[U-Boot] [PATCH v3 5/5] ARM: dm: spi: Add support DM/DTS for i.MX28 mxs SPI driver (DM_SPI conversion)

Lukasz Majewski
2019-06-15T22:34:42Z

This commit converts mxs_spi driver to support DM/DTS.

Signed-off-by: Lukasz Majewski <lukma@denx.de>

---

Changes in v3:
- Set more apropriate tags

Changes in v2:
- New patch (conversion of mxs_spi.c to DM_SPI)

drivers/spi/mxs_spi.c | 393 +++++++++++++++++++++++++++++++++++++++-----------
1 file changed, 310 insertions(+), 83 deletions(-)

diff --git a/drivers/spi/mxs_spi.c b/drivers/spi/mxs_spi.c
index 5065e407f8..6ae76309d7 100644
--- a/drivers/spi/mxs_spi.c
+++ b/drivers/spi/mxs_spi.c
@@ -2,6 +2,9 @@
/*
* Freescale i.MX28 SPI driver
*
+ * Copyright (C) 2019 DENX Software Engineering
+ * Lukasz Majewski, DENX Software Engineering, lukma at denx.de
+ *
* Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
* on behalf of DENX Software Engineering GmbH
*
@@ -27,6 +30,19 @@

#define MXSSSP_SMALL_TRANSFER 512

+static void mxs_spi_start_xfer(struct mxs_ssp_regs *ssp_regs)
+{
+ writel(SSP_CTRL0_LOCK_CS, &ssp_regs->hw_ssp_ctrl0_set);
+ writel(SSP_CTRL0_IGNORE_CRC, &ssp_regs->hw_ssp_ctrl0_clr);
+}
+
+static void mxs_spi_end_xfer(struct mxs_ssp_regs *ssp_regs)
+{
+ writel(SSP_CTRL0_LOCK_CS, &ssp_regs->hw_ssp_ctrl0_clr);
+ writel(SSP_CTRL0_IGNORE_CRC, &ssp_regs->hw_ssp_ctrl0_set);
+}
+
+#if !CONFIG_IS_ENABLED(DM_SPI)
struct mxs_spi_slave {
struct spi_slave slave;
uint32_t max_khz;
@@ -38,94 +54,38 @@ static inline struct mxs_spi_slave *to_mxs_slave(struct spi_slave *slave)
{
return container_of(slave, struct mxs_spi_slave, slave);
}
+#else
+#include <dm.h>
+#include <errno.h>
+struct mxs_spi_platdata {
+ s32 frequency; /* Default clock frequency, -1 for none */
+ fdt_addr_t base; /* SPI IP block base address */
+ int num_cs; /* Number of CSes supported */
+ int dma_id; /* ID of the DMA channel */
+ int clk_id; /* ID of the SSP clock */
+};

