2010-04-27 10:15:47

by Yusuke Goda

[permalink] [raw]
Subject: [PATCH 1/2] MMC: Add support MMCIF for SuperH


MMCIF is MMC Host Interface in SuperH.

Signed-off-by: Yusuke Goda <[email protected]>
---
drivers/mmc/host/Kconfig | 8 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/sh_mmcif.c | 964 ++++++++++++++++++++++++++++++++++++++++++
include/linux/mmc/sh_mmcif.h | 39 ++
4 files changed, 1012 insertions(+), 0 deletions(-)
create mode 100644 drivers/mmc/host/sh_mmcif.c
create mode 100644 include/linux/mmc/sh_mmcif.h

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 2e13b94..aeecbc9 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -412,3 +412,11 @@ config SDH_BFIN_MISSING_CMD_PULLUP_WORKAROUND
depends on SDH_BFIN
help
If you say yes here SD-Cards may work on the EZkit.
+
+config MMC_SH_MMCIF
+ tristate "SuperH Internal MMCIF support"
+ depends on MMC_BLOCK && (SUPERH || ARCH_SHMOBILE)
+ help
+ This selects the MMC Host Interface controler (MMCIF).
+
+ This driver supports MMCIF in sh7724/sh7757/sh7372.
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index f480397..2447b66 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_MMC_TMIO) += tmio_mmc.o
obj-$(CONFIG_MMC_CB710) += cb710-mmc.o
obj-$(CONFIG_MMC_VIA_SDMMC) += via-sdmmc.o
obj-$(CONFIG_SDH_BFIN) += bfin_sdh.o
+obj-$(CONFIG_MMC_SH_MMCIF) += sh_mmcif.o

