mxs: mmc: spi: dma: Better wrap the MXS differences

This patch streamlines the differences between the MX23 and MX28 by
implementing a few helper functions to handle different DMA channel
mapping, different clock domain for SSP block and fixes a few minor
bugs.

First of all, the DMA channel mapping is now fixed in dma.h by defining
the actual channel map for both MX23 and MX28. Thus, MX23 now does no
longer use MX28 channel map which was wrong. Also, there is a fix for
MX28 DMA channel map, where the last four channels were incorrect.

Next, because correct DMA channel map is in place, the mxs_dma_init_channel()
call now bases the channel ID starting from SSP port #0. This removes the
need for DMA channel offset being added and cleans up the code. For the
same reason, the SSP0 offset can now be used in mxs_dma_desc_append(), thus
no need to adjust dma channel number in the driver either.

Lastly, the SSP clock ID is now retrieved by calling mxs_ssp_clock_by_bus()
which handles the fact that MX23 has shared SSP clock for both ports, while
MX28 has per-port SSP clock.

Finally, the mxs_ssp_bus_id_valid() pulls out two implementations of the
same functionality from MMC and SPI driver into common code.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Otavio Salvador <otavio@ossystems.com.br>
Cc: Stefano Babic <sbabic@denx.de>

3 files changed, 46 insertions, 2 deletions

diff --git a/arch/arm/cpu/arm926ejs/mxs/clock.c b/arch/arm/cpu/arm926ejs/mxs/clock.c
index 00b9aba..43e7663 100644
--- a/arch/arm/cpu/arm926ejs/mxs/clock.c
+++ b/arch/arm/cpu/arm926ejs/mxs/clock.c
@@ -289,7 +289,8 @@ static uint32_t mxs_get_sspclk(enum mxs_sspclock ssp)
 void mxs_set_ssp_busclock(unsigned int bus, uint32_t freq)
 {
 	struct mxs_ssp_regs *ssp_regs;
-	const uint32_t sspclk = mxs_get_sspclk(bus);
+	const enum mxs_sspclock clk = mxs_ssp_clock_by_bus(bus);
+	const uint32_t sspclk = mxs_get_sspclk(clk);
 	uint32_t reg;
 	uint32_t divide, rate, tgtclk;
 
diff --git a/arch/arm/include/asm/arch-mxs/dma.h b/arch/arm/include/asm/arch-mxs/dma.h
index a0a0ea5..1ac8696 100644
--- a/arch/arm/include/asm/arch-mxs/dma.h
+++ b/arch/arm/include/asm/arch-mxs/dma.h
@@ -40,6 +40,19 @@
 /*
  * MXS DMA channels
  */
+#if defined(CONFIG_MX23)
+enum {
+	MXS_DMA_CHANNEL_AHB_APBH_LCDIF = 0,
+	MXS_DMA_CHANNEL_AHB_APBH_SSP0,
+	MXS_DMA_CHANNEL_AHB_APBH_SSP1,
+	MXS_DMA_CHANNEL_AHB_APBH_RESERVED0,
+	MXS_DMA_CHANNEL_AHB_APBH_GPMI0,
+	MXS_DMA_CHANNEL_AHB_APBH_GPMI1,
+	MXS_DMA_CHANNEL_AHB_APBH_GPMI2,
+	MXS_DMA_CHANNEL_AHB_APBH_GPMI3,
+	MXS_MAX_DMA_CHANNELS,
+};
+#elif defined(CONFIG_MX28)
 enum {
 	MXS_DMA_CHANNEL_AHB_APBH_SSP0 = 0,
 	MXS_DMA_CHANNEL_AHB_APBH_SSP1,
@@ -53,9 +66,13 @@ enum {
 	MXS_DMA_CHANNEL_AHB_APBH_GPMI5,
 	MXS_DMA_CHANNEL_AHB_APBH_GPMI6,
 	MXS_DMA_CHANNEL_AHB_APBH_GPMI7,
-	MXS_DMA_CHANNEL_AHB_APBH_SSP,
+	MXS_DMA_CHANNEL_AHB_APBH_HSADC,
+	MXS_DMA_CHANNEL_AHB_APBH_LCDIF,
+	MXS_DMA_CHANNEL_AHB_APBH_RESERVED0,
+	MXS_DMA_CHANNEL_AHB_APBH_RESERVED1,
 	MXS_MAX_DMA_CHANNELS,
 };
+#endif
 
 /*
  * MXS DMA hardware command.
diff --git a/arch/arm/include/asm/arch-mxs/regs-ssp.h b/arch/arm/include/asm/arch-mxs/regs-ssp.h
index 9b30f56..5920f9b 100644
--- a/arch/arm/include/asm/arch-mxs/regs-ssp.h
+++ b/arch/arm/include/asm/arch-mxs/regs-ssp.h
@@ -74,6 +74,32 @@ struct mxs_ssp_regs {
 };
 #endif
 
+static inline int mxs_ssp_bus_id_valid(int bus)
+{
+#if defined(CONFIG_MX23)
+	const unsigned int mxs_ssp_chan_count = 2;
+#elif defined(CONFIG_MX28)
+	const unsigned int mxs_ssp_chan_count = 4;
+#endif
+
+	if (bus >= mxs_ssp_chan_count)
+		return 0;
+
+	if (bus < 0)
+		return 0;
+
+	return 1;
+}
+
+static inline int mxs_ssp_clock_by_bus(unsigned int clock)
+{
+#if defined(CONFIG_MX23)
+	return 0;
+#elif defined(CONFIG_MX28)
+	return clock;
+#endif
+}
+
 static inline struct mxs_ssp_regs *mxs_ssp_regs_by_bus(unsigned int port)
 {
 	switch (port) {