-int spi_cs_is_valid(unsigned int bus, unsigned int cs)
-{
- /* MXS SPI: 4 ports and 3 chip selects maximum */
- if (!mxs_ssp_bus_id_valid(bus) || cs > 2)
- return 0;
- else
- return 1;
-}
-
-struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
- unsigned int max_hz, unsigned int mode)
-{
- struct mxs_spi_slave *mxs_slave;
-
- if (!spi_cs_is_valid(bus, cs)) {
- printf("mxs_spi: invalid bus %d / chip select %d\n", bus, cs);
- return NULL;
- }
-
- mxs_slave = spi_alloc_slave(struct mxs_spi_slave, bus, cs);
- if (!mxs_slave)
- return NULL;
-
- if (mxs_dma_init_channel(MXS_DMA_CHANNEL_AHB_APBH_SSP0 + bus))
- goto err_init;
-
- mxs_slave->max_khz = max_hz / 1000;
- mxs_slave->mode = mode;
- mxs_slave->regs = mxs_ssp_regs_by_bus(bus);
-
- return &mxs_slave->slave;
-
-err_init:
- free(mxs_slave);
- return NULL;
-}
-
-void spi_free_slave(struct spi_slave *slave)
-{
- struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave);
- free(mxs_slave);
-}
-
-int spi_claim_bus(struct spi_slave *slave)
-{
- struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave);
- struct mxs_ssp_regs *ssp_regs = mxs_slave->regs;
- uint32_t reg = 0;
-
- mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
-
- writel((slave->cs << MXS_SSP_CHIPSELECT_SHIFT) |
- SSP_CTRL0_BUS_WIDTH_ONE_BIT,
- &ssp_regs->hw_ssp_ctrl0);
-
- reg = SSP_CTRL1_SSP_MODE_SPI | SSP_CTRL1_WORD_LENGTH_EIGHT_BITS;
- reg |= (mxs_slave->mode & SPI_CPOL) ? SSP_CTRL1_POLARITY : 0;
- reg |= (mxs_slave->mode & SPI_CPHA) ? SSP_CTRL1_PHASE : 0;
- writel(reg, &ssp_regs->hw_ssp_ctrl1);
-
- writel(0, &ssp_regs->hw_ssp_cmd0);
-
- mxs_set_ssp_busclock(slave->bus, mxs_slave->max_khz);
-
- return 0;
-}
-
-void spi_release_bus(struct spi_slave *slave)
-{
-}
-
-static void mxs_spi_start_xfer(struct mxs_ssp_regs *ssp_regs)
-{
- writel(SSP_CTRL0_LOCK_CS, &ssp_regs->hw_ssp_ctrl0_set);
- writel(SSP_CTRL0_IGNORE_CRC, &ssp_regs->hw_ssp_ctrl0_clr);
-}
-
-static void mxs_spi_end_xfer(struct mxs_ssp_regs *ssp_regs)
-{
- writel(SSP_CTRL0_LOCK_CS, &ssp_regs->hw_ssp_ctrl0_clr);
- writel(SSP_CTRL0_IGNORE_CRC, &ssp_regs->hw_ssp_ctrl0_set);
-}
+struct mxs_spi_priv {
+ struct mxs_ssp_regs *regs;
+ unsigned int dma_channel;
+ unsigned int max_freq;
+ unsigned int clk_id;
+ unsigned int mode;
+};
+#endif

+#if !CONFIG_IS_ENABLED(DM_SPI)
static int mxs_spi_xfer_pio(struct mxs_spi_slave *slave,
char *data, int length, int write, unsigned long flags)
{
struct mxs_ssp_regs *ssp_regs = slave->regs;
+#else
+static int mxs_spi_xfer_pio(struct mxs_spi_priv *priv,
+ char *data, int length, int write,
+ unsigned long flags)
+{
+ struct mxs_ssp_regs *ssp_regs = priv->regs;
+#endif

if (flags & SPI_XFER_BEGIN)
mxs_spi_start_xfer(ssp_regs);
@@ -181,12 +141,18 @@ static int mxs_spi_xfer_pio(struct mxs_spi_slave *slave,
return 0;
}

+#if !CONFIG_IS_ENABLED(DM_SPI)
static int mxs_spi_xfer_dma(struct mxs_spi_slave *slave,
char *data, int length, int write, unsigned long flags)
{
+ struct mxs_ssp_regs *ssp_regs = slave->regs;
+#else
+static int mxs_spi_xfer_dma(struct mxs_spi_priv *priv,
+ char *data, int length, int write, unsigned long flags)
+{ struct mxs_ssp_regs *ssp_regs = priv->regs;
+#endif
const int xfer_max_sz = 0xff00;
const int desc_count = DIV_ROUND_UP(length, xfer_max_sz) + 1;
- struct mxs_ssp_regs *ssp_regs = slave->regs;
struct mxs_dma_desc *dp;
uint32_t ctrl0;
uint32_t cache_data_count;
@@ -225,7 +191,11 @@ static int mxs_spi_xfer_dma(struct mxs_spi_slave *slave,
/* Invalidate the area, so no writeback into the RAM races with DMA */
invalidate_dcache_range(dstart, dstart + cache_data_count);

+#if !CONFIG_IS_ENABLED(DM_SPI)
dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + slave->slave.bus;
+#else
+ dmach = priv->dma_channel;
+#endif

dp = desc;
while (length) {
@@ -302,11 +272,20 @@ static int mxs_spi_xfer_dma(struct mxs_spi_slave *slave,
return ret;
}