obj-$(CONFIG_MMC_SDHCI_OF) += sdhci-of.o
sdhci-of-y := sdhci-of-core.o
diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
new file mode 100644
index 0000000..4a62c96
--- /dev/null
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -0,0 +1,964 @@
+/*
+ * MMCIF eMMC driver.
+ *
+ * Copyright (C) 2010 Renesas Solutions Corp.
+ * Yusuke Goda <[email protected]>
+ *
+ * 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.
+ *
+ *
+ * TODO
+ * 1. DMA
+ * 2. Power management
+ * 3. Handle MMC errors better
+ *
+ */
+
+#include <linux/dma-mapping.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
+#include <linux/mmc/core.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/sdio.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/mmc/sh_mmcif.h>
+
+#define DRIVER_NAME "sh_mmcif"
+#define DRIVER_VERSION "2010-04-27"
+
+#define MMCIF_CE_CMD_SET 0x00000000
+#define MMCIF_CE_ARG 0x00000008
+#define MMCIF_CE_ARG_CMD12 0x0000000C
+#define MMCIF_CE_CMD_CTRL 0x00000010
+#define MMCIF_CE_BLOCK_SET 0x00000014
+#define MMCIF_CE_CLK_CTRL 0x00000018
+#define MMCIF_CE_BUF_ACC 0x0000001C
+#define MMCIF_CE_RESP3 0x00000020
+#define MMCIF_CE_RESP2 0x00000024
+#define MMCIF_CE_RESP1 0x00000028
+#define MMCIF_CE_RESP0 0x0000002C
+#define MMCIF_CE_RESP_CMD12 0x00000030
+#define MMCIF_CE_DATA 0x00000034
+#define MMCIF_CE_INT 0x00000040
+#define MMCIF_CE_INT_MASK 0x00000044
+#define MMCIF_CE_HOST_STS1 0x00000048
+#define MMCIF_CE_HOST_STS2 0x0000004C
+#define MMCIF_CE_VERSION 0x0000007C
+
+/* CE_CMD_SET */
+#define CMD_MASK 0x3f000000
+#define CMD_SET_RTYP_NO ((0 << 23) | (0 << 22))
+#define CMD_SET_RTYP_6B ((0 << 23) | (1 << 22)) /* R1/R1b/R3/R4/R5 */
+#define CMD_SET_RTYP_17B ((1 << 23) | (0 << 22)) /* R2 */
+#define CMD_SET_RBSY (1 << 21) /* R1b */
+#define CMD_SET_CCSEN (1 << 20)
+#define CMD_SET_WDAT (1 << 19) /* 1: on data, 0: no data */
+#define CMD_SET_DWEN (1 << 18) /* 1: write, 0: read */
+#define CMD_SET_CMLTE (1 << 17) /* 1: multi block trans, 0: single */
+#define CMD_SET_CMD12EN (1 << 16) /* 1: CMD12 auto issue */
+#define CMD_SET_RIDXC_INDEX ((0 << 15) | (0 << 14)) /* index check */
+#define CMD_SET_RIDXC_BITS ((0 << 15) | (1 << 14)) /* check bits check */
+#define CMD_SET_RIDXC_NO ((1 << 15) | (0 << 14)) /* no check */
+#define CMD_SET_CRC7C ((0 << 13) | (0 << 12)) /* CRC7 check*/
+#define CMD_SET_CRC7C_BITS ((0 << 13) | (1 << 12)) /* check bits check*/
+#define CMD_SET_CRC7C_INTERNAL ((1 << 13) | (0 << 12)) /* internal CRC7 check*/
+#define CMD_SET_CRC16C (1 << 10) /* 0: CRC16 check*/
+#define CMD_SET_CRCSTE (1 << 8) /* 1: not receive CRC status */
+#define CMD_SET_TBIT (1 << 7) /* 1: tran mission bit "Low" */
+#define CMD_SET_OPDM (1 << 6) /* 1: open/drain */
+#define CMD_SET_CCSH (1 << 5)
+#define CMD_SET_DATW_1 ((0 << 1) | (0 << 0)) /* 1bit */
+#define CMD_SET_DATW_4 ((0 << 1) | (1 << 0)) /* 4bit */
+#define CMD_SET_DATW_8 ((1 << 1) | (0 << 0)) /* 8bit */
+
+/* CE_CMD_CTRL */
+#define CMD_CTRL_BREAK (1 << 0)
+
+/* CE_BLOCK_SET */
+#define BLOCK_SIZE_MASK 0x0000ffff
+
+/* CE_CLK_CTRL */
+#define CLK_ENABLE (1 << 24) /* 1: output mmc clock */
+#define CLK_CLEAR ((1 << 19) | (1 << 18) | (1 << 17) | (1 << 16))
+#define CLK_SUP_PCLK ((1 << 19) | (1 << 18) | (1 << 17) | (1 << 16))
+#define SRSPTO_256 ((1 << 13) | (0 << 12)) /* resp timeout */
+#define SRBSYTO_29 ((1 << 11) | (1 << 10) | \
+ (1 << 9) | (1 << 8)) /* resp busy timeout */
+#define SRWDTO_29 ((1 << 7) | (1 << 6) | \
+ (1 << 5) | (1 << 4)) /* read/write timeout */
+#define SCCSTO_29 ((1 << 3) | (1 << 2) | \
+ (1 << 1) | (1 << 0)) /* ccs timeout */
+
+/* CE_BUF_ACC */
+#define BUF_ACC_DMAWEN (1 << 25)
+#define BUF_ACC_DMAREN (1 << 24)
+#define BUF_ACC_BUSW_32 (0 << 17)
+#define BUF_ACC_BUSW_16 (1 << 17)
+#define BUF_ACC_ATYP (1 << 16)
+
+/* CE_INT */
+#define INT_CCSDE (1 << 29)
+#define INT_CMD12DRE (1 << 26)
+#define INT_CMD12RBE (1 << 25)
+#define INT_CMD12CRE (1 << 24)
+#define INT_DTRANE (1 << 23)
+#define INT_BUFRE (1 << 22)
+#define INT_BUFWEN (1 << 21)
+#define INT_BUFREN (1 << 20)
+#define INT_CCSRCV (1 << 19)
+#define INT_RBSYE (1 << 17)
+#define INT_CRSPE (1 << 16)
+#define INT_CMDVIO (1 << 15)
+#define INT_BUFVIO (1 << 14)
+#define INT_WDATERR (1 << 11)
+#define INT_RDATERR (1 << 10)
+#define INT_RIDXERR (1 << 9)
+#define INT_RSPERR (1 << 8)
+#define INT_CCSTO (1 << 5)
+#define INT_CRCSTO (1 << 4)
+#define INT_WDATTO (1 << 3)
+#define INT_RDATTO (1 << 2)
+#define INT_RBSYTO (1 << 1)
+#define INT_RSPTO (1 << 0)
+#define INT_ERR_STS (INT_CMDVIO | INT_BUFVIO | INT_WDATERR | \
+ INT_RDATERR | INT_RIDXERR | INT_RSPERR | \
+ INT_CCSTO | INT_CRCSTO | INT_WDATTO | \
+ INT_RDATTO | INT_RBSYTO | INT_RSPTO)
+
+/* CE_INT_MASK */
+#define MASK_ALL 0x00000000
+#define MASK_MCCSDE (1 << 29)
+#define MASK_MCMD12DRE (1 << 26)
+#define MASK_MCMD12RBE (1 << 25)
+#define MASK_MCMD12CRE (1 << 24)
+#define MASK_MDTRANE (1 << 23)
+#define MASK_MBUFRE (1 << 22)
+#define MASK_MBUFWEN (1 << 21)
+#define MASK_MBUFREN (1 << 20)
+#define MASK_MCCSRCV (1 << 19)
+#define MASK_MRBSYE (1 << 17)
+#define MASK_MCRSPE (1 << 16)
+#define MASK_MCMDVIO (1 << 15)
+#define MASK_MBUFVIO (1 << 14)
+#define MASK_MWDATERR (1 << 11)
+#define MASK_MRDATERR (1 << 10)
+#define MASK_MRIDXERR (1 << 9)
+#define MASK_MRSPERR (1 << 8)
+#define MASK_MCCSTO (1 << 5)
+#define MASK_MCRCSTO (1 << 4)
+#define MASK_MWDATTO (1 << 3)
+#define MASK_MRDATTO (1 << 2)
+#define MASK_MRBSYTO (1 << 1)
+#define MASK_MRSPTO (1 << 0)
+
+/* CE_HOST_STS1 */
+#define STS1_CMDSEQ (1 << 31)
+
+/* CE_HOST_STS2 */
+#define STS2_CRCSTE (1 << 31)
+#define STS2_CRC16E (1 << 30)
+#define STS2_AC12CRCE (1 << 29)
+#define STS2_RSPCRC7E (1 << 28)
