is at moxart_dma_complete+0x14/0x68
[ 4.640000] LR is at vchan_complete+0xcc/0xf4
[ 4.640000] pc : [<c01a6724>] lr : [<c0154a28>] psr: a0000013
[ 4.640000] sp : c0363e98 ip : c037ffcc fp : c0380f00
[ 4.640000] r10: c1a867e0 r9 : c0380f38 r8 : c0363eb0
[ 4.640000] r7 : 00100100 r6 : 00200200 r5 : c01a6710 r4 : c1a867e0
[ 4.640000] r3 : c1ac0030 r2 : c0363e9c r1 : c03676a8 r0 : aaaaaaaa
[ 4.640000] Flags: NzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
[ 4.640000] Control: 0000397f Table: 00004000 DAC: 00000017
[ 4.640000] Process swapper (pid: 0, stack limit = 0xc03621c0)
[ 4.640000] Stack: (0xc0363e98 to 0xc0364000)
[ 4.640000] 3e80: c1a867e0 c03676a8
[ 4.640000] 3ea0: 00000000 c03676a8 c1871158 c0154a28 c0363eb0 c0363eb0 60000013 c1871184
[ 4.640000] 3ec0: c03694d4 00000000 00000000 00000006 00000100 c0018fc4 c036bc60 00000007
[ 4.640000] 3ee0: 00000040 c0362000 c0380f20 c0018950 c185b894 c185b894 c185b840 00000006
[ 4.640000] 3f00: 0000000a 00200000 00000001 ffff8ca1 00000000 00000011 00000000 c0934d40
[ 4.640000] 3f20: 00000001 c0363f68 66015261 c0352624 00000000 c0018d38 00000011 c0009a14
[ 4.640000] 3f40: c18020e4 01000000 00000018 c0008538 c0009b94 20000013 ffffffff c0363f9c
[ 4.640000] 3f60: c0998200 c000bfb8 00000001 c03676a8 00000000 20000013 c0362000 c0364020
[ 4.640000] 3f80: c0364110 ffffffff c0998200 66015261 c0352624 00000000 f6aa4ecf c0363fb0
[ 4.640000] 3fa0: c003da20 c0009b94 20000013 ffffffff c03676a8 c0047548 c03676a8 c0339988
[ 4.640000] 3fc0: ffffffff ffffffff c03394d4 00000000 00000000 c0352624 00000000 0000397d
[ 4.640000] 3fe0: c03640a4 c0352620 c03689ec 00004000 003517b4 00008040 00000000 00000000
[ 4.640000] [<c01a6724>] (moxart_dma_complete) from [<c0154a28>] (vchan_complete+0xcc/0xf4)
[ 4.640000] [<c0154a28>] (vchan_complete) from [<c0018fc4>] (tasklet_action+0x84/0xd4)
[ 4.640000] [<c0018fc4>] (tasklet_action) from [<c0018950>] (__do_softirq+0x170/0x2a4)
[ 4.640000] [<c0018950>] (__do_softirq) from [<c0018d38>] (irq_exit+0x80/0x100)
[ 4.640000] [<c0018d38>] (irq_exit) from [<c0009a14>] (handle_IRQ+0x60/0x80)
[ 4.640000] [<c0009a14>] (handle_IRQ) from [<c0008538>] (handle_irq+0x88/0x9c)
[ 4.640000] [<c0008538>] (handle_irq) from [<c000bfb8>] (__irq_svc+0x38/0x48)
[ 4.640000] Exception stack(0xc0363f68 to 0xc0363fb0)
[ 4.640000] 3f60: 00000001 c03676a8 00000000 20000013 c0362000 c0364020
[ 4.640000] 3f80: c0364110 ffffffff c0998200 66015261 c0352624 00000000 f6aa4ecf c0363fb0
[ 4.640000] 3fa0: c003da20 c0009b94 20000013 ffffffff
[ 4.640000] [<c000bfb8>] (__irq_svc) from [<c0009b94>] (arch_cpu_idle+0x3c/0x48)
[ 4.640000] [<c0009b94>] (arch_cpu_idle) from [<c0047548>] (cpu_startup_entry+0x80/0xf0)
[ 4.640000] [<c0047548>] (cpu_startup_entry) from [<c0339988>] (start_kernel+0x298/0x2e0)
[ 4.640000] Code: e5903030 e1a04000 e593000c e28d2004 (e5903000)
[ 4.950000] ---[ end trace e911ec2d43c1d3c3 ]---
[ 4.960000] Kernel panic - not syncing: Fatal exception in interrupt

Changes since v5:

1. add local dma_cookie_t to host struct
2. store dmaengine_submit() return value to [1]
3. use [1] when calling dmaengine_tx_status()

Applies to next-20140117

.../devicetree/bindings/mmc/moxa,moxart-sdhci.txt | 28 +
drivers/mmc/host/Kconfig | 9 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/sdhci-moxart.c | 931 +++++++++++++++++++++
4 files changed, 969 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mmc/moxa,moxart-sdhci.txt
create mode 100644 drivers/mmc/host/sdhci-moxart.c

diff --git a/Documentation/devicetree/bindings/mmc/moxa,moxart-sdhci.txt b/Documentation/devicetree/bindings/mmc/moxa,moxart-sdhci.txt
new file mode 100644
index 0000000..020b13e
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/moxa,moxart-sdhci.txt
@@ -0,0 +1,28 @@
+MOXA ART SD Host Controller Interface
+
+Required properties:
+
+- compatible : Must be "moxa,moxart-sdhci"
+- reg : Should contain registers location and length
+- interrupts : Should contain the interrupt number
+- clocks : Should contain phandle for the clock feeding the SDHCI controller
+
+Optional properties:
+
+These are optional but required to enable DMA transfer mode:
+
+- dmas : Should contain two DMA channels, line request number must be 5 for
+ both channels
+- dma-names : Must be "tx", "rx"
+
+Example:
+
+ sdhci: sdhci@98e00000 {
+ compatible = "moxa,moxart-sdhci";
+ reg = <0x98e00000 0x5C>;
+ interrupts = <5 0>;
+ clocks = <&coreclk>;
+ dmas = <&dma 0 5>,
+ <&dma 1 5>;
+ dma-names = "tx", "rx";
+ };
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 1384f67..e972190 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -283,6 +283,15 @@ config MMC_SDHCI_BCM2835

If unsure, say N.

