mmc: Improve tinification

Drop all the extra content from the MMC core, so that tiny MMC support
is really tiny, no fancy anything. That means the tiny MMC support does
only 1-bit transfers at default speed settings. Moreover, this patch
drops duplicate instance of struct mmc mmc_static, which wasted about
360 bytes. Furthermore, since MMC tiny supports only one controller
at all times, get rid of mallocating the ext csd backup and replace
it with static array. All in all, this patch saves ~4 kiB of bloat
from the MMC core, which on platforms with severe limitations can be
beneficial.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
[trini: Fixup checkpatch.pl style warnings]
Signed-off-by: Tom Rini <trini@konsulko.com>

drivers/mmc/mmc.c

@@ -23,29 +23,8 @@
 
 static int mmc_set_signal_voltage(struct mmc *mmc, uint signal_voltage);
 static int mmc_power_cycle(struct mmc *mmc);
+#if !CONFIG_IS_ENABLED(MMC_TINY)
 static int mmc_select_mode_and_width(struct mmc *mmc, uint card_caps);
-
-#if CONFIG_IS_ENABLED(MMC_TINY)
-static struct mmc mmc_static;
-struct mmc *find_mmc_device(int dev_num)
-{
-	return &mmc_static;
-}
-
-void mmc_do_preinit(void)
-{
-	struct mmc *m = &mmc_static;
-#ifdef CONFIG_FSL_ESDHC_ADAPTER_IDENT
-	mmc_set_preinit(m, 1);
-#endif
-	if (m->preinit)
-		mmc_start_init(m);
-}
-
-struct blk_desc *mmc_get_blk_desc(struct mmc *mmc)
-{
-	return &mmc->block_dev;
-}
 #endif
 
 #if !CONFIG_IS_ENABLED(DM_MMC)
@@ -772,6 +751,7 @@ int mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value)
 
 }
 
+#if !CONFIG_IS_ENABLED(MMC_TINY)
 static int mmc_set_card_speed(struct mmc *mmc, enum bus_mode mode)
 {
 	int err;
@@ -855,6 +835,7 @@ static int mmc_get_capabilities(struct mmc *mmc)
 
 	return 0;
 }
+#endif
 
 static int mmc_set_capacity(struct mmc *mmc, int part_num)
 {
@@ -1154,6 +1135,7 @@ int mmc_getcd(struct mmc *mmc)
 }
 #endif
 
+#if !CONFIG_IS_ENABLED(MMC_TINY)
 static int sd_switch(struct mmc *mmc, int mode, int group, u8 value, u8 *resp)
 {
 	struct mmc_cmd cmd;
@@ -1174,7 +1156,6 @@ static int sd_switch(struct mmc *mmc, int mode, int group, u8 value, u8 *resp)
 	return mmc_send_cmd(mmc, &cmd, &data);
 }
 
-
 static int sd_get_capabilities(struct mmc *mmc)
 {
 	int err;
@@ -1361,6 +1342,7 @@ static int sd_select_bus_width(struct mmc *mmc, int w)
 
 	return 0;
 }
+#endif
 
 #if CONFIG_IS_ENABLED(MMC_WRITE)
 static int sd_read_ssr(struct mmc *mmc)
@@ -1584,6 +1566,7 @@ static inline int mmc_set_signal_voltage(struct mmc *mmc, uint signal_voltage)
 }
 #endif
 
+#if !CONFIG_IS_ENABLED(MMC_TINY)
 static const struct mode_width_tuning sd_modes_by_pref[] = {
 #if CONFIG_IS_ENABLED(MMC_UHS_SUPPORT)
 #ifdef MMC_SUPPORTS_TUNING
@@ -1936,6 +1919,11 @@ error:
 
 	return -ENOTSUPP;
 }
+#endif
+
+#if CONFIG_IS_ENABLED(MMC_TINY)
+DEFINE_CACHE_ALIGN_BUFFER(u8, ext_csd_bkup, MMC_MAX_BLOCK_LEN);
+#endif
 
 static int mmc_startup_v4(struct mmc *mmc)
 {
@@ -1955,6 +1943,23 @@ static int mmc_startup_v4(struct mmc *mmc)
 		MMC_VERSION_5_1
 	};
 
+#if CONFIG_IS_ENABLED(MMC_TINY)
+	u8 *ext_csd = ext_csd_bkup;
+
+	if (IS_SD(mmc) || mmc->version < MMC_VERSION_4)
+		return 0;
+
+	if (!mmc->ext_csd)
+		memset(ext_csd_bkup, 0, sizeof(ext_csd_bkup));
+
+	err = mmc_send_ext_csd(mmc, ext_csd);
+	if (err)
+		goto error;
+
+	/* store the ext csd for future reference */
+	if (!mmc->ext_csd)
+		mmc->ext_csd = ext_csd;
+#else
 	ALLOC_CACHE_ALIGN_BUFFER(u8, ext_csd, MMC_MAX_BLOCK_LEN);
 
 	if (IS_SD(mmc) || (mmc->version < MMC_VERSION_4))
@@ -1971,7 +1976,7 @@ static int mmc_startup_v4(struct mmc *mmc)
 	if (!mmc->ext_csd)
 		return -ENOMEM;
 	memcpy(mmc->ext_csd, ext_csd, MMC_MAX_BLOCK_LEN);
-
+#endif
 	if (ext_csd[EXT_CSD_REV] >= ARRAY_SIZE(mmc_versions))
 		return -EINVAL;
 
@@ -2110,7 +2115,9 @@ static int mmc_startup_v4(struct mmc *mmc)
 	return 0;
 error:
 	if (mmc->ext_csd) {
+#if !CONFIG_IS_ENABLED(MMC_TINY)
 		free(mmc->ext_csd);
+#endif
 		mmc->ext_csd = NULL;
 	}
 	return err;
@@ -2299,6 +2306,11 @@ static int mmc_startup(struct mmc *mmc)
 	if (err)
 		return err;
 
+#if CONFIG_IS_ENABLED(MMC_TINY)
+	mmc_set_clock(mmc, mmc->legacy_speed, false);
+	mmc_select_mode(mmc, IS_SD(mmc) ? SD_LEGACY : MMC_LEGACY);
+	mmc_set_bus_width(mmc, 1);
+#else
 	if (IS_SD(mmc)) {
 		err = sd_get_capabilities(mmc);
 		if (err)
@@ -2310,7 +2322,7 @@ static int mmc_startup(struct mmc *mmc)
 			return err;
 		mmc_select_mode_and_width(mmc, mmc->card_caps);
 	}
-
+#endif
 	if (err)
 		return err;
 

drivers/mmc/mmc_legacy.c

@@ -12,7 +12,28 @@
 static struct list_head mmc_devices;
 static int cur_dev_num = -1;
 
-#if !CONFIG_IS_ENABLED(MMC_TINY)
+#if CONFIG_IS_ENABLED(MMC_TINY)
+static struct mmc mmc_static;
+struct mmc *find_mmc_device(int dev_num)
+{
+	return &mmc_static;
+}
+
+void mmc_do_preinit(void)
+{
+	struct mmc *m = &mmc_static;
+#ifdef CONFIG_FSL_ESDHC_ADAPTER_IDENT
+	mmc_set_preinit(m, 1);
+#endif
+	if (m->preinit)
+		mmc_start_init(m);
+}
+
+struct blk_desc *mmc_get_blk_desc(struct mmc *mmc)
+{
+	return &mmc->block_dev;
+}
+#else
 struct mmc *find_mmc_device(int dev_num)
 {
 	struct mmc *m;