+#define STS2_CRCSTEBE (1 << 27)
+#define STS2_RDATEBE (1 << 26)
+#define STS2_AC12REBE (1 << 25)
+#define STS2_RSPEBE (1 << 24)
+#define STS2_AC12IDXE (1 << 23)
+#define STS2_RSPIDXE (1 << 22)
+#define STS2_CCSTO (1 << 15)
+#define STS2_RDATTO (1 << 14)
+#define STS2_DATBSYTO (1 << 13)
+#define STS2_CRCSTTO (1 << 12)
+#define STS2_AC12BSYTO (1 << 11)
+#define STS2_RSPBSYTO (1 << 10)
+#define STS2_AC12RSPTO (1 << 9)
+#define STS2_RSPTO (1 << 8)
+#define STS2_CRC_ERR (STS2_CRCSTE | STS2_CRC16E | \
+ STS2_AC12CRCE | STS2_RSPCRC7E | STS2_CRCSTEBE)
+#define STS2_TIMEOUT_ERR (STS2_CCSTO | STS2_RDATTO | \
+ STS2_DATBSYTO | STS2_CRCSTTO | \
+ STS2_AC12BSYTO | STS2_RSPBSYTO | \
+ STS2_AC12RSPTO | STS2_RSPTO)
+
+/* CE_VERSION */
+#define SOFT_RST_ON (1 << 31)
+#define SOFT_RST_OFF (0 << 31)
+
+#define CLKDEV_EMMC_DATA 52000000 /* 52MHz */
+#define CLKDEV_MMC_DATA 20000000 /* 20MHz */
+#define CLKDEV_INIT 400000 /* 400 KHz */
+
+struct sh_mmcif_host {
+ struct mmc_host *mmc;
+ struct mmc_data *data;
+ struct mmc_command *cmd;
+ struct platform_device *pd;
+ struct clk *hclk;
+ unsigned int clk;
+ int bus_width;
+ u16 wait_int;
+ u16 sd_error;
+ long timeout;
+ void __iomem *addr;
+ wait_queue_head_t intr_wait;
+};
+
+static inline u32 sh_mmcif_readl(struct sh_mmcif_host *host, unsigned int reg)
+{
+ return readl(host->addr + reg);
+}
+
+static inline void sh_mmcif_writel(struct sh_mmcif_host *host,
+ unsigned int reg, u32 val)
+{
+ writel(val, host->addr + reg);
+}
+
+static inline void sh_mmcif_bitset(struct sh_mmcif_host *host,
+ unsigned int reg, u32 val)
+{
+ writel(val | sh_mmcif_readl(host, reg), host->addr + reg);
+}
+
+static inline void sh_mmcif_bitclr(struct sh_mmcif_host *host,
+ unsigned int reg, u32 val)
+{
+ writel(~val & sh_mmcif_readl(host, reg), host->addr + reg);
+}
+
+
+static void sh_mmcif_clock_control(struct sh_mmcif_host *host, unsigned int clk)
+{
+ int i;
+ struct sh_mmcif_plat_data *p = host->pd->dev.platform_data;
+
+ sh_mmcif_bitclr(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE);
+ sh_mmcif_bitclr(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR);
+
+ if (!clk)
+ return;
+ if (p->sup_pclk && clk == host->clk) {
+ sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_SUP_PCLK);
+ } else {
+ for (i = 1; (unsigned int)host->clk / (1 << i) >= clk; i++)
+ ;
+ sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, (i - 1) << 16);
+ }
+ sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE);
+}
+
+static void sh_mmcif_sync_reset(struct sh_mmcif_host *host)
+{
+ u32 tmp;
+
+ tmp = 0x010f0000 & sh_mmcif_readl(host, MMCIF_CE_CLK_CTRL);
+
+ sh_mmcif_writel(host, MMCIF_CE_VERSION, SOFT_RST_ON);
+ sh_mmcif_writel(host, MMCIF_CE_VERSION, SOFT_RST_OFF);
+ sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, tmp |
+ SRSPTO_256 | SRBSYTO_29 | SRWDTO_29 | SCCSTO_29);
+ /* byte swap on */
+ sh_mmcif_bitset(host, MMCIF_CE_BUF_ACC, BUF_ACC_ATYP);
+}
+
+static int sh_mmcif_error_manage(struct sh_mmcif_host *host)
+{
+ u32 state1, state2;
+ int ret, timeout = 10000000;
+
+ host->sd_error = 0;
+ host->wait_int = 0;
+
+ state1 = sh_mmcif_readl(host, MMCIF_CE_HOST_STS1);
+ state2 = sh_mmcif_readl(host, MMCIF_CE_HOST_STS2);
+ pr_debug("%s: ERR HOST_STS1 = %08x\n", \
+ DRIVER_NAME, sh_mmcif_readl(host, MMCIF_CE_HOST_STS1));
+ pr_debug("%s: ERR HOST_STS2 = %08x\n", \
+ DRIVER_NAME, sh_mmcif_readl(host, MMCIF_CE_HOST_STS2));
+
+ if (state1 & STS1_CMDSEQ) {
+ pr_debug("%s: Forced end of command sequence\n", DRIVER_NAME);
+ sh_mmcif_bitset(host, MMCIF_CE_CMD_CTRL, CMD_CTRL_BREAK);
+ sh_mmcif_bitset(host, MMCIF_CE_CMD_CTRL, ~CMD_CTRL_BREAK);
+ while (1) {
+ timeout--;
+ if (timeout < 0) {
+ pr_err(DRIVER_NAME": Forceed end of " \
+ "command sequence timeout err\n");
+ return -EILSEQ;
+ }
+ if (!(sh_mmcif_readl(host, MMCIF_CE_HOST_STS1)
+ & STS1_CMDSEQ))
+ break;
+ mdelay(1);
+ }
+ sh_mmcif_sync_reset(host);
+ return -EILSEQ;
+ }
+
+ if (state2 & STS2_CRC_ERR)
+ ret = -EILSEQ;
+ else if (state2 & STS2_TIMEOUT_ERR)
+ ret = -ETIMEDOUT;
+ else
+ ret = -EILSEQ;
+ return ret;
+}
+
+static int sh_mmcif_single_read(struct sh_mmcif_host *host,
+ struct mmc_request *mrq)
+{
+ struct mmc_data *data = mrq->data;
+ long time;
+ u32 blocksize, i, *p = sg_virt(data->sg);
+
+ host->wait_int = 0;
+
+ /* buf read enable */
+ sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFREN);
+ time = wait_event_interruptible_timeout(host->intr_wait,
+ host->wait_int == 1 ||
+ host->sd_error == 1, host->timeout);
+ if (host->wait_int != 1 && (time == 0 || host->sd_error != 0))
+ return sh_mmcif_error_manage(host);
+
+ host->wait_int = 0;
+ blocksize = (BLOCK_SIZE_MASK &
+ sh_mmcif_readl(host, MMCIF_CE_BLOCK_SET)) + 3;
+ for (i = 0; i < blocksize / 4; i++)
+ *p++ = sh_mmcif_readl(host, MMCIF_CE_DATA);
+
+ /* buffer read end */
+ sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFRE);
+ time = wait_event_interruptible_timeout(host->intr_wait,
+ host->wait_int == 1 ||
+ host->sd_error == 1, host->timeout);
+ if (host->wait_int != 1 && (time == 0 || host->sd_error != 0))
+ return sh_mmcif_error_manage(host);
+
+ host->wait_int = 0;
+ return 0;
+}
+
+static int sh_mmcif_multi_read(struct sh_mmcif_host *host,
+ struct mmc_request *mrq)
+{
+ struct mmc_data *data = mrq->data;
+ long time;
+ u32 blocksize, i, j, sec, *p;
+
+ blocksize = BLOCK_SIZE_MASK & sh_mmcif_readl(host, MMCIF_CE_BLOCK_SET);
+ for (j = 0; j < data->sg_len; j++) {
+ p = sg_virt(data->sg);
+ host->wait_int = 0;
+ for (sec = 0; sec < data->sg->length / blocksize; sec++) {
+ sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFREN);
+ /* buf read enable */