+config MMC_SDHCI_MOXART
+ tristate "MOXART SD Host Controller Interface support"
+ depends on ARCH_MOXART && MMC
+ help
+ This selects the MOXART SD Host Controller Interface.
+ MOXA provides one multi-functional card reader which can
+ be found on some embedded hardware such as UC-7112-LX.
+ If you have a controller with this interface, say Y here.
+
config MMC_OMAP
tristate "TI OMAP Multimedia Card Interface support"
depends on ARCH_OMAP
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 3483b6b..39e2554 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -64,6 +64,7 @@ obj-$(CONFIG_MMC_SDHCI_OF_ESDHC) += sdhci-of-esdhc.o
obj-$(CONFIG_MMC_SDHCI_OF_HLWD) += sdhci-of-hlwd.o
obj-$(CONFIG_MMC_SDHCI_BCM_KONA) += sdhci-bcm-kona.o
obj-$(CONFIG_MMC_SDHCI_BCM2835) += sdhci-bcm2835.o
+obj-$(CONFIG_MMC_SDHCI_MOXART) += sdhci-moxart.o

ifeq ($(CONFIG_CB710_DEBUG),y)
CFLAGS-cb710-mmc += -DDEBUG
diff --git a/drivers/mmc/host/sdhci-moxart.c b/drivers/mmc/host/sdhci-moxart.c
new file mode 100644
index 0000000..f0bf3e0
--- /dev/null
+++ b/drivers/mmc/host/sdhci-moxart.c
@@ -0,0 +1,931 @@
+/*
+ * MOXA ART MMC host driver.
+ *
+ * Copyright (C) 2013 Jonas Jensen
+ *
+ * Jonas Jensen <jonas.jensen@xxxxxxxxx>
+ *
+ * Based on code from
+ * Moxa Technologies Co., Ltd. <www.moxa.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/blkdev.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/sd.h>
+#include <linux/mmc/mmc.h>
+#include <linux/sched.h>
+#include <linux/io.h>
+#include <linux/gpio.h>
+#include <linux/sizes.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/clk.h>
+#include <linux/bitops.h>
+#include <linux/of_dma.h>
+
+#include <asm/dma.h>
+#include <asm/irq.h>
+
+#define MSD_CMD_REG 0
+#define MSD_ARG_REG 4
+#define MSD_RESP0_REG 8
+#define MSD_RESP1_REG 0x0c
+#define MSD_RESP2_REG 0x10
+#define MSD_RESP3_REG 0x14
+#define MSD_RESP_CMD_REG 0x18
+#define MSD_DATA_CTRL_REG 0x1c
+#define MSD_DATA_TIMER_REG 0x20
+#define MSD_DATA_LEN_REG 0x24
+#define MSD_STATUS_REG 0x28
+#define MSD_CLEAR_REG 0x2c
+#define MSD_INT_MASK_REG 0x30
+#define MSD_POWER_CTRL_REG 0x34
+#define MSD_CLOCK_CTRL_REG 0x38
+#define MSD_BUS_WIDTH_REG 0x3c
+#define MSD_DATA_WIN_REG 0x40
+#define MSD_FEATURE_REG 0x44
+#define MSD_REVISION_REG 0x48
+
+#define MMC_RSP_SHORT 1
+#define MMC_RSP_LONG 2
+#define MMC_RSP_MASK 3
+#define MMC_ERR_NONE 0
+#define MMC_ERR_TIMEOUT 1
+#define MMC_MODE_MMC 0
+#define MMC_MODE_SD 1
+#define MMC_ERR_BADCRC 2
+#define MMC_VDD_360 23
+
+#define MSD_RETRY_COUNT 10
+
+#define REG_COMMAND 0
+#define REG_ARGUMENT 4
+#define REG_RESPONSE0 8
+#define REG_RESPONSE1 12
+#define REG_RESPONSE2 16
+#define REG_RESPONSE3 20
+#define REG_RESPONSE_COMMAND 24
+#define REG_DATA_CONTROL 28
+#define REG_DATA_TIMER 32
+#define REG_DATA_LENGTH 36
+#define REG_STATUS 40
+#define REG_CLEAR 44
+#define REG_INTERRUPT_MASK 48