+#if !CONFIG_IS_ENABLED(DM_SPI)
int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave);
struct mxs_ssp_regs *ssp_regs = mxs_slave->regs;
+#else
+int mxs_spi_xfer(struct udevice *dev, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct udevice *bus = dev_get_parent(dev);
+ struct mxs_spi_priv *priv = dev_get_priv(bus);
+ struct mxs_ssp_regs *ssp_regs = priv->regs;
+#endif
int len = bitlen / 8;
char dummy;
int write = 0;
@@ -350,9 +329,257 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,

if (!dma || (len < MXSSSP_SMALL_TRANSFER)) {
writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_clr);
+#if !CONFIG_IS_ENABLED(DM_SPI)
return mxs_spi_xfer_pio(mxs_slave, data, len, write, flags);
+#else
+ return mxs_spi_xfer_pio(priv, data, len, write, flags);
+#endif
} else {
writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_set);
+#if !CONFIG_IS_ENABLED(DM_SPI)
return mxs_spi_xfer_dma(mxs_slave, data, len, write, flags);
+#else
+ return mxs_spi_xfer_dma(priv, data, len, write, flags);
+#endif
}
}
+
+#if !CONFIG_IS_ENABLED(DM_SPI)
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+ /* MXS SPI: 4 ports and 3 chip selects maximum */
+ if (!mxs_ssp_bus_id_valid(bus) || cs > 2)
+ return 0;
+ else
+ return 1;
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+ unsigned int max_hz, unsigned int mode)
+{
+ struct mxs_spi_slave *mxs_slave;
+
+ if (!spi_cs_is_valid(bus, cs)) {
+ printf("mxs_spi: invalid bus %d / chip select %d\n", bus, cs);
+ return NULL;
+ }
+
+ mxs_slave = spi_alloc_slave(struct mxs_spi_slave, bus, cs);
+ if (!mxs_slave)
+ return NULL;
+
+ if (mxs_dma_init_channel(MXS_DMA_CHANNEL_AHB_APBH_SSP0 + bus))
+ goto err_init;
+
+ mxs_slave->max_khz = max_hz / 1000;
+ mxs_slave->mode = mode;
+ mxs_slave->regs = mxs_ssp_regs_by_bus(bus);
+
+ return &mxs_slave->slave;
+
+err_init:
+ free(mxs_slave);
+ return NULL;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+ struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave);
+ free(mxs_slave);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+ struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave);
+ struct mxs_ssp_regs *ssp_regs = mxs_slave->regs;
+ uint32_t reg = 0;
+
+ mxs_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
+
+ writel((slave->cs << MXS_SSP_CHIPSELECT_SHIFT) |
+ SSP_CTRL0_BUS_WIDTH_ONE_BIT,
+ &ssp_regs->hw_ssp_ctrl0);
+
+ reg = SSP_CTRL1_SSP_MODE_SPI | SSP_CTRL1_WORD_LENGTH_EIGHT_BITS;
+ reg |= (mxs_slave->mode & SPI_CPOL) ? SSP_CTRL1_POLARITY : 0;
+ reg |= (mxs_slave->mode & SPI_CPHA) ? SSP_CTRL1_PHASE : 0;
+ writel(reg, &ssp_regs->hw_ssp_ctrl1);
+
+ writel(0, &ssp_regs->hw_ssp_cmd0);
+
+ mxs_set_ssp_busclock(slave->bus, mxs_slave->max_khz);
+
+ return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+}
+
+#else /* CONFIG_DM_SPI */
+/* Base number of i.MX28 clk for ssp0 IP block */
+#define MXS_SSP_IMX28_CLKID_SSP0 46
+
+static int mxs_spi_probe(struct udevice *bus)
+{
+ struct mxs_spi_platdata *plat = dev_get_platdata(bus);
+ struct mxs_spi_priv *priv = dev_get_priv(bus);
+ int ret;
+
+ debug("%s: probe\n", __func__);
+ priv->regs = (struct mxs_ssp_regs *)plat->base;
+ priv->max_freq = plat->frequency;
+
+ priv->dma_channel = plat->dma_id;
+ priv->clk_id = plat->clk_id;
+
+ ret = mxs_dma_init_channel(priv->dma_channel);