+ time = wait_event_interruptible_timeout(host->intr_wait,
+ host->wait_int == 1 ||
+ host->sd_error == 1, host->timeout);
+
+ if (host->wait_int != 1 &&
+ (time == 0 || host->sd_error != 0))
+ return sh_mmcif_error_manage(host);
+
+ host->wait_int = 0;
+ for (i = 0; i < blocksize / 4; i++)
+ *p++ = sh_mmcif_readl(host, MMCIF_CE_DATA);
+ }
+ if (j < data->sg_len - 1)
+ data->sg++;
+ }
+ return 0;
+}
+
+static int sh_mmcif_single_write(struct sh_mmcif_host *host,
+ struct mmc_request *mrq)
+{
+ struct mmc_data *data = mrq->data;
+ long time;
+ u32 blocksize, i, *p = sg_virt(data->sg);
+
+ host->wait_int = 0;
+ sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFWEN);
+
+ /* buf write enable */
+ time = wait_event_interruptible_timeout(host->intr_wait,
+ host->wait_int == 1 ||
+ host->sd_error == 1, host->timeout);
+ if (host->wait_int != 1 && (time == 0 || host->sd_error != 0))
+ return sh_mmcif_error_manage(host);
+
+ host->wait_int = 0;
+ blocksize = (BLOCK_SIZE_MASK &
+ sh_mmcif_readl(host, MMCIF_CE_BLOCK_SET)) + 3;
+ for (i = 0; i < blocksize / 4; i++)
+ sh_mmcif_writel(host, MMCIF_CE_DATA, *p++);
+
+ /* buffer write end */
+ sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MDTRANE);
+
+ time = wait_event_interruptible_timeout(host->intr_wait,
+ host->wait_int == 1 ||
+ host->sd_error == 1, host->timeout);
+ if (host->wait_int != 1 && (time == 0 || host->sd_error != 0))
+ return sh_mmcif_error_manage(host);
+
+ host->wait_int = 0;
+ return 0;
+}
+
+static int sh_mmcif_multi_write(struct sh_mmcif_host *host,
+ struct mmc_request *mrq)
+{
+ struct mmc_data *data = mrq->data;
+ long time;
+ u32 i, sec, j, blocksize, *p;
+
+ blocksize = BLOCK_SIZE_MASK & sh_mmcif_readl(host, MMCIF_CE_BLOCK_SET);
+
+ for (j = 0; j < data->sg_len; j++) {
+ p = sg_virt(data->sg);
+ host->wait_int = 0;
+ for (sec = 0; sec < data->sg->length / blocksize; sec++) {
+ sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MBUFWEN);
+ /* buf write enable*/
+ time = wait_event_interruptible_timeout(host->intr_wait,
+ host->wait_int == 1 ||
+ host->sd_error == 1, host->timeout);
+
+ if (host->wait_int != 1 &&
+ (time == 0 || host->sd_error != 0))
+ return sh_mmcif_error_manage(host);
+
+ host->wait_int = 0;
+ for (i = 0; i < blocksize / 4; i++)
+ sh_mmcif_writel(host, MMCIF_CE_DATA, *p++);
+ }
+ if (j < data->sg_len - 1)
+ data->sg++;
+ }
+ return 0;
+}
+
+static void sh_mmcif_get_response(struct sh_mmcif_host *host,
+ struct mmc_command *cmd)
+{
+ if (cmd->flags & MMC_RSP_136) {
+ cmd->resp[0] = sh_mmcif_readl(host, MMCIF_CE_RESP3);
+ cmd->resp[1] = sh_mmcif_readl(host, MMCIF_CE_RESP2);
+ cmd->resp[2] = sh_mmcif_readl(host, MMCIF_CE_RESP1);
+ cmd->resp[3] = sh_mmcif_readl(host, MMCIF_CE_RESP0);
+ } else
+ cmd->resp[0] = sh_mmcif_readl(host, MMCIF_CE_RESP0);
+}
+
+static void sh_mmcif_get_cmd12response(struct sh_mmcif_host *host,
+ struct mmc_command *cmd)
+{
+ cmd->resp[0] = sh_mmcif_readl(host, MMCIF_CE_RESP_CMD12);
+}
+
+static u32 sh_mmcif_set_cmd(struct sh_mmcif_host *host,
+ struct mmc_request *mrq, struct mmc_command *cmd, u32 opc)
+{
+ u32 tmp = 0;
+
+ /* Response Type check */
+ switch (mmc_resp_type(cmd)) {
+ case MMC_RSP_NONE:
+ tmp |= CMD_SET_RTYP_NO;
+ break;
+ case MMC_RSP_R1:
+ case MMC_RSP_R1B:
+ case MMC_RSP_R3:
+ tmp |= CMD_SET_RTYP_6B;
+ break;
+ case MMC_RSP_R2:
+ tmp |= CMD_SET_RTYP_17B;
+ break;
+ default:
+ pr_err(DRIVER_NAME": Not support type response.\n");
+ break;
+ }
+ switch (opc) {
+ /* RBSY */
+ case MMC_SWITCH:
+ case MMC_STOP_TRANSMISSION:
+ case MMC_SET_WRITE_PROT:
+ case MMC_CLR_WRITE_PROT:
+ case MMC_ERASE:
+ case MMC_GEN_CMD:
+ tmp |= CMD_SET_RBSY;
+ break;
+ }
+ /* WDAT / DATW */
+ if (host->data) {
+ tmp |= CMD_SET_WDAT;
+ switch (host->bus_width) {
+ case MMC_BUS_WIDTH_1:
+ tmp |= CMD_SET_DATW_1;
+ break;
+ case MMC_BUS_WIDTH_4:
+ tmp |= CMD_SET_DATW_4;
+ break;
+ case MMC_BUS_WIDTH_8:
+ tmp |= CMD_SET_DATW_8;
+ break;
+ default:
+ pr_err(DRIVER_NAME": Not support bus width.\n");
+ break;
+ }
+ }
+ /* DWEN */
+ if (opc == MMC_WRITE_BLOCK || opc == MMC_WRITE_MULTIPLE_BLOCK)
+ tmp |= CMD_SET_DWEN;
+ /* CMLTE/CMD12EN */
+ if (opc == MMC_READ_MULTIPLE_BLOCK || opc == MMC_WRITE_MULTIPLE_BLOCK) {
+ tmp |= CMD_SET_CMLTE | CMD_SET_CMD12EN;
+ sh_mmcif_bitset(host, MMCIF_CE_BLOCK_SET,
+ mrq->data->blocks << 16);
+ }
+ /* RIDXC[1:0] check bits */
+ if (opc == MMC_SEND_OP_COND || opc == MMC_ALL_SEND_CID ||
+ opc == MMC_SEND_CSD || opc == MMC_SEND_CID)
+ tmp |= CMD_SET_RIDXC_BITS;
+ /* RCRC7C[1:0] check bits */
+ if (opc == MMC_SEND_OP_COND)
+ tmp |= CMD_SET_CRC7C_BITS;
+ /* RCRC7C[1:0] internal CRC7 */
+ if (opc == MMC_ALL_SEND_CID ||
+ opc == MMC_SEND_CSD || opc == MMC_SEND_CID)
+ tmp |= CMD_SET_CRC7C_INTERNAL;
+
+ return opc = ((opc << 24) | tmp);
+}
+
+static u32 sh_mmcif_data_trans(struct sh_mmcif_host *host,
+ struct mmc_request *mrq, u32 opc)
+{
+ u32 ret;
+
+ switch (opc) {
+ case MMC_READ_MULTIPLE_BLOCK:
+ ret = sh_mmcif_multi_read(host, mrq);
+ break;
+ case MMC_WRITE_MULTIPLE_BLOCK:
+ ret = sh_mmcif_multi_write(host, mrq);
+ break;
+ case MMC_WRITE_BLOCK:
+ ret = sh_mmcif_single_write(host, mrq);
+ break;
+ case MMC_READ_SINGLE_BLOCK:
+ case MMC_SEND_EXT_CSD:
+ ret = sh_mmcif_single_read(host, mrq);
+ break;
+ default:
+ pr_err(DRIVER_NAME": NOT SUPPORT CMD = d'%08d\n", opc);
+ ret = -EINVAL;
+ break;
+ }
+ return ret;
+}
+
+static void sh_mmcif_start_cmd(struct sh_mmcif_host *host,
+ struct mmc_request *mrq, struct mmc_command *cmd)
+{
+ long time;
+ int ret = 0, mask = 0;
+ u32 opc = cmd->opcode;
+
+ host->cmd = cmd;
+
+ switch (opc) {
+ /* respons busy check */
+ case MMC_SWITCH:
+ case MMC_STOP_TRANSMISSION:
