Re: [PATCH v5 3/3] mmc: host: add Coldfire esdhc support

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Hi Adrian and all,

thanks,

i can fix also these small issues in a v6 in case. Since is "acked" not sure
if i have to do it. Please let me know.

Also, checkpatch signals a missing maintainer name for this driver,
if there is any need to set a name for it ?

Regards,
Angelo

On Sat, May 16, 2020 at 8:09 PM Adrian Hunter <adrian.hunter@xxxxxxxxx> wrote:

On 16/05/20 1:27 am, Angelo Dureghello wrote:
This driver has been developed as a separate module starting
from the similar sdhci-esdhc-imx.c.

Reasons for a separate sdchi-esdhc-mcf driver:

- m68K architecture does not support devicetrees, so modifying
sdhci-of-esdhc.c that is devicetree-related adding platform data
seems not appropriate,
- clock-related part, has to be implemented specifically for
mcf5441x family (see esdhc_mcf_pltfm_set_clock()),
- this is a big endian cpu accessing a big endian controller,
but about sdma, this controller does not support hw swap, which
needs to be handled with specific code,
- some other minor differences but mainly to avoid risks on
tweaking inside largely used imx driver. Adding just a small
size ColdFire-specific driver, with benefits in a further less
risky maintenance.

Signed-off-by: Angelo Dureghello <angelo.dureghello@xxxxxxxxxxx>

One minor comment below, nevertheless:

Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>

---
Changes for v3:
- fix write support
Changes for v4:
none
Changes for v5:
- better probe cleanup on errors
- test for bounce buffer to be allocated
- rename pre_dma_transfer to copy_to_bounce_buffer
- change swap to swap and copy to bounce buffer
- fix line alignments to pass checkpatch --strict
---
 drivers/mmc/host/Kconfig           |  13 +
 drivers/mmc/host/Makefile          |   1 +
 drivers/mmc/host/sdhci-esdhc-mcf.c | 522 +++++++++++++++++++++++++++++
 3 files changed, 536 insertions(+)
 create mode 100644 drivers/mmc/host/sdhci-esdhc-mcf.c

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 462b5352fea7..da793fc95203 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -235,6 +235,19 @@ config MMC_SDHCI_CNS3XXX

        If unsure, say N.