+#define REG_POWER_CONTROL 52
+#define REG_CLOCK_CONTROL 56
+#define REG_BUS_WIDTH 60
+#define REG_DATA_WINDOW 64
+#define REG_FEATURE 68
+#define REG_REVISION 72
+
+/* REG_COMMAND */
+#define MSD_SDC_RST BIT(10)
+#define MSD_CMD_EN BIT(9)
+#define MSD_APP_CMD BIT(8)
+#define MSD_LONG_RSP BIT(7)
+#define MSD_NEED_RSP BIT(6)
+#define MSD_CMD_IDX_MASK 0x3f
+
+/* REG_RESPONSE_COMMAND */
+#define MSD_RSP_CMD_APP BIT(6)
+#define MSD_RSP_CMD_IDX_MASK 0x3f
+
+/* REG_DATA_CONTROL */
+#define MSD_DATA_EN BIT(6)
+#define MSD_DMA_EN BIT(5)
+#define MSD_DATA_WRITE BIT(4)
+#define MSD_BLK_SIZE_MASK 0x0f
+
+/* REG_DATA_LENGTH */
+#define MSD_DATA_LEN_MASK 0xffffff
+
+/* REG_STATUS */
+#define MSD_WRITE_PROT BIT(12)
+#define MSD_CARD_DETECT BIT(11)
+/* 1-10 below can be sent to interrupt or clear register */
+#define MSD_CARD_CHANGE BIT(10)
+#define MSD_FIFO_ORUN BIT(9)
+#define MSD_FIFO_URUN BIT(8)
+#define MSD_DATA_END BIT(7)
+#define MSD_CMD_SENT BIT(6)
+#define MSD_DATA_CRC_OK BIT(5)
+#define MSD_RSP_CRC_OK BIT(4)
+#define MSD_DATA_TIMEOUT BIT(3)
+#define MSD_RSP_TIMEOUT BIT(2)
+#define MSD_DATA_CRC_FAIL BIT(1)
+#define MSD_RSP_CRC_FAIL BIT(0)
+
+/* REG_POWER_CONTROL */
+#define MSD_SD_POWER_ON BIT(4)
+#define MSD_SD_POWER_MASK 0x0f
+
+/* REG_CLOCK_CONTROL */
+#define MSD_CLK_DIS BIT(8)
+#define MSD_CLK_SD BIT(7)
+#define MSD_CLK_DIV_MASK 0x7f
+
+/* REG_BUS_WIDTH */
+#define MSD_WIDE_BUS_SUPPORT BIT(3)
+#define MSD_WIDE_BUS BIT(2) /* bus width is 4 bytes */
+#define MSD_SINGLE_BUS BIT(0) /* bus width is 1 byte */
+
+/* REG_FEATURE */
+#define MSD_CPRM_FUNCTION BIT(8)
+
+struct moxart_host {
+ spinlock_t lock;
+ void __iomem *base;
+ phys_addr_t reg_phys;
+
+ struct dma_chan *dma_chan_rx;
+ struct dma_chan *dma_chan_tx;
+ struct dma_async_tx_descriptor *tx_desc;
+ dma_cookie_t cur_dma_cookie;
+ unsigned int dma_direction;
+ bool have_dma;
+ struct completion dma_complete;
+ struct completion pio_complete;
+
+ struct mmc_host *mmc;
+ struct mmc_request *mrq;
+
+ struct scatterlist *cur_sg;
+ unsigned int num_sg;
+ unsigned int remain;
+ int size;
+
+ unsigned int timeout;
+ long sysclk;
+ bool removed;
+};
+
+#define MSD_FIFO_LENW 4 /* 4 words, total 4 * 4 = 16 bytes */
+#define MSD_FIFO_LENB 16 /* 16 bytes */
+
+#define DMA_FIFO_LEN_FORCE 0
+#define MIN_POWER (MMC_VDD_360 - MSD_SD_POWER_MASK)
+
+static inline void moxart_init_sg(struct moxart_host *host,
+ struct mmc_data *data)
+{
+ host->cur_sg = data->sg;
+ host->num_sg = data->sg_len;
+ host->remain = host->cur_sg->length;
+
+ if (host->remain > host->size)
+ host->remain = host->size;
+
+ data->error = MMC_ERR_NONE;
+}
+
+static inline int moxart_next_sg(struct moxart_host *host)
+{
+ int remain;
+ struct mmc_data *data = host->mrq->cmd->data;
+
+ host->cur_sg++;
+ host->num_sg--;
+
+ if (host->num_sg > 0) {
+ host->remain = host->cur_sg->length;