+ case MMC_SET_WRITE_PROT:
+ case MMC_CLR_WRITE_PROT:
+ case MMC_ERASE:
+ case MMC_GEN_CMD:
+ mask = MASK_MRBSYE;
+ break;
+ default:
+ mask = MASK_MCRSPE;
+ break;
+ }
+ mask |= MASK_MCMDVIO | MASK_MBUFVIO | MASK_MWDATERR |
+ MASK_MRDATERR | MASK_MRIDXERR | MASK_MRSPERR |
+ MASK_MCCSTO | MASK_MCRCSTO | MASK_MWDATTO |
+ MASK_MRDATTO | MASK_MRBSYTO | MASK_MRSPTO;
+
+ if (host->data) {
+ sh_mmcif_writel(host, MMCIF_CE_BLOCK_SET, 0);
+ sh_mmcif_writel(host, MMCIF_CE_BLOCK_SET, mrq->data->blksz);
+ }
+ opc = sh_mmcif_set_cmd(host, mrq, cmd, opc);
+
+ sh_mmcif_writel(host, MMCIF_CE_INT, 0xD80430C0);
+ sh_mmcif_writel(host, MMCIF_CE_INT_MASK, mask);
+ /* set arg */
+ sh_mmcif_writel(host, MMCIF_CE_ARG, cmd->arg);
+ host->wait_int = 0;
+ /* set cmd */
+ sh_mmcif_writel(host, MMCIF_CE_CMD_SET, opc);
+
+ time = wait_event_interruptible_timeout(host->intr_wait,
+ host->wait_int == 1 || host->sd_error == 1, host->timeout);
+ if (host->wait_int != 1 && time == 0) {
+ cmd->error = sh_mmcif_error_manage(host);
+ return;
+ }
+ if (host->sd_error) {
+ switch (cmd->opcode) {
+ case MMC_ALL_SEND_CID:
+ case MMC_SELECT_CARD:
+ case MMC_APP_CMD:
+ cmd->error = -ETIMEDOUT;
+ break;
+ default:
+ pr_debug("%s: Cmd(d'%d) err\n",
+ DRIVER_NAME, cmd->opcode);
+ cmd->error = sh_mmcif_error_manage(host);
+ break;
+ }
+ host->sd_error = 0;
+ host->wait_int = 0;
+ return;
+ }
+ if (!(cmd->flags & MMC_RSP_PRESENT)) {
+ cmd->error = ret;
+ host->wait_int = 0;
+ return;
+ }
+ if (host->wait_int == 1) {
+ sh_mmcif_get_response(host, cmd);
+ host->wait_int = 0;
+ }
+ if (host->data) {
+ ret = sh_mmcif_data_trans(host, mrq, cmd->opcode);
+ if (ret < 0)
+ mrq->data->bytes_xfered = 0;
+ else
+ mrq->data->bytes_xfered =
+ mrq->data->blocks * mrq->data->blksz;
+ }
+ cmd->error = ret;
+}
+
+static void sh_mmcif_stop_cmd(struct sh_mmcif_host *host,
+ struct mmc_request *mrq, struct mmc_command *cmd)
+{
+ long time;
+
+ if (mrq->cmd->opcode == MMC_READ_MULTIPLE_BLOCK)
+ sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MCMD12DRE);
+ else if (mrq->cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK)
+ sh_mmcif_bitset(host, MMCIF_CE_INT_MASK, MASK_MCMD12RBE);
+ else {
+ pr_err(DRIVER_NAME": not support stop cmd\n");
+ cmd->error = sh_mmcif_error_manage(host);
+ return;
+ }
+
+ time = wait_event_interruptible_timeout(host->intr_wait,
+ host->wait_int == 1 ||
+ host->sd_error == 1, host->timeout);
+ if (host->wait_int != 1 && (time == 0 || host->sd_error != 0)) {
+ cmd->error = sh_mmcif_error_manage(host);
+ return;
+ }
+ sh_mmcif_get_cmd12response(host, cmd);
+ host->wait_int = 0;
+ cmd->error = 0;
+}
+
+static void sh_mmcif_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+ struct sh_mmcif_host *host = mmc_priv(mmc);
+
+ switch (mrq->cmd->opcode) {
+ /* MMCIF does not support SD/SDIO command */
+ case SD_IO_SEND_OP_COND:
+ case MMC_APP_CMD:
+ mrq->cmd->error = -ETIMEDOUT;
+ mmc_request_done(mmc, mrq);
+ return;
+ case MMC_SEND_EXT_CSD: /* = SD_SEND_IF_COND (8) */
+ if (!mrq->data) {
+ /* send_if_cond cmd (not support) */
+ mrq->cmd->error = -ETIMEDOUT;
+ mmc_request_done(mmc, mrq);
+ return;
+ }
+ break;
+ default:
+ break;
+ }
+ host->data = mrq->data;
+ sh_mmcif_start_cmd(host, mrq, mrq->cmd);
+ host->data = NULL;
+
+ if (mrq->cmd->error != 0) {
+ mmc_request_done(mmc, mrq);
+ return;
+ }
+ if (mrq->stop)
+ sh_mmcif_stop_cmd(host, mrq, mrq->stop);
+ mmc_request_done(mmc, mrq);
+}
+
+static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+ struct sh_mmcif_host *host = mmc_priv(mmc);
+ struct sh_mmcif_plat_data *p = host->pd->dev.platform_data;
+
+ if (ios->power_mode == MMC_POWER_OFF) {
+ /* clock stop */
+ sh_mmcif_clock_control(host, 0);
+ if (p->down_pwr)
+ p->down_pwr(host->pd);
+ return;
+ } else if (ios->power_mode == MMC_POWER_UP) {
+ if (p->set_pwr)
+ p->set_pwr(host->pd, ios->power_mode);
+ }
+
+ if (ios->clock)
+ sh_mmcif_clock_control(host, ios->clock);
+
+ if (ios->bus_width)
+ host->bus_width = ios->bus_width;
+}
+
+static struct mmc_host_ops sh_mmcif_ops = {
+ .request = sh_mmcif_request,
+ .set_ios = sh_mmcif_set_ios,
+};
+
+static void sh_mmcif_detect(struct mmc_host *mmc)
+{
+ mmc_detect_change(mmc, 0);
+}
+
+static irqreturn_t sh_mmcif_intr(int irq, void *dev_id)
+{
+ struct sh_mmcif_host *host = dev_id;
+ u32 state = 0;
+ int err = 0;
+
+ state = sh_mmcif_readl(host, MMCIF_CE_INT);
+
+ if (state & INT_RBSYE) {
+ sh_mmcif_writel(host, MMCIF_CE_INT, ~(INT_RBSYE | INT_CRSPE));
+ sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, MASK_MRBSYE);
+ } else if (state & INT_CRSPE) {
+ sh_mmcif_writel(host, MMCIF_CE_INT, ~INT_CRSPE);
+ sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, MASK_MCRSPE);
+ } else if (state & INT_BUFREN) {
+ sh_mmcif_writel(host, MMCIF_CE_INT, ~INT_BUFREN);
+ sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, MASK_MBUFREN);
+ } else if (state & INT_BUFWEN) {
+ sh_mmcif_writel(host, MMCIF_CE_INT, ~INT_BUFWEN);
+ sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, MASK_MBUFWEN);
+ } else if (state & INT_CMD12DRE) {
+ sh_mmcif_writel(host, MMCIF_CE_INT,
+ ~(INT_CMD12DRE | INT_CMD12RBE |
+ INT_CMD12CRE | INT_BUFRE));
+ sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, MASK_MCMD12DRE);
+ } else if (state & INT_BUFRE) {
+ sh_mmcif_writel(host, MMCIF_CE_INT, ~INT_BUFRE);
+ sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, MASK_MBUFRE);
+ } else if (state & INT_DTRANE) {
+ sh_mmcif_writel(host, MMCIF_CE_INT, ~INT_DTRANE);
+ sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, MASK_MDTRANE);
+ } else if (state & INT_CMD12RBE) {
+ sh_mmcif_writel(host, MMCIF_CE_INT,
+ ~(INT_CMD12RBE | INT_CMD12CRE));
+ sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, MASK_MCMD12RBE);
+ } else if (state & INT_ERR_STS) {
+ /* err interrupts */
+ sh_mmcif_writel(host, MMCIF_CE_INT, ~state);
+ sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, state);
+ err = 1;
+ } else {
+ pr_debug("%s: Not support int\n", DRIVER_NAME);
+ sh_mmcif_writel(host, MMCIF_CE_INT, ~state);
+ sh_mmcif_bitclr(host, MMCIF_CE_INT_MASK, state);
+ err = 1;
+ }
+ if (err) {
+ host->sd_error = 1;
+ pr_debug("%s: int err state = %08x\n", DRIVER_NAME, state);
+ }
+ host->wait_int = 1;
+ wake_up(&host->intr_wait);
+
+ return IRQ_HANDLED;
+}
+
+static int __devinit sh_mmcif_probe(struct platform_device *pdev)
+{
+ int ret = 0, irq[2];
+ struct mmc_host *mmc;
+ struct sh_mmcif_host *host = NULL;
+ struct sh_mmcif_plat_data *pd = NULL;
+ struct resource *res;
+ void __iomem *reg;
+ char clk_name[8];
+
+ irq[0] = platform_get_irq(pdev, 0);
+ irq[1] = platform_get_irq(pdev, 1);
+ if (irq[0] < 0 || irq[1] < 0) {
+ pr_err(DRIVER_NAME": Get irq error\n");
+ return -ENXIO;
+ }
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "platform_get_resource error.\n");
+ return -ENXIO;
+ }
+ reg = ioremap(res->start, resource_size(res));
+ if (!reg) {
+ dev_err(&pdev->dev, "ioremap error.\n");
+ return -ENOMEM;
+ }
+ pd = (struct sh_mmcif_plat_data *)(pdev->dev.platform_data);
+ if (!pd) {
+ dev_err(&pdev->dev, "sh_mmcif plat data error.\n");
+ ret = -ENXIO;
+ goto clean_up;
+ }
+ mmc = mmc_alloc_host(sizeof(struct sh_mmcif_host), &pdev->dev);
+ if (!mmc) {
+ ret = -ENOMEM;
+ goto clean_up;
+ }
+ host = mmc_priv(mmc);
+ host->mmc = mmc;
+ host->addr = reg;
+ host->timeout = 1000;
+
+ snprintf(clk_name, sizeof(clk_name), "mmc%d", pdev->id);
+ host->hclk = clk_get(&pdev->dev, clk_name);
+ if (IS_ERR(host->hclk)) {
+ dev_err(&pdev->dev, "cannot get clock \"%s\"\n", clk_name);
+ ret = PTR_ERR(host->hclk);
+ goto clean_up1;
+ }
+ clk_enable(host->hclk);
+ host->clk = clk_get_rate(host->hclk);
+ host->pd = pdev;
+
+ init_waitqueue_head(&host->intr_wait);
+
+ mmc->ops = &sh_mmcif_ops;
+ mmc->f_max = host->clk;
+ /* close to 400KHz */
+ if (mmc->f_max < 51200000)
+ mmc->f_min = mmc->f_max / 128;
+ else if (mmc->f_max < 102400000)
+ mmc->f_min = mmc->f_max / 256;
+ else
+ mmc->f_min = mmc->f_max / 512;
+ if (pd->ocr)
+ mmc->ocr_avail = pd->ocr;
+ mmc->caps = MMC_CAP_MMC_HIGHSPEED;
+ if (pd->caps)
+ mmc->caps = pd->caps;
+ mmc->max_phys_segs = 128;
+ mmc->max_hw_segs = 128;
+ mmc->max_blk_size = 512;
+ mmc->max_blk_count = 65535;
+ mmc->max_req_size = mmc->max_blk_size * mmc->max_blk_count;
+ mmc->max_seg_size = mmc->max_req_size;
+
+ sh_mmcif_sync_reset(host);
+ platform_set_drvdata(pdev, host);
+ mmc_add_host(mmc);
+
+ ret = request_irq(irq[0], sh_mmcif_intr, 0, "sh_mmc:error", host);
+ if (ret) {
+ pr_err(DRIVER_NAME": request_irq error (sh_mmc:error)\n");
+ goto clean_up2;
+ }
+ ret = request_irq(irq[1], sh_mmcif_intr, 0, "sh_mmc:int", host);
+ if (ret) {
+ free_irq(irq[0], host);
+ pr_err(DRIVER_NAME": request_irq error (sh_mmc:int)\n");
+ goto clean_up2;
+ }
+
+ sh_mmcif_writel(host, MMCIF_CE_INT_MASK, MASK_ALL);
+ sh_mmcif_detect(host->mmc);
+
+ pr_info("%s: driver version %s\n", DRIVER_NAME, DRIVER_VERSION);
+ pr_debug("%s: chip ver H'%04x\n", DRIVER_NAME,
+ sh_mmcif_readl(host, MMCIF_CE_VERSION) & 0x0000ffff);
+ return ret;
+
+clean_up2:
+ clk_disable(host->hclk);
+clean_up1:
+ mmc_free_host(mmc);
+clean_up:
+ if (reg)
+ iounmap(reg);
+ return ret;
+}
+
+static int __devexit sh_mmcif_remove(struct platform_device *pdev)
+{
+ struct sh_mmcif_host *host = platform_get_drvdata(pdev);
+ int irq[2];
+
+ sh_mmcif_writel(host, MMCIF_CE_INT_MASK, MASK_ALL);
+
+ irq[0] = platform_get_irq(pdev, 0);
+ irq[1] = platform_get_irq(pdev, 1);
+
+ if (host->addr)
+ iounmap(host->addr);
+
+ platform_set_drvdata(pdev, NULL);
+ mmc_remove_host(host->mmc);
+
+ free_irq(irq[0], host);
+ free_irq(irq[1], host);
+
+ clk_disable(host->hclk);
+ mmc_free_host(host->mmc);
+
+ return 0;
+}
+
+static struct platform_driver sh_mmcif_driver = {
+ .probe = sh_mmcif_probe,
+ .remove = sh_mmcif_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ },
+};
+
+static int __init sh_mmcif_init(void)
+{
+ return platform_driver_register(&sh_mmcif_driver);
+}
+
+static void __exit sh_mmcif_exit(void)
+{
+ platform_driver_unregister(&sh_mmcif_driver);
+}
+
+module_init(sh_mmcif_init);
+module_exit(sh_mmcif_exit);
+
+
+MODULE_DESCRIPTION("SuperH on-chip MMC/eMMC interface driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS(DRIVER_NAME);
+MODULE_AUTHOR("Yusuke Goda");
diff --git a/include/linux/mmc/sh_mmcif.h b/include/linux/mmc/sh_mmcif.h
new file mode 100644
index 0000000..aafe832
--- /dev/null
+++ b/include/linux/mmc/sh_mmcif.h
@@ -0,0 +1,39 @@
+/*
+ * include/linux/mmc/sh_mmcif.h
+ *
+ * platform data for eMMC driver
+ *
+ * Copyright (C) 2010 Renesas Solutions Corp.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __SH_MMCIF_H__
+#define __SH_MMCIF_H__
+
+/*
+ * MMCIF : CE_CLK_CTRL [19:16]
+ * 1000 : Peripheral clock / 512
+ * 0111 : Peripheral clock / 256
+ * 0110 : Peripheral clock / 128
+ * 0101 : Peripheral clock / 64
+ * 0100 : Peripheral clock / 32
+ * 0011 : Peripheral clock / 16
+ * 0010 : Peripheral clock / 8
+ * 0001 : Peripheral clock / 4
+ * 0000 : Peripheral clock / 2
+ * 1111 : Peripheral clock (sup_pclk set '1')
+ */
+
+struct sh_mmcif_plat_data {
+ void (*set_pwr)(struct platform_device *pdev, int state);
+ void (*down_pwr)(struct platform_device *pdev);
+ u8 sup_pclk; /* 1 :SH7757, 0: SH7724/SH7372 */
+ unsigned long caps;
+ u32 ocr;
+};
+
+#endif /* __SH_MMCIF_H__ */
--
1.7.0