+config MMC_SDHCI_ESDHC_MCF
+     tristate "SDHCI support for the Freescale eSDHC ColdFire controller"
+     depends on M5441x
+     depends on MMC_SDHCI_PLTFM
+     select MMC_SDHCI_IO_ACCESSORS
+     help
+       This selects the Freescale eSDHC controller support for
+       ColdFire mcf5441x devices.
+
+       If you have a controller with this interface, say Y or M here.
+
+       If unsure, say N.
+
 config MMC_SDHCI_ESDHC_IMX
      tristate "SDHCI support for the Freescale eSDHC/uSDHC i.MX controller"
      depends on ARCH_MXC
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index b929ef941208..af2cdaadc4d3 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -82,6 +82,7 @@ obj-$(CONFIG_MMC_REALTEK_USB)       += rtsx_usb_sdmmc.o
 obj-$(CONFIG_MMC_SDHCI_PLTFM)                += sdhci-pltfm.o
 obj-$(CONFIG_MMC_SDHCI_CADENCE)              += sdhci-cadence.o
 obj-$(CONFIG_MMC_SDHCI_CNS3XXX)              += sdhci-cns3xxx.o
+obj-$(CONFIG_MMC_SDHCI_ESDHC_MCF)       += sdhci-esdhc-mcf.o
 obj-$(CONFIG_MMC_SDHCI_ESDHC_IMX)    += sdhci-esdhc-imx.o
 obj-$(CONFIG_MMC_SDHCI_DOVE)         += sdhci-dove.o
 obj-$(CONFIG_MMC_SDHCI_TEGRA)                += sdhci-tegra.o
diff --git a/drivers/mmc/host/sdhci-esdhc-mcf.c b/drivers/mmc/host/sdhci-esdhc-mcf.c
new file mode 100644
index 000000000000..445faf76e676
--- /dev/null
+++ b/drivers/mmc/host/sdhci-esdhc-mcf.c
@@ -0,0 +1,522 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Freescale eSDHC ColdFire family controller driver, platform bus.
+ *
+ * Copyright (c) 2020 Timesys Corporation
+ *   Author: Angelo Dureghello <angelo.dureghello@xxxxxxxxxx>
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/platform_data/mmc-esdhc-mcf.h>
+#include <linux/mmc/mmc.h>
+#include "sdhci-pltfm.h"
+#include "sdhci-esdhc.h"
+
+#define      ESDHC_PROCTL_D3CD               0x08
+#define ESDHC_SYS_CTRL_DTOCV_MASK    0x0f
+#define ESDHC_DEFAULT_HOST_CONTROL   0x28
+
+/*
+ * Freescale eSDHC has DMA ERR flag at bit 28, not as std spec says, bit 25.
+ */
+#define ESDHC_INT_VENDOR_SPEC_DMA_ERR        BIT(28)
+
+struct pltfm_mcf_data {
+     struct clk *clk_ipg;
+     struct clk *clk_ahb;
+     struct clk *clk_per;
+     int aside;
+     int current_bus_width;
+};
+
+static inline void esdhc_mcf_buffer_swap32(u32 *buf, int len)
+{
+     int i;
+     u32 temp;
+
+     len = (len + 3) >> 2;
+
+     for (i = 0; i < len;  i++) {
+             temp = swab32(*buf);
+             *buf++ = temp;
+     }
+}
+
+static inline void esdhc_clrset_be(struct sdhci_host *host,
+                                u32 mask, u32 val, int reg)
+{
+     void __iomem *base = host->ioaddr + (reg & ~3);
+     u8 shift = (reg & 3) << 3;
+
+     mask <<= shift;
+     val <<= shift;
+
+     if (reg == SDHCI_HOST_CONTROL)
+             val |= ESDHC_PROCTL_D3CD;
+
+     writel((readl(base) & ~mask) | val, base);
+}
+
+/*
+ * Note: mcf is big-endian, single bytes need to be accessed at big endian
+ * offsets.
+ */
+static void esdhc_mcf_writeb_be(struct sdhci_host *host, u8 val, int reg)
+{
+     void __iomem *base = host->ioaddr + (reg & ~3);
+     u8 shift = (reg & 3) << 3;
+     u32 mask = ~(0xff << shift);
+
+     if (reg == SDHCI_HOST_CONTROL) {
+             u32 host_ctrl = ESDHC_DEFAULT_HOST_CONTROL;
+             u8 dma_bits = (val & SDHCI_CTRL_DMA_MASK) >> 3;
+             u8 tmp = readb(host->ioaddr + SDHCI_HOST_CONTROL + 1);
+
+             tmp &= ~0x03;
+             tmp |= dma_bits;
+
+             /*
+              * Recomposition needed, restore always endianness and
+              * keep D3CD and AI, just setting bus width.
+              */
+             host_ctrl |= val;
+             host_ctrl |= (dma_bits << 8);
+             writel(host_ctrl, host->ioaddr + SDHCI_HOST_CONTROL);