+ remain = host->size - data->bytes_xfered;
+ if (remain > 0 && remain < host->remain)
+ host->remain = remain;
+ }
+
+ return host->num_sg;
+}
+
+static void moxart_send_command(struct moxart_host *host,
+ struct mmc_command *cmd)
+{
+ unsigned int status, cmdctrl;
+ int retry = 0;
+
+ dev_dbg(mmc_dev(host->mmc), "%s: cmd->opcode=%d\n",
+ __func__, cmd->opcode);
+
+ cmd->error = MMC_ERR_TIMEOUT;
+
+ writel(MSD_RSP_TIMEOUT | MSD_RSP_CRC_OK |
+ MSD_RSP_CRC_FAIL | MSD_CMD_SENT, host->base + REG_CLEAR);
+ writel(cmd->arg, host->base + REG_ARGUMENT);
+
+ cmdctrl = cmd->opcode & MSD_CMD_IDX_MASK;
+ if (cmdctrl == SD_APP_SET_BUS_WIDTH || cmdctrl == SD_APP_OP_COND ||
+ cmdctrl == SD_APP_SEND_SCR || cmdctrl == SD_APP_SD_STATUS ||
+ cmdctrl == SD_APP_SEND_NUM_WR_BLKS)
+ cmdctrl |= MSD_APP_CMD;
+
+ if (cmd->flags & MMC_RSP_136)
+ cmdctrl |= (MSD_LONG_RSP | MSD_NEED_RSP);
+ else
+ cmdctrl |= MSD_NEED_RSP;
+
+ writel(cmdctrl | MSD_CMD_EN, host->base + REG_COMMAND);
+
+ while (retry++ < MSD_RETRY_COUNT) {
+ udelay(10);
+ status = readl(host->base + REG_STATUS);
+ if (status & MSD_CARD_DETECT) {
+ dev_dbg(mmc_dev(host->mmc), "%s: MSD_CARD_DETECT\n",
+ __func__);
+ cmd->error = MMC_ERR_TIMEOUT;
+ break;
+ }
+ if (cmdctrl & MSD_NEED_RSP) {
+ dev_dbg(mmc_dev(host->mmc), "%s: MSD_NEED_RSP\n",
+ __func__);
+ if (status & MSD_RSP_TIMEOUT) {
+ dev_dbg(mmc_dev(host->mmc), "%s: MSD_RSP_TIMEOUT\n",
+ __func__);
+ writel(MSD_RSP_TIMEOUT, host->base + REG_CLEAR);
+ cmd->error = MMC_ERR_TIMEOUT;
+ break;
+ }
+ if ((cmd->flags & MMC_RSP_CRC) &&
+ (status & MSD_RSP_CRC_FAIL)) {
+ dev_dbg(mmc_dev(host->mmc), "%s: MSD_RSP_CRC_FAIL\n",
+ __func__);
+ writel(MSD_RSP_CRC_FAIL, host->base +
+ REG_CLEAR);
+ cmd->error = MMC_ERR_BADCRC;
+ break;
+ }
+ if (status & MSD_RSP_CRC_OK) {
+ dev_dbg(mmc_dev(host->mmc), "%s: MSD_RSP_CRC_OK\n",
+ __func__);
+ writel(MSD_RSP_CRC_OK, host->base + REG_CLEAR);
+
+ if (cmd->flags & MMC_RSP_136) {
+ cmd->resp[3] =
+ readl(host->base +
+ REG_RESPONSE0);
+ cmd->resp[2] =
+ readl(host->base +
+ REG_RESPONSE1);
+ cmd->resp[1] =
+ readl(host->base +
+ REG_RESPONSE2);
+ cmd->resp[0] =
+ readl(host->base +
+ REG_RESPONSE3);
+ } else {
+ cmd->resp[0] =
+ readl(host->base +
+ REG_RESPONSE0);
+ }
+
+ cmd->error = MMC_ERR_NONE;
+ break;
+ }
+ } else {
+ dev_dbg(mmc_dev(host->mmc), "%s: !(cmdctrl & MSD_NEED_RSP)\n",
+ __func__);
+ if (status & MSD_CMD_SENT) {
+ writel(MSD_CMD_SENT, host->base + REG_CLEAR);
+ cmd->error = MMC_ERR_NONE;
+ break;
+ }
+ }
+ }
+
+ if (retry >= (MSD_RETRY_COUNT - 1)) {
+ /*
+ * this seems to happen a lot on or after CMD25
+ * (MMC_WRITE_MULTIPLE_BLOCK) with more than 4 blocks
+ * (>4096), possibly because the transfer is too big
+ * or takes too long to complete.
+ * when this happens the controller is usually rendered
+ * unresponsive and can only be recovered with reboot.