+ if (ret) {
+ printf("%s: DMA init channel error %d\n", __func__, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int mxs_spi_claim_bus(struct udevice *dev)
+{
+ struct udevice *bus = dev_get_parent(dev);
+ struct mxs_spi_priv *priv = dev_get_priv(bus);
+ struct mxs_ssp_regs *ssp_regs = priv->regs;
+ int cs = spi_chip_select(dev);
+
+ /*
+ * i.MX28 supports up to 3 CS (SSn0, SSn1, SSn2)
+ * To set them it uses following tuple (WAIT_FOR_IRQ,WAIT_FOR_CMD),
+ * where:
+ *
+ * WAIT_FOR_IRQ is bit 21 of HW_SSP_CTRL0
+ * WAIT_FOR_CMD is bit 20 (#defined as MXS_SSP_CHIPSELECT_SHIFT here) of
+ * HW_SSP_CTRL0
+ * SSn0 b00
+ * SSn1 b01
+ * SSn2 b10 (which require setting WAIT_FOR_IRQ)
+ *
+ * However, for now i.MX28 SPI driver will support up till 2 CSes
+ * (SSn0, and SSn1).
+ */
+
+ /* Ungate SSP clock and set active CS */
+ clrsetbits_le32(&ssp_regs->hw_ssp_ctrl0,
+ (1 << MXS_SSP_CHIPSELECT_SHIFT) |
+ SSP_CTRL0_CLKGATE, (cs << MXS_SSP_CHIPSELECT_SHIFT));
+
+ return 0;
+}
+
+static int mxs_spi_release_bus(struct udevice *dev)
+{
+ struct udevice *bus = dev_get_parent(dev);
+ struct mxs_spi_priv *priv = dev_get_priv(bus);
+ struct mxs_ssp_regs *ssp_regs = priv->regs;
+
+ /* Gate SSP clock */
+ setbits_le32(&ssp_regs->hw_ssp_ctrl0, SSP_CTRL0_CLKGATE);
+
+ return 0;
+}
+
+static int mxs_spi_set_speed(struct udevice *bus, uint speed)
+{
+ struct mxs_spi_priv *priv = dev_get_priv(bus);
+ int clkid = priv->clk_id - MXS_SSP_IMX28_CLKID_SSP0;
+
+ if (speed > priv->max_freq)
+ speed = priv->max_freq;
+
+ debug("%s speed: %u [Hz] clkid: %d\n", __func__, speed, clkid);
+ mxs_set_ssp_busclock(clkid, speed / 1000);
+
+ return 0;
+}
+
+static int mxs_spi_set_mode(struct udevice *bus, uint mode)
+{
+ struct mxs_spi_priv *priv = dev_get_priv(bus);
+ struct mxs_ssp_regs *ssp_regs = priv->regs;
+ u32 reg;
+
+ priv->mode = mode;
+ debug("%s: mode 0x%x\n", __func__, mode);
+
+ reg = SSP_CTRL1_SSP_MODE_SPI | SSP_CTRL1_WORD_LENGTH_EIGHT_BITS;
+ reg |= (priv->mode & SPI_CPOL) ? SSP_CTRL1_POLARITY : 0;
+ reg |= (priv->mode & SPI_CPHA) ? SSP_CTRL1_PHASE : 0;
+ writel(reg, &ssp_regs->hw_ssp_ctrl1);
+
+ /* Single bit SPI support */
+ writel(SSP_CTRL0_BUS_WIDTH_ONE_BIT, &ssp_regs->hw_ssp_ctrl0);
+
+ return 0;
+}
+
+static const struct dm_spi_ops mxs_spi_ops = {
+ .claim_bus = mxs_spi_claim_bus,
+ .release_bus = mxs_spi_release_bus,
+ .xfer = mxs_spi_xfer,
+ .set_speed = mxs_spi_set_speed,
+ .set_mode = mxs_spi_set_mode,
+ /*
+ * cs_info is not needed, since we require all chip selects to be
+ * in the device tree explicitly
+ */
+};
+
+#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
+static int mxs_ofdata_to_platdata(struct udevice *bus)
+{
+ struct mxs_spi_platdata *plat = bus->platdata;
+ u32 prop[2];
+ int ret;
+
+ plat->base = dev_read_addr(bus);
+ plat->frequency =
+ dev_read_u32_default(bus, "spi-max-frequency", 40000000);
+ plat->num_cs = dev_read_u32_default(bus, "num-cs", 2);
+
+ ret = dev_read_u32_array(bus, "dmas", prop, ARRAY_SIZE(prop));
+ if (ret) {
+ printf("%s: Reading 'dmas' property failed!\n", __func__);
+ return ret;
+ }
+ plat->dma_id = prop[1];
+
+ ret = dev_read_u32_array(bus, "clocks", prop, ARRAY_SIZE(prop));
+ if (ret) {
+ printf("%s: Reading 'clocks' property failed!\n", __func__);
+ return ret;
+ }
+ plat->clk_id = prop