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From:   Harish Jenny K N <harish_kandiga@mentor.com>
To:     <ulf.hansson@linaro.org>, <linus.walleij@linaro.org>,
        <adrian.hunter@intel.com>, <shawn.lin@rock-chips.com>,
        <avri.altman@wdc.com>, <andriy.shevchenko@linux.intel.com>
CC:     <linux-mmc@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <harish_kandiga@mentor.com>, <Vladimir_Zapolskiy@mentor.com>
Subject: [PATCH v7] mmc: Export host capabilities to debugfs.
Date:   Wed, 7 Mar 2018 18:11:02 +0530
Message-ID: <1520426462-3039-1-git-send-email-harish_kandiga@mentor.com>
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Sender: linux-kernel-owner@vger.kernel.org
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This patch exports the host capabilities to debugfs

This idea of sharing host capabilities over debugfs
came up from Abbas Raza <Abbas_Raza@mentor.com>
Earlier discussions:
https://lkml.org/lkml/2018/3/5/357
https://www.spinics.net/lists/linux-mmc/msg48219.html

Signed-off-by: Harish Jenny K N <harish_kandiga@mentor.com>
---

Changes in v7
- Moved additional capabilities also to caps file as mentioned by Ulf Hansson
- compacting the code with macros

Changes in v6:
- Used DEFINE_SHOW_ATTRIBUTE

Changes in v5:
- Added parser logic in kernel by using debugfs_create_file  for caps and caps2 instead of debugfs_create_x32
- Changed Author

Changes in v4:
- Moved the creation of nodes to mmc_add_host_debugfs
- Exported caps2
- Renamed host_caps to caps

Changes in v3:
- Removed typecasting of &host->caps to (u32 *)

Changes in v2:
- Changed Author

 drivers/mmc/core/debugfs.c | 114 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 114 insertions(+)

diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index c51e0c0..f2fbeae 100644
--- a/drivers/mmc/core/debugfs.c
+++ b/drivers/mmc/core/debugfs.c
@@ -225,6 +225,117 @@ static int mmc_clock_opt_set(void *data, u64 val)
 DEFINE_SIMPLE_ATTRIBUTE(mmc_clock_fops, mmc_clock_opt_get, mmc_clock_opt_set,
 	"%llu\n");