+ */
+ dev_dbg(mmc_dev(host->mmc), "%s: WARNING! no valid status found!\n",
+ __func__);
+ }
+}
+
+static void moxart_dma_complete(void *param)
+{
+ struct moxart_host *host = param;
+ struct dma_chan *chan = host->tx_desc->chan;
+ struct dma_tx_state txs;
+
+ if (dmaengine_tx_status(chan, host->cur_dma_cookie, &txs) == DMA_ERROR)
+ dev_err_ratelimited(mmc_dev(host->mmc), "%s: DMA error\n",
+ __func__);
+
+ dev_dbg(mmc_dev(host->mmc), "%s: host=%p\n", __func__, host);
+
+ complete(&host->dma_complete);
+}
+
+static void moxart_transfer_dma(struct mmc_data *data, struct moxart_host *host)
+{
+ unsigned int len, direction_dev;
+ struct dma_async_tx_descriptor *desc = NULL;
+ struct dma_chan *dma_chan_cur;
+
+ if (host->size == data->bytes_xfered)
+ return;
+
+ if (data->flags & MMC_DATA_WRITE) {
+ direction_dev = DMA_MEM_TO_DEV;
+ dma_chan_cur = host->dma_chan_tx;
+ } else {
+ direction_dev = DMA_DEV_TO_MEM;
+ dma_chan_cur = host->dma_chan_rx;
+ }
+
+ /*
+ * because dma_map_sg takes both sg and sg_len as arguments
+ * (and maps the entire list of buffers) data->sg does not
+ * have to be incremented between calls (as is required
+ * in moxart_transfer_pio)
+ */
+ len = dma_map_sg(dma_chan_cur->device->dev, data->sg,
+ data->sg_len, host->dma_direction);
+
+ if (len > 0) {
+ desc = dmaengine_prep_slave_sg(dma_chan_cur, data->sg,
+ len, direction_dev,
+ DMA_PREP_INTERRUPT |
+ DMA_CTRL_ACK);
+ } else {
+ dev_err(mmc_dev(host->mmc),
+ "%s: dma_map_sg returned zero length\n",
+ __func__);
+ }
+
+ if (desc) {
+ host->tx_desc = desc;
+ desc->callback = moxart_dma_complete;
+ desc->callback_param = host;
+ host->cur_dma_cookie = dmaengine_submit(desc);
+ dma_async_issue_pending(dma_chan_cur);
+ }
+
+ data->bytes_xfered += host->remain;
+}
+
+/* when DMA is available this is used only for SD_APP_SEND_SCR */
+static void moxart_transfer_pio(struct moxart_host *host)
+{
+ unsigned char *buffer;
+ unsigned int wcnt, i;
+ struct mmc_data *data = host->mrq->cmd->data;
+
+ if (host->size == data->bytes_xfered)
+ goto transfer_complete;
+
+ buffer = sg_virt(host->cur_sg);
+ wcnt = host->remain >> 2;
+
+ if (data->flags & MMC_DATA_WRITE) {
+ for (i = 0; i < wcnt; i++, buffer += 4) {
+ writel(*(unsigned int *)buffer,
+ host->base + REG_DATA_WINDOW);
+ udelay(10);
+ }
+ } else {
+ for (i = 0; i < wcnt; i++, buffer += 4) {
+ /* byte order reversed only when reading SCR */
+ if (data->mrq->cmd->opcode == SD_APP_SEND_SCR) {
+ *(unsigned int *)buffer = ioread32be(
+ host->base + REG_DATA_WINDOW);
+ } else {
+ *(unsigned int *)buffer =
+ readl(host->base + REG_DATA_WINDOW);
+ }
+ udelay(10);
+ }
+ }
+ wcnt <<= 2;
+ host->remain -= wcnt;
+ data->bytes_xfered += wcnt;
+
+ if (host->size != data->bytes_xfered) {
+ moxart_next_sg(host);
+ /*
+ * used to goto "transfer_start" label here,
+ * there is no need, this function will be
+ * called again from interrupt.
+ *
+ * compare with DMA where sg increment is
+ * redundant thanks to dma_map_sg
+ */
+ } else {
+ complete(&host->pio_complete);
+ }
+
+transfer_complete:
+ dev_dbg(mmc_dev(host->mmc), "%s: host->size=%d host->remain=%u\n",
+ __func__, host->size, host->remain);
+}
+
+static void moxart_prepare_data(struct moxart_host *host)
+{
+ struct mmc_data *data = host->mrq->cmd->data;
+ unsigned int timeout, datactrl;
+ int blksz_bits;
+
+ dev_dbg(mmc_dev(host->mmc), "%s\n", __func__);
+
+ if (!data)
+ return;
+
+ host->size = data->blocks * data->blksz;
+ blksz_bits = ffs(data->blksz) - 1;
+ BUG_ON(1 << blksz_bits != data->blksz);
+
+ moxart_init_sg(host, data);
+
+ timeout = (host->mmc->f_max / 1000) * (data->timeout_ns / 1000);
+ timeout *= 2;
+
+ datactrl = (blksz_bits & MSD_BLK_SIZE_MASK) | MSD_DATA_EN;
+
+ if (data->flags & MMC_DATA_WRITE)
+ datactrl |= MSD_DATA_WRITE;
+
+ if (((host->size > MSD_FIFO_LENB) || DMA_FIFO_LEN_FORCE)
+ && host->have_dma) {