2010-04-27 22:02:46

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 1/2] MMC: Add support MMCIF for SuperH

On Tue, 27 Apr 2010 19:15:02 +0900
Yusuke Goda <[email protected]> wrote:

>
> MMCIF is MMC Host Interface in SuperH.
>
> ...
>
> +static void sh_mmcif_clock_control(struct sh_mmcif_host *host, unsigned int clk)
> +{
> + int i;
> + struct sh_mmcif_plat_data *p = host->pd->dev.platform_data;
> +
> + sh_mmcif_bitclr(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE);
> + sh_mmcif_bitclr(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR);
> +
> + if (!clk)
> + return;
> + if (p->sup_pclk && clk == host->clk) {
> + sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_SUP_PCLK);
> + } else {
> + for (i = 1; (unsigned int)host->clk / (1 << i) >= clk; i++)
> + ;

I suspect this could be clarified. Perhaps

i = ilog2(__roundup_pow_of_two(host->clk));

If that's wrong then include/linux/log2.h has various tools which can
surely be used. If they're not appropriate then please feel free to
propose additions.

> + sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, (i - 1) << 16);
> + }
> + sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE);
> +}
> +
>
> ...
>
> +static int sh_mmcif_error_manage(struct sh_mmcif_host *host)
> +{
> + u32 state1, state2;
> + int ret, timeout = 10000000;
> +
> + host->sd_error = 0;
> + host->wait_int = 0;
> +
> + state1 = sh_mmcif_readl(host, MMCIF_CE_HOST_STS1);
> + state2 = sh_mmcif_readl(host, MMCIF_CE_HOST_STS2);
> + pr_debug("%s: ERR HOST_STS1 = %08x\n", \
> + DRIVER_NAME, sh_mmcif_readl(host, MMCIF_CE_HOST_STS1));
> + pr_debug("%s: ERR HOST_STS2 = %08x\n", \
> + DRIVER_NAME, sh_mmcif_readl(host, MMCIF_CE_HOST_STS2));
> +
> + if (state1 & STS1_CMDSEQ) {
> + pr_debug("%s: Forced end of command sequence\n", DRIVER_NAME);
> + sh_mmcif_bitset(host, MMCIF_CE_CMD_CTRL, CMD_CTRL_BREAK);
> + sh_mmcif_bitset(host, MMCIF_CE_CMD_CTRL, ~CMD_CTRL_BREAK);
> + while (1) {
> + timeout--;
> + if (timeout < 0) {
> + pr_err(DRIVER_NAME": Forceed end of " \
> + "command sequence timeout err\n");
> + return -EILSEQ;
> + }
> + if (!(sh_mmcif_readl(host, MMCIF_CE_HOST_STS1)
> + & STS1_CMDSEQ))
> + break;
> + mdelay(1);
> + }
> + sh_mmcif_sync_reset(host);
> + return -EILSEQ;

Good heavens, what is EILSEQ?