+static int mmc_caps_show(struct seq_file *s, void *unused)
+{
+#define YN(bit) ((caps & bit) ? "Yes" : "No")
+#define YN2(bit) ((caps2 & bit) ? "Yes" : "No")
+	struct mmc_host *host = s->private;
+	u32 caps = host->caps;
+	u32 caps2 = host->caps2;
+
+	seq_puts(s, "\nMMC Host capabilities are:\n");
+	seq_puts(s, "=============================================\n");
+	seq_printf(s, "Can the host do 4 bit transfers :\t%s\n",
+		   YN(MMC_CAP_4_BIT_DATA));
+	seq_printf(s, "Can do MMC high-speed timing :\t%s\n",
+		   YN(MMC_CAP_MMC_HIGHSPEED));
+	seq_printf(s, "Can do SD high-speed timing :\t%s\n",
+		   YN(MMC_CAP_SD_HIGHSPEED));
+	seq_printf(s, "Can signal pending SDIO IRQs :\t%s\n",
+		   YN(MMC_CAP_SDIO_IRQ));
+	seq_printf(s, "Talks only SPI protocols :\t%s\n",
+		   YN(MMC_CAP_SPI));
+	seq_printf(s, "Needs polling for card-detection :\t%s\n",
+		   YN(MMC_CAP_NEEDS_POLL));
+	seq_printf(s, "Can the host do 8 bit transfers :\t%s\n",
+		   YN(MMC_CAP_8_BIT_DATA));
+	seq_printf(s, "Suspend (e)MMC/SD at idle :\t%s\n",
+		   YN(MMC_CAP_AGGRESSIVE_PM));
+	seq_printf(s, "Nonremovable e.g. eMMC :\t%s\n",
+		   YN(MMC_CAP_NONREMOVABLE));
+	seq_printf(s, "Waits while card is busy :\t%s\n",
+		   YN(MMC_CAP_WAIT_WHILE_BUSY));
+	seq_printf(s, "Allow erase/trim commands :\t%s\n",
+		   YN(MMC_CAP_ERASE));
+	seq_printf(s, "Can support DDR mode at 3.3V :\t%s\n",
+		   YN(MMC_CAP_3_3V_DDR));
+	seq_printf(s, "Can support DDR mode at 1.8V :\t%s\n",
+		   YN(MMC_CAP_1_8V_DDR));
+	seq_printf(s, "Can support DDR mode at 1.2V :\t%s\n",
+		   YN(MMC_CAP_1_2V_DDR));
+	seq_printf(s, "Can power off after boot :\t%s\n",
+		   YN(MMC_CAP_POWER_OFF_CARD));
+	seq_printf(s, "CMD14/CMD19 bus width ok :\t%s\n",
+		   YN(MMC_CAP_BUS_WIDTH_TEST));
+	seq_printf(s, "Host supports UHS SDR12 mode :\t%s\n",
+		   YN(MMC_CAP_UHS_SDR12));
+	seq_printf(s, "Host supports UHS SDR25 mode :\t%s\n",
+		   YN(MMC_CAP_UHS_SDR25));
+	seq_printf(s, "Host supports UHS SDR50 mode :\t%s\n",
+		   YN(MMC_CAP_UHS_SDR50));
+	seq_printf(s, "Host supports UHS SDR104 mode :\t%s\n",
+		   YN(MMC_CAP_UHS_SDR104));
+	seq_printf(s, "Host supports UHS DDR50 mode :\t%s\n",
+		   YN(MMC_CAP_UHS_DDR50));
+	seq_printf(s, "Host supports Driver Type A :\t%s\n",
+		   YN(MMC_CAP_DRIVER_TYPE_A));
+	seq_printf(s, "Host supports Driver Type C :\t%s\n",
+		   YN(MMC_CAP_DRIVER_TYPE_C));
+	seq_printf(s, "Host supports Driver Type D :\t%s\n",
+		   YN(MMC_CAP_DRIVER_TYPE_D));
+	seq_printf(s, "RW reqs can be completed within mmc_request_done() :\t%s\n",
+		   YN(MMC_CAP_DONE_COMPLETE));
+	seq_printf(s, "Enable card detect wake :\t%s\n",
+		   YN(MMC_CAP_CD_WAKE));
+	seq_printf(s, "Commands during data transfer :\t%s\n",
+		   YN(MMC_CAP_CMD_DURING_TFR));
+	seq_printf(s, "CMD23 supported. :\t%s\n",
+		   YN(MMC_CAP_CMD23));
+	seq_printf(s, "Hardware reset :\t%s\n",
+		   YN(MMC_CAP_HW_RESET));
+	seq_puts(s, "=============================================\n");
+	seq_puts(s, "MMC Host additional capabilities are:\n");
+	seq_puts(s, "=============================================\n");
+	seq_printf(s, "Boot partition no access :\t%s\n",
+		   YN2(MMC_CAP2_BOOTPART_NOACC));
+	seq_printf(s, "Can do full power cycle :\t%s\n",
+		   YN2(MMC_CAP2_FULL_PWR_CYCLE));
+	seq_printf(s, "Can support HS200 1.8V SDR :\t%s\n",
+		   YN2(MMC_CAP2_HS200_1_8V_SDR));
+	seq_printf(s, "Can support HS200 1.2V SDR :\t%s\n",
+		   YN2(MMC_CAP2_HS200_1_2V_SDR));
+	seq_printf(s, "Card-detect signal active high :\t%s\n",
+		   YN2(MMC_CAP2_CD_ACTIVE_HIGH));
+	seq_printf(s, "Write-protect signal active high :\t%s\n",
+		   YN2(MMC_CAP2_RO_ACTIVE_HIGH));
+	seq_printf(s, "Don't power up before scan :\t%s\n",
+		   YN2(MMC_CAP2_NO_PRESCAN_POWERUP));
+	seq_printf(s, "Can support HS400 1.8V :\t%s\n",
+		   YN2(MMC_CAP2_HS400_1_8V));
+	seq_printf(s, "Can support HS400 1.2V :\t%s\n",
+		   YN2(MMC_CAP2_HS400_1_2V));
+	seq_printf(s, "SDIO IRQ Nothread :\t%s\n",
+		   YN2(MMC_CAP2_SDIO_IRQ_NOTHREAD));
+	seq_printf(s, "No physical write protect pin, assume always read-write :\t%s\n",
+		   YN2(MMC_CAP2_NO_WRITE_PROTECT));
+	seq_printf(s, "Do not send SDIO commands during initialization :\t%s\n",
+		   YN2(MMC_CAP2_NO_SDIO));
+	seq_printf(s, "Host supports enhanced strobe :\t%s\n",
+		   YN2(MMC_CAP2_HS400_ES));
+	seq_printf(s, "Do not send SD commands during initialization :\t%s\n",
+		   YN2(MMC_CAP2_NO_SD));
+	seq_printf(s, "Do not send (e)MMC commands during initialization :\t%s\n",
+		   YN2(MMC_CAP2_NO_MMC));
+	seq_printf(s, "Has eMMC command queue engine :\t%s\n",
+		   YN2(MMC_CAP2_CQE));
+	seq_printf(s, "CQE can issue a direct command :\t%s\n",
+		   YN2(MMC_CAP2_CQE_DCMD));
+	return 0;
+#undef YN
+#undef YN2
+}
+DEFINE_SHOW_ATTRIBUTE(mmc_caps);
+
 void mmc_add_host_debugfs(struct mmc_host *host)
 {
 	struct dentry *root;
@@ -243,6 +354,9 @@ void mmc_add_host_debugfs(struct mmc_host *host)
 	if (!debugfs_create_file("ios", S_IRUSR, root, host, &mmc_ios_fops))
 		goto err_node;

+	if (!debugfs_create_file("caps", S_IRUSR, root, host, &mmc_caps_fops))
+		goto err_node;
+
 	if (!debugfs_create_file("clock", S_IRUSR | S_IWUSR, root, host,
 			&mmc_clock_fops))
 		goto err_node;
--
1.9.1