+ datactrl |= MSD_DMA_EN;
+ }
+
+ dev_dbg(mmc_dev(host->mmc), "%s: blocks=%d blksz=%d datactrl=0x%08x\n",
+ __func__, data->blocks, data->blksz, datactrl);
+ dev_dbg(mmc_dev(host->mmc), "%s: timeout=%u timeout_ns=%u\n",
+ __func__, timeout, data->timeout_ns);
+
+ writel(timeout, host->base + REG_DATA_TIMER);
+ writel(host->size, host->base + REG_DATA_LENGTH);
+ writel(datactrl, host->base + REG_DATA_CONTROL);
+}
+
+static void moxart_transfer_check(struct mmc_data *data,
+ struct moxart_host *host)
+{
+ unsigned int status, count = 0;
+
+ dev_dbg(mmc_dev(host->mmc), "%s\n", __func__);
+
+ while (1) {
+ udelay(10);
+ status = readl(host->base + REG_STATUS);
+ if (status & (MSD_DATA_CRC_OK | MSD_DATA_CRC_FAIL
+ | MSD_DATA_END) || count > 10)
+ break;
+ dev_dbg(mmc_dev(host->mmc), "%s: waiting for status=%08x ..\n",
+ __func__, status);
+ count++;
+ }
+ if (status & MSD_DATA_CRC_OK) {
+ dev_dbg(mmc_dev(host->mmc), "%s: MSD_DATA_CRC_OK\n", __func__);
+ writel(MSD_DATA_CRC_OK, host->base + REG_CLEAR);
+ }
+ if (status & MSD_DATA_CRC_FAIL) {
+ dev_dbg(mmc_dev(host->mmc), "%s: MSD_DATA_CRC_FAIL\n",
+ __func__);
+ writel(MSD_DATA_CRC_FAIL, host->base + REG_CLEAR);
+ data->error = MMC_ERR_TIMEOUT;
+ }
+ if (status & MSD_DATA_END) {
+ dev_dbg(mmc_dev(host->mmc), "%s: MSD_DATA_END\n",
+ __func__);
+ writel(MSD_DATA_END, host->base + REG_CLEAR);
+ }
+ if (status & MSD_DATA_TIMEOUT) {
+ dev_dbg(mmc_dev(host->mmc), "%s: MSD_DATA_TIMEOUT\n",
+ __func__);
+ writel(MSD_DATA_TIMEOUT, host->base + REG_CLEAR);
+ }
+}
+
+static void moxart_card_change(struct moxart_host *host)
+{
+ int delay;
+ unsigned long flags;
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ if (readl(host->base + REG_STATUS) & MSD_CARD_DETECT) {
+ dev_dbg(mmc_dev(host->mmc), "%s: card removed\n", __func__);
+ if (host->have_dma && host->size > MSD_FIFO_LENB) {
+ dev_dbg(mmc_dev(host->mmc), "%s: call dmaengine_terminate_all\n",
+ __func__);
+ dmaengine_terminate_all(host->dma_chan_rx);
+ dmaengine_terminate_all(host->dma_chan_tx);
+ }
+ host->removed = true;
+ delay = 0;
+ } else {
+ dev_dbg(mmc_dev(host->mmc), "%s: card inserted\n", __func__);
+ host->removed = false;
+ delay = 500;
+ }
+
+ /*
+ * clearing FIFO interrupts here does not stop a follow up
+ * MSD_FIFO_*RUN after MSD_CARD_CHANGE. instead, check
+ * host->mrq != NULL in moxart_irq to avoid unnecessary calls
+ * to moxart_transfer_pio
+ * if this happens during transfer the mmc_request in
+ * moxart_request should still be valid
+ * (which is why host->mrq can be set NULL here)
+ */
+ host->mrq = NULL;
+ writel(MSD_CARD_CHANGE | MSD_FIFO_ORUN | MSD_FIFO_URUN,
+ host->base + REG_CLEAR);
+ writel(MSD_CARD_CHANGE, host->base + REG_INTERRUPT_MASK);
+
+ spin_unlock_irqrestore(&host->lock, flags);
+ dev_dbg(mmc_dev(host->mmc), "%s: call mmc_detect_change\n", __func__);
+ mmc_detect_change(host->mmc, msecs_to_jiffies(delay));
+}
+
+static void moxart_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+ struct moxart_host *host = mmc_priv(mmc);
+ unsigned long dma_time, pio_time, flags;
+ unsigned int status;
+
+ dev_dbg(mmc_dev(host->mmc), "%s\n", __func__);
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ init_completion(&host->dma_complete);
+ init_completion(&host->pio_complete);
+
+ host->mrq = mrq;
+
+ if (readl(host->base + REG_STATUS) & MSD_CARD_DETECT) {
+ mrq->cmd->error = MMC_ERR_TIMEOUT;
+ goto request_done;
+ }
+
+ moxart_prepare_data(host);
+ moxart_send_command(host, host->mrq->cmd);
+
+ if (mrq->cmd->data) {
+ /* only use DMA/PIO (and wait) when there is data */
+ if (((host->size > MSD_FIFO_LENB) || DMA_FIFO_LEN_FORCE)
+ && host->have_dma) {
+
+ writel(MSD_CARD_CHANGE, host->base +
+ REG_INTERRUPT_MASK);
+
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ host->dma_direction = (mrq->cmd->data->flags
+ & MMC_DATA_WRITE) ?
