Re: [PATCH v5 4/5] mmc: sdhci-tegra: Implement alternative_gpt_sector()

Tegra20/30/114/124 Android devices place GPT at a non-standard location.
Implement alternative_gpt_sector() callback of the MMC host ops which
specifies that GPT location for the partition scanner.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 drivers/mmc/host/sdhci-tegra.c | 42 ++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 387ce9cdbd7c..24a713689d5b 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c

@@ -116,6 +116,8 @@
  */
 #define NVQUIRK_HAS_TMCLK                              BIT(10)

+#define NVQUIRK_HAS_ANDROID_GPT_SECTOR                 BIT(11)
+
 /* SDMMC CQE Base Address for Tegra Host Ver 4.1 and Higher */
 #define SDHCI_TEGRA_CQE_BASE_ADDR                      0xF000

@@ -1361,6 +1363,7 @@ static const struct sdhci_tegra_soc_data soc_data_tegra20 = {
        .pdata = &sdhci_tegra20_pdata,
        .dma_mask = DMA_BIT_MASK(32),
        .nvquirks = NVQUIRK_FORCE_SDHCI_SPEC_200 |
+                   NVQUIRK_HAS_ANDROID_GPT_SECTOR |
                    NVQUIRK_ENABLE_BLOCK_GAP_DET,
 };

@@ -1390,6 +1393,7 @@ static const struct sdhci_tegra_soc_data soc_data_tegra30 = {
        .nvquirks = NVQUIRK_ENABLE_SDHCI_SPEC_300 |
                    NVQUIRK_ENABLE_SDR50 |
                    NVQUIRK_ENABLE_SDR104 |
+                   NVQUIRK_HAS_ANDROID_GPT_SECTOR |
                    NVQUIRK_HAS_PADCALIB,
 };

@@ -1422,6 +1426,7 @@ static const struct sdhci_pltfm_data sdhci_tegra114_pdata = {
 static const struct sdhci_tegra_soc_data soc_data_tegra114 = {
        .pdata = &sdhci_tegra114_pdata,
        .dma_mask = DMA_BIT_MASK(32),
+       .nvquirks = NVQUIRK_HAS_ANDROID_GPT_SECTOR,
 };

 static const struct sdhci_pltfm_data sdhci_tegra124_pdata = {

@@ -1438,6 +1443,7 @@ static const struct sdhci_pltfm_data sdhci_tegra124_pdata = {
 static const struct sdhci_tegra_soc_data soc_data_tegra124 = {
        .pdata = &sdhci_tegra124_pdata,
        .dma_mask = DMA_BIT_MASK(34),
+       .nvquirks = NVQUIRK_HAS_ANDROID_GPT_SECTOR,
 };

 static const struct sdhci_ops tegra210_sdhci_ops = {

@@ -1590,6 +1596,38 @@ static int sdhci_tegra_add_host(struct sdhci_host *host)
        return ret;
 }

+static int sdhci_tegra_alternative_gpt_sector(struct mmc_card *card,
+                                             sector_t *gpt_sector)
+{
+       unsigned int boot_sectors_num;
+
+       /* filter out unrelated cards */
+       if (card->ext_csd.rev < 3 ||
+           !mmc_card_mmc(card) ||
+           !mmc_card_is_blockaddr(card) ||
+            mmc_card_is_removable(card->host))
+               return -ENOENT;
+
+       /*
+        * eMMC storage has two special boot partitions in addition to the
+        * main one.  NVIDIA's bootloader linearizes eMMC boot0->boot1->main
+        * accesses, this means that the partition table addresses are shifted
+        * by the size of boot partitions.  In accordance with the eMMC
+        * specification, the boot partition size is calculated as follows:
+        *
+        *      boot partition size = 128K byte x BOOT_SIZE_MULT
+        *
+        * Calculate number of sectors occupied by the both boot partitions.
+        */
+       boot_sectors_num = card->ext_csd.raw_boot_mult * SZ_128K /
+                          SZ_512 * MMC_NUM_BOOT_PARTITION;
+
+       /* Defined by NVIDIA and used by Android devices. */
+       *gpt_sector = card->ext_csd.sectors - boot_sectors_num - 1;
+
+       return 0;
+}

+
 static int sdhci_tegra_probe(struct platform_device *pdev)
 {
        const struct of_device_id *match;

@@ -1616,6 +1654,10 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
        tegra_host->pad_control_available = false;
        tegra_host->soc_data = soc_data;

+       if (soc_data->nvquirks & NVQUIRK_HAS_ANDROID_GPT_SECTOR)
+               host->mmc_host_ops.alternative_gpt_sector =
+                               sdhci_tegra_alternative_gpt_sector;
+
        if (soc_data->nvquirks & NVQUIRK_NEEDS_PAD_CONTROL) {
                rc = tegra_sdhci_init_pinctrl_info(&pdev->dev, tegra_host);
                if (rc == 0)
--

2.32.0