<googles a bit>

"An illegal multibyte sequence was found in the input. This
usually means that you have the wrong charactor encoding, for
instance the MicrosoftCorporation version of latin-1 (aka
iso_8859_1(7)) (which has it's own stuff like "smart quotes" in
the reserved bytes) instead of the real latin (or perhaps
utf8(7))."

Why on earth are driver writers using this in the kernel??? Imagine
the confusion which ensues when this error code propagates all the way
back to some poor user's console. They'll be scrabbling around with
language encodings not even suspecting that their hardware is busted.

People do this *a lot*. They go grubbing through errno.h and grab
something which looks vaguely appropriate. But it's wrong.

If your hardware is busted then return -EIO and emit a printk to tell
the operator what broke.

> + }
> +
> + if (state2 & STS2_CRC_ERR)
> + ret = -EILSEQ;
> + else if (state2 & STS2_TIMEOUT_ERR)
> + ret = -ETIMEDOUT;
> + else
> + ret = -EILSEQ;
> + return ret;
> +}
>
> ...
>

2010-04-28 04:55:20

by Yusuke Goda

[permalink] [raw]
Subject: Re: [PATCH 1/2] MMC: Add support MMCIF for SuperH

Hi Andrew

Thanks so much for your help.

Andrew Morton wrote:
> On Tue, 27 Apr 2010 19:15:02 +0900
> Yusuke Goda <[email protected]> wrote:
>
>> MMCIF is MMC Host Interface in SuperH.
>>
>> ...
>>
>> +static void sh_mmcif_clock_control(struct sh_mmcif_host *host, unsigned int clk)
>> +{
>> + int i;
>> + struct sh_mmcif_plat_data *p = host->pd->dev.platform_data;
>> +
>> + sh_mmcif_bitclr(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE);
>> + sh_mmcif_bitclr(host, MMCIF_CE_CLK_CTRL, CLK_CLEAR);
>> +
>> + if (!clk)
>> + return;
>> + if (p->sup_pclk && clk == host->clk) {
>> + sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_SUP_PCLK);
>> + } else {
>> + for (i = 1; (unsigned int)host->clk / (1 << i) >= clk; i++)
>> + ;
>
> I suspect this could be clarified. Perhaps
>
> i = ilog2(__roundup_pow_of_two(host->clk));
>
> If that's wrong then include/linux/log2.h has various tools which can
> surely be used. If they're not appropriate then please feel free to
> propose additions.
OK.
I correct it.

>
>> + sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, (i - 1) << 16);
>> + }
>> + sh_mmcif_bitset(host, MMCIF_CE_CLK_CTRL, CLK_ENABLE);
>> +}
>> +
>>
>> ...
>>
>> +static int sh_mmcif_error_manage(struct sh_mmcif_host *host)
>> +{
>> + u32 state1, state2;
>> + int ret, timeout = 10000000;
>> +
>> + host->sd_error = 0;
>> + host->wait_int = 0;
>> +
>> + state1 = sh_mmcif_readl(host, MMCIF_CE_HOST_STS1);
>> + state2 = sh_mmcif_readl(host, MMCIF_CE_HOST_STS2);
>> + pr_debug("%s: ERR HOST_STS1 = %08x\n", \
>> + DRIVER_NAME, sh_mmcif_readl(host, MMCIF_CE_HOST_STS1));
>> + pr_debug("%s: ERR HOST_STS2 = %08x\n", \
>> + DRIVER_NAME, sh_mmcif_readl(host, MMCIF_CE_HOST_STS2));
>> +
>> + if (state1 & STS1_CMDSEQ) {
>> + pr_debug("%s: Forced end of command sequence\n", DRIVER_NAME);
>> + sh_mmcif_bitset(host, MMCIF_CE_CMD_CTRL, CMD_CTRL_BREAK);
>> + sh_mmcif_bitset(host, MMCIF_CE_CMD_CTRL, ~CMD_CTRL_BREAK);
>> + while (1) {
>> + timeout--;
>> + if (timeout < 0) {
>> + pr_err(DRIVER_NAME": Forceed end of " \
>> + "command sequence timeout err\n");
>> + return -EILSEQ;
>> + }
>> + if (!(sh_mmcif_readl(host, MMCIF_CE_HOST_STS1)
>> + & STS1_CMDSEQ))
>> + break;
>> + mdelay(1);
>> + }
>> + sh_mmcif_sync_reset(host);
>> + return -EILSEQ;
>
> Good heavens, what is EILSEQ?
>
> <googles a bit>
>
> "An illegal multibyte sequence was found in the input. This
> usually means that you have the wrong charactor encoding, for
> instance the MicrosoftCorporation version of latin-1 (aka
> iso_8859_1(7)) (which has it's own stuff like "smart quotes" in
> the reserved bytes) instead of the real latin (or perhaps
> utf8(7))."
>
> Why on earth are driver writers using this in the kernel??? Imagine
> the confusion which ensues when this error code propagates all the way
> back to some poor user's console. They'll be scrabbling around with
> language encodings not even suspecting that their hardware is busted.
>
> People do this *a lot*. They go grubbing through errno.h and grab
> something which looks vaguely appropriate. But it's wrong.
>
> If your hardware is busted then return -EIO and emit a printk to tell
> the operator what broke.
>
>> + }
>> +
>> + if (state2 & STS2_CRC_ERR)
>> + ret = -EILSEQ;
>> + else if (state2 & STS2_TIMEOUT_ERR)
>> + ret = -ETIMEDOUT;
>> + else
>> + ret = -EILSEQ;
>> + return ret;
>> +}
Thank you.
I think that EIO is appropriate.

I revise it and send a patch.

Thanks,
Goda