+ DMA_TO_DEVICE : DMA_FROM_DEVICE;
+ moxart_transfer_dma(mrq->cmd->data, host);
+
+ dma_time = wait_for_completion_interruptible_timeout(
+ &host->dma_complete, host->timeout);
+ dev_dbg(mmc_dev(host->mmc), "%s: dma_time=%lu (DMA wait time)\n",
+ __func__, dma_time);
+
+ dma_unmap_sg(host->dma_chan_tx->device->dev,
+ mrq->cmd->data->sg, mrq->cmd->data->sg_len,
+ host->dma_direction);
+
+ spin_lock_irqsave(&host->lock, flags);
+ } else {
+
+ writel(MSD_FIFO_URUN | MSD_FIFO_ORUN | MSD_CARD_CHANGE,
+ host->base + REG_INTERRUPT_MASK);
+
+ status = readl(host->base + REG_STATUS);
+ dev_dbg(mmc_dev(host->mmc), "%s: status=%08x\n",
+ __func__, status);
+
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ /* PIO transfer started from interrupt */
+ pio_time = wait_for_completion_interruptible_timeout(
+ &host->pio_complete, host->timeout);
+ dev_dbg(mmc_dev(host->mmc), "%s: pio_time=%lu (PIO wait time)\n",
+ __func__, pio_time);
+
+ spin_lock_irqsave(&host->lock, flags);
+ }
+
+ /* removed during transfer? (interrupts were just enabled..) */
+ if (host->removed) {
+ dev_dbg(mmc_dev(host->mmc), "%s: host removed during transfer!\n",
+ __func__);
+ mrq->cmd->error = MMC_ERR_TIMEOUT;
+ }
+
+ moxart_transfer_check(mrq->cmd->data, host);
+
+ if (mrq->cmd->data->stop)
+ moxart_send_command(host, mrq->cmd->data->stop);
+ }
+
+request_done:
+ spin_unlock_irqrestore(&host->lock, flags);
+ mmc_request_done(host->mmc, mrq);
+}
+
+static irqreturn_t moxart_irq(int irq, void *devid)
+{
+ struct moxart_host *host = (struct moxart_host *)devid;
+ unsigned int status;
+ unsigned long flags;
+
+ status = readl(host->base + REG_STATUS);
+
+ dev_dbg(mmc_dev(host->mmc), "%s: host=%p status=%08x\n",
+ __func__, host, status);
+
+ if (status & MSD_CARD_CHANGE) {
+ dev_dbg(mmc_dev(host->mmc), "%s: call moxart_card_change\n",
+ __func__);
+ moxart_card_change(host);
+ }
+ if (status & (MSD_FIFO_ORUN | MSD_FIFO_URUN) && host->mrq) {
+ writel(status & (MSD_FIFO_ORUN | MSD_FIFO_URUN),
+ host->base + REG_CLEAR);
+ dev_dbg(mmc_dev(host->mmc), "%s: call moxart_transfer_pio\n",
+ __func__);
+ spin_lock_irqsave(&host->lock, flags);
+ moxart_transfer_pio(host);
+ spin_unlock_irqrestore(&host->lock, flags);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static void moxart_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+ struct moxart_host *host = mmc_priv(mmc);
+ unsigned long flags;
+ unsigned short power;
+ int div;
+
+ spin_lock_irqsave(&host->lock, flags);
+ if (ios->clock) {
+ div = (host->sysclk / (host->mmc->f_max * 2)) - 1;
+
+ if (div > MSD_CLK_DIV_MASK)
+ div = MSD_CLK_DIV_MASK;
+ else if (div < 0)
+ div = 0;
+
+ div |= MSD_CLK_SD;
+ writel(div, host->base + REG_CLOCK_CONTROL);
+ } else if (!(readl(host->base + REG_CLOCK_CONTROL) & MSD_CLK_DIS)) {
+ writel(readl(host->base + REG_CLOCK_CONTROL) | MSD_CLK_DIS,
+ host->base + REG_CLOCK_CONTROL);
+ }
+
+ if (ios->power_mode == MMC_POWER_OFF) {
+ writel(readl(host->base + REG_POWER_CONTROL) & ~MSD_SD_POWER_ON,
+ host->base + REG_POWER_CONTROL);
+ } else {
+ if (ios->vdd < MIN_POWER)
+ power = 0;
+ else
+ power = ios->vdd - MIN_POWER;
+
+ writel(MSD_SD_POWER_ON | (unsigned int) power,
+ host->base + REG_POWER_CONTROL);
+ }
+
+ if (ios->bus_width == MMC_BUS_WIDTH_1)
+ writel(MSD_SINGLE_BUS, host->base + REG_BUS_WIDTH);
+ else
+ writel(MSD_WIDE_BUS, host->base + REG_BUS_WIDTH);
+
+ spin_unlock_irqrestore(&host->lock, flags);
+}
+
+
+static int moxart_get_ro(struct mmc_host *mmc)
+{
+ struct moxart_host *host = mmc_priv(mmc);
+
+ return !!(readl(host->base + REG_STATUS) & MSD_WRITE_PROT);
+}
+
+static struct mmc_host_ops moxart_ops = {
+ .request = moxart_request,
+ .set_ios = moxart_set_ios,
+ .get_ro = moxart_get_ro,
+};
+
+static int moxart_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+ struct resource res_mmc;
+ struct mmc_host *mmc;
+ struct moxart_host *host = NULL;
+ void __iomem *reg_mmc;
+ dma_cap_mask_t mask;
+ int ret;
+ struct dma_slave_config cfg;
+ unsigned int irq;
+ struct clk *clk;
+
+ mmc = mmc_alloc_host(sizeof(struct moxart_host), dev);
+ if (!mmc) {
+ dev_err(dev, "%s: mmc_alloc_host failed\n", __func__);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = of_address_to_resource(node, 0, &res_mmc);
+ if (ret) {
+ dev_err(dev, "%s: could not get MMC base resource\n", __func__);
+ goto out;
+ }
+
+ irq = irq_of_parse_and_map(node, 0);