+
+             return;
+     }
+
+     writel((readl(base) & mask) | (val << shift), base);
+}
+
+static void esdhc_mcf_writew_be(struct sdhci_host *host, u16 val, int reg)
+{
+     struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+     struct pltfm_mcf_data *mcf_data = sdhci_pltfm_priv(pltfm_host);
+     void __iomem *base = host->ioaddr + (reg & ~3);
+     u8 shift = (reg & 3) << 3;
+     u32 mask = ~(0xffff << shift);
+
+     switch (reg) {
+     case SDHCI_TRANSFER_MODE:
+             mcf_data->aside = val;
+             return;
+     case SDHCI_COMMAND:
+             if (host->cmd->opcode == MMC_STOP_TRANSMISSION)
+                     val |= SDHCI_CMD_ABORTCMD;
+
+             /*
+              * As for the fsl driver,
+              * we have to set the mode in a single write here.
+              */
+             writel(val << 16 | mcf_data->aside,
+                    host->ioaddr + SDHCI_TRANSFER_MODE);
+             return;
+     }
+
+     writel((readl(base) & mask) | (val << shift), base);
+}
+
+static void esdhc_mcf_writel_be(struct sdhci_host *host, u32 val, int reg)
+{
+     writel(val, host->ioaddr + reg);
+}
+
+static u8 esdhc_mcf_readb_be(struct sdhci_host *host, int reg)
+{
+     if (reg == SDHCI_HOST_CONTROL) {
+             u8 __iomem *base = host->ioaddr + (reg & ~3);
+             u16 val = readw(base + 2);
+             u8 dma_bits = (val >> 5) & SDHCI_CTRL_DMA_MASK;
+             u8 host_ctrl = val & 0xff;
+
+             host_ctrl &= ~SDHCI_CTRL_DMA_MASK;
+             host_ctrl |= dma_bits;
+
+             return host_ctrl;
+     }
+
+     return readb(host->ioaddr + (reg ^ 0x3));
+}
+
+static u16 esdhc_mcf_readw_be(struct sdhci_host *host, int reg)
+{
+     /*
+      * For SDHCI_HOST_VERSION, sdhci specs defines 0xFE,
+      * a wrong offset for us, we are at 0xFC.
+      */
+     if (reg == SDHCI_HOST_VERSION)
+             reg -= 2;
+
+     return readw(host->ioaddr + (reg ^ 0x2));
+}
+
+static u32 esdhc_mcf_readl_be(struct sdhci_host *host, int reg)
+{
+     u32 val;
+
+     val = readl(host->ioaddr + reg);
+
+     /*
+      * RM (25.3.9) sd pin clock must never exceed 25Mhz.
+      * So forcing legacy mode at 25Mhz.
+      */
+     if (unlikely(reg == SDHCI_CAPABILITIES))
+             val &= ~SDHCI_CAN_DO_HISPD;
+
+     if (unlikely(reg == SDHCI_INT_STATUS)) {
+             if (val & ESDHC_INT_VENDOR_SPEC_DMA_ERR) {
+                     val &= ~ESDHC_INT_VENDOR_SPEC_DMA_ERR;
+                     val |= SDHCI_INT_ADMA_ERROR;
+             }
+     }
+
+     return val;
+}
+
+static unsigned int esdhc_mcf_get_max_timeout_count(struct sdhci_host *host)
+{
+     return 1 << 27;
+}
+
+static void esdhc_mcf_set_timeout(struct sdhci_host *host,
+                               struct mmc_command *cmd)
+{
+     /* Use maximum timeout counter */
+     esdhc_clrset_be(host, ESDHC_SYS_CTRL_DTOCV_MASK, 0xE,
+                     SDHCI_TIMEOUT_CONTROL);
+}
+
+static void esdhc_mcf_reset(struct sdhci_host *host, u8 mask)
+{
+     struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+     struct pltfm_mcf_data *mcf_data = sdhci_pltfm_priv(pltfm_host);
+
+     sdhci_reset(host, mask);
+
+     esdhc_clrset_be(host, ESDHC_CTRL_BUSWIDTH_MASK,
+                     mcf_data->current_bus_width, SDHCI_HOST_CONTROL);
+
+     sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
+     sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
+}
+
+static unsigned int esdhc_mcf_pltfm_get_max_clock(struct sdhci_host *host)
+{
+     struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+     return pltfm_host->clock;
+}
+
+static unsigned int esdhc_mcf_pltfm_get_min_clock(struct sdhci_host *host)
+{
+     struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+
+     return pltfm_host->clock / 256 / 16;
+}
+
+static void esdhc_mcf_pltfm_set_clock(struct sdhci_host *host,
+                                   unsigned int clock)
+{
+     struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+     unsigned long *pll_dr = (unsigned long *)MCF_PLL_DR;
+     u32 fvco, fsys, fesdhc, temp;
+     const int sdclkfs[] = {2, 4, 8, 16, 32, 64, 128, 256};
+     int delta, old_delta = clock;
+     int i, q, ri, rq;
+
+     if (clock == 0) {
+             host->mmc->actual_clock = 0;
+             return;
+     }
+
+     /*
+      * ColdFire eSDHC clock.s
+      *
+      * pll -+-> / outdiv1 --> fsys
+      *      +-> / outdiv3 --> eSDHC clock ---> / SDCCLKFS / DVS
+      *
+      * mcf5441x datasheet says:
+      * (8.1.2) eSDHC should be 40 MHz max
+      * (25.3.9) eSDHC input is, as example, 96 Mhz ...
+      * (25.3.9) sd pin clock must never exceed 25Mhz
+      *
+      * fvco = fsys * outdvi1 + 1
+      * fshdc = fvco / outdiv3 + 1
+      */
+     temp = readl(pll_dr);
+     fsys = pltfm_host->clock;
+     fvco = fsys * ((temp & 0x1f) + 1);
+     fesdhc = fvco / (((temp >> 10) & 0x1f) + 1);
+
+     for (i = 0; i < 8; ++i) {
+             int result = fesdhc / sdclkfs[i];
+
+             for (q = 1; q < 17; ++q) {
+                     int finale = result / q;
+
+                     delta = abs(clock - finale);
+
+                     if (delta < old_delta) {
+                             old_delta = delta;
+                             ri = i;
+                             rq = q;
+                     }
+             }
+     }
+
+     /*
+      * Apply divisors and re-enable all the clocks
+      */
+     temp = ((sdclkfs[ri] >> 1) << 8) | ((rq - 1) << 4) |
+             (ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN);
+     esdhc_clrset_be(host, 0x0000fff7, temp, SDHCI_CLOCK_CONTROL);
+
+     host->mmc->actual_clock = clock;
+
+     mdelay(1);
+}
+
+static void esdhc_mcf_pltfm_set_bus_width(struct sdhci_host *host, int width)
+{
+     struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+     struct pltfm_mcf_data *mcf_data = sdhci_pltfm_priv(pltfm_host);
+
+     switch (width) {
+     case MMC_BUS_WIDTH_4:
+             mcf_data->current_bus_width = ESDHC_CTRL_4BITBUS;
+             break;
+     default:
+             mcf_data->current_bus_width = 0;
+             break;
+     }
+
+     esdhc_clrset_be(host, ESDHC_CTRL_BUSWIDTH_MASK,
+                     mcf_data->current_bus_width, SDHCI_HOST_CONTROL);
+}
+
+static void esdhc_mcf_request_done(struct sdhci_host *host,
+                                struct mmc_request *mrq)
+{
+     struct scatterlist *sg;
+     u32 *buffer;
+     int i;
+
+     if (!mrq->data || !mrq->data->bytes_xfered)
+             goto exit_done;
+
+     if (mmc_get_dma_dir(mrq->data) != DMA_FROM_DEVICE)
+             goto exit_done;
+
+     /*
+      * On mcf5441x there is no hw sdma option/flag to select the dma
+      * transfer endiannes. A swap after the transfer is needed.
+      */
+     for_each_sg(mrq->data->sg, sg, mrq->data->sg_len, i) {
+             buffer = (u32 *)sg_virt(sg);
+             esdhc_mcf_buffer_swap32(buffer, sg->length);
+     }
+
+exit_done:
+     mmc_request_done(host->mmc, mrq);
+}
+
+static void esdhc_mcf_copy_to_bounce_buffer(struct sdhci_host *host,
+                                         struct mmc_data *data)
+{
+     unsigned int length = data->blksz * data->blocks;
+
+     sg_copy_to_buffer(data->sg, data->sg_len,
+                       host->bounce_buffer, length);
+
+     esdhc_mcf_buffer_swap32((u32 *)host->bounce_buffer,
+                             data->blksz * data->blocks);

data->blksz * data->blocks is already calculated as 'length'

+}
+
+static struct sdhci_ops sdhci_esdhc_ops = {
+     .reset = esdhc_mcf_reset,
+     .set_clock = esdhc_mcf_pltfm_set_clock,
+     .get_max_clock = esdhc_mcf_pltfm_get_max_clock,
+     .get_min_clock = esdhc_mcf_pltfm_get_min_clock,
+     .set_bus_width = esdhc_mcf_pltfm_set_bus_width,
+     .get_max_timeout_count = esdhc_mcf_get_max_timeout_count,
+     .set_timeout = esdhc_mcf_set_timeout,
+     .write_b = esdhc_mcf_writeb_be,
+     .write_w = esdhc_mcf_writew_be,
+     .write_l = esdhc_mcf_writel_be,
+     .read_b = esdhc_mcf_readb_be,
+     .read_w = esdhc_mcf_readw_be,
+     .read_l = esdhc_mcf_readl_be,
+     .copy_to_bounce_buffer = esdhc_mcf_copy_to_bounce_buffer,
+     .request_done = esdhc_mcf_request_done,
+};
+
+static const struct sdhci_pltfm_data sdhci_esdhc_mcf_pdata = {
+     .ops = &sdhci_esdhc_ops,
+     .quirks = ESDHC_DEFAULT_QUIRKS | SDHCI_QUIRK_FORCE_DMA,
+              /*
+               * Mandatory quirk,
+               * controller does not support cmd23,
+               * without, on > 8G cards cmd23 is used, and
+               * driver times out.
+               */
+               SDHCI_QUIRK2_HOST_NO_CMD23,
+};
+
+static int esdhc_mcf_plat_init(struct sdhci_host *host,
+                            struct pltfm_mcf_data *mcf_data)
+{
+     struct mcf_esdhc_platform_data *plat_data;
+
+     if (!host->mmc->parent->platform_data) {
+             dev_err(mmc_dev(host->mmc), "no platform data!\n");
+             return -EINVAL;
+     }
+
+     plat_data = (struct mcf_esdhc_platform_data *)
+                     host->mmc->parent->platform_data;
+
+     /* Card_detect */
+     switch (plat_data->cd_type) {
+     default:
+     case ESDHC_CD_CONTROLLER:
+             /* We have a working card_detect back */
+             host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
+             break;
+     case ESDHC_CD_PERMANENT:
+             host->mmc->caps |= MMC_CAP_NONREMOVABLE;
+             break;
+     case ESDHC_CD_NONE:
+             break;
+     }
+
+     switch (plat_data->max_bus_width) {
+     case 4:
+             host->mmc->caps |= MMC_CAP_4_BIT_DATA;
+             break;
+     case 1:
+     default:
+             host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA;
+             break;
+     }
+
+     return 0;
+}
+
+static int sdhci_esdhc_mcf_probe(struct platform_device *pdev)
+{
+     struct sdhci_host *host;
+     struct sdhci_pltfm_host *pltfm_host;
+     struct pltfm_mcf_data *mcf_data;
+     int err;
+
+     host = sdhci_pltfm_init(pdev, &sdhci_esdhc_mcf_pdata,
+                             sizeof(*mcf_data));
+
+     if (IS_ERR(host))
+             return PTR_ERR(host);
+
+     pltfm_host = sdhci_priv(host);
+     mcf_data = sdhci_pltfm_priv(pltfm_host);
+
+     host->sdma_boundary = 0;
+
+     host->flags |= SDHCI_AUTO_CMD12;
+
+     mcf_data->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+     if (IS_ERR(mcf_data->clk_ipg)) {
+             err = PTR_ERR(mcf_data->clk_ipg);
+             goto err_exit;
+     }
+
+     mcf_data->clk_ahb = devm_clk_get(&pdev->dev, "ahb");
+     if (IS_ERR(mcf_data->clk_ahb)) {
+             err = PTR_ERR(mcf_data->clk_ahb);
+             goto err_exit;
+     }
+
+     mcf_data->clk_per = devm_clk_get(&pdev->dev, "per");
+     if (IS_ERR(mcf_data->clk_per)) {
+             err = PTR_ERR(mcf_data->clk_per);
+             goto err_exit;
+     }
+
+     pltfm_host->clk = mcf_data->clk_per;
+     pltfm_host->clock = clk_get_rate(pltfm_host->clk);
+     err = clk_prepare_enable(mcf_data->clk_per);
+     if (err)
+             goto err_exit;
+
+     err = clk_prepare_enable(mcf_data->clk_ipg);
+     if (err)
+             goto unprep_per;
+
+     err = clk_prepare_enable(mcf_data->clk_ahb);
+     if (err)
+             goto unprep_ipg;
+
+     err = esdhc_mcf_plat_init(host, mcf_data);
+     if (err)
+             goto unprep_ahb;
+
+     err = sdhci_setup_host(host);
+     if (err)
+             goto unprep_ahb;
+
+     if (!host->bounce_buffer) {
+             dev_err(&pdev->dev, "bounce buffer not allocated");
+             err = -ENOMEM;
+             goto cleanup;
+     }
+
+     err = __sdhci_add_host(host);
+     if (err)
+             goto cleanup;
+
+     return 0;
+
+cleanup:
+     sdhci_cleanup_host(host);
+unprep_ahb:
+     clk_disable_unprepare(mcf_data->clk_ahb);
+unprep_ipg:
+     clk_disable_unprepare(mcf_data->clk_ipg);
+unprep_per:
+     clk_disable_unprepare(mcf_data->clk_per);
+err_exit:
+     sdhci_pltfm_free(pdev);
+
+     return err;
+}
+
+static int sdhci_esdhc_mcf_remove(struct platform_device *pdev)
+{
+     struct sdhci_host *host = platform_get_drvdata(pdev);
+     struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+     struct pltfm_mcf_data *mcf_data = sdhci_pltfm_priv(pltfm_host);
+
+     sdhci_remove_host(host, 0);
+
+     clk_disable_unprepare(mcf_data->clk_ipg);
+     clk_disable_unprepare(mcf_data->clk_ahb);
+     clk_disable_unprepare(mcf_data->clk_per);
+
+     sdhci_pltfm_free(pdev);
+
+     return 0;
+}
+
+static struct platform_driver sdhci_esdhc_mcf_driver = {
+     .driver = {
+             .name = "sdhci-esdhc-mcf",
+     },
+     .probe = sdhci_esdhc_mcf_probe,
+     .remove = sdhci_esdhc_mcf_remove,
+};
+
+module_platform_driver(sdhci_esdhc_mcf_driver);
+
+MODULE_DESCRIPTION("SDHCI driver for Freescale ColdFire eSDHC");
+MODULE_AUTHOR("Angelo Dureghello <angelo.dureghello@xxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");




-- 
Angelo Dureghello
Timesys
e. angelo.dureghello@xxxxxxxxxxx



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