+ if (irq <= 0) {
+ dev_err(dev, "irq_of_parse_and_map failed\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ reg_mmc = devm_ioremap_resource(dev, &res_mmc);
+ if (IS_ERR(reg_mmc))
+ return PTR_ERR(reg_mmc);
+
+ mmc->ops = &moxart_ops;
+
+ /*
+ * hardware does not support MMC_CAP_SD_HIGHSPEED
+ * CMD6 will timeout and make things not work
+ */
+ mmc->caps = MMC_CAP_4_BIT_DATA;
+
+ mmc->f_min = 400000;
+ mmc->f_max = 25000000;
+ mmc->ocr_avail = 0xffff00; /* support 2.0v - 3.6v power */
+ mmc->max_segs = 32;
+ mmc->max_blk_size = 512;
+ mmc->max_blk_count = mmc->max_req_size / mmc->max_blk_size;
+ mmc->max_seg_size = mmc->max_req_size;
+
+ host = mmc_priv(mmc);
+ host->mmc = mmc;
+ host->base = reg_mmc;
+ host->reg_phys = res_mmc.start;
+ host->timeout = msecs_to_jiffies(1000);
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ clk = of_clk_get(node, 0);
+ if (IS_ERR(clk)) {
+ dev_err(dev, "%s: of_clk_get failed\n", __func__);
+ return PTR_ERR(clk);
+ }
+ host->sysclk = clk_get_rate(clk);
+
+ spin_lock_init(&host->lock);
+
+ /* disable all interrupt */
+ writel(0, host->base + REG_INTERRUPT_MASK);
+
+ /* reset chip */
+ writel(MSD_SDC_RST, host->base + REG_COMMAND);
+
+ /* wait for reset finished */
+ while (readl(host->base + REG_COMMAND) & MSD_SDC_RST)
+ udelay(10);
+
+ host->dma_chan_tx = of_dma_request_slave_channel(node, "tx");
+ host->dma_chan_rx = of_dma_request_slave_channel(node, "rx");
+
+ if (!host->dma_chan_rx || !host->dma_chan_tx) {
+ dev_dbg(dev, "%s: using PIO mode transfer\n", __func__);
+
+ host->have_dma = false;
+ mmc->max_blk_count = 1;
+ } else {
+ dev_dbg(dev, "%s: using 2 DMA channels rx=%p tx=%p\n",
+ __func__, host->dma_chan_rx, host->dma_chan_tx);
+
+ cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+ cfg.direction = DMA_MEM_TO_DEV;
+ cfg.src_addr = 0;
+ cfg.dst_addr = (unsigned int)host->reg_phys + MSD_DATA_WIN_REG;
+ dmaengine_slave_config(host->dma_chan_tx, &cfg);
+
+ cfg.direction = DMA_DEV_TO_MEM;
+ cfg.src_addr = (unsigned int)host->reg_phys + MSD_DATA_WIN_REG;
+ cfg.dst_addr = 0;
+ dmaengine_slave_config(host->dma_chan_rx, &cfg);
+
+ host->have_dma = true;
+
+ /*
+ * there seems to be a max size on transfers so
+ * set max_blk_count low for both DMA and PIO
+ *
+ * sending large chunks result either in timeout
+ * or render the MMC controller unresponsive
+ * (status register 0 on consecutive read retries,
+ * also see comments in moxart_send_command)
+ *
+ * obviously, DMA is quicker and can handle
+ * larger chunks but setting it higher than 16
+ * can still bug the controller
+ */
+ mmc->max_blk_count = 16;
+ }
+
+ ret = devm_request_irq(dev, irq, moxart_irq, 0, "moxart-mmc", host);
+
+ if (ret)
+ goto out;
+
+ dev_set_drvdata(dev, mmc);
+ mmc_add_host(mmc);
+
+ dev_dbg(dev, "%s: IRQ=%d\n", __func__, irq);
+
+ return 0;
+
+out:
+ if (mmc)
+ mmc_free_host(mmc);
+ return ret;
+}
+
+static void moxart_release_dma(struct moxart_host *host)
+{
+ if (host->dma_chan_tx) {
+ struct dma_chan *chan = host->dma_chan_tx;
+ host->dma_chan_tx = NULL;
+ dma_release_channel(chan);
+ }
+ if (host->dma_chan_rx) {
+ struct dma_chan *chan = host->dma_chan_rx;
+ host->dma_chan_rx = NULL;
+ dma_release_channel(chan);
+ }
+}
+
+static int moxart_remove(struct platform_device *pdev)
+{
+ struct mmc_host *mmc = dev_get_drvdata(&pdev->dev);
+ struct moxart_host *host = mmc_priv(mmc);
+
+ dev_set_drvdata(&pdev->dev, NULL);
+
+ if (mmc) {
+ moxart_release_dma(host);
+ mmc_remove_host(mmc);
+ mmc_free_host(mmc);
+
+ writel(0, host->base + REG_INTERRUPT_MASK);
+ writel(0, host->base + REG_POWER_CONTROL);
+ writel(readl(host->base + REG_CLOCK_CONTROL) | MSD_CLK_DIS,
+ host->base + REG_CLOCK_CONTROL);
+ }
+
+ kfree(host);
+
+ return 0;
+}
+
+static const struct of_device_id moxart_sdhci_match[] = {
+ { .compatible = "moxa,moxart-sdhci" },
+ { }
+};
+
+static struct platform_driver moxart_sdhci_driver = {
+ .probe = moxart_probe,
+ .remove = moxart_remove,
+ .driver = {
+ .name = "sdhci-moxart",
+ .owner = THIS_MODULE,
+ .of_match_table = moxart_sdhci_match,
+ },
+};
+module_platform_driver(moxart_sdhci_driver);
+
+MODULE_ALIAS("platform:sdhci-moxart");
+MODULE_DESCRIPTION("MOXART SDHCI driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jonas Jensen <jonas.jensen@xxxxxxxxx>");
--
1.8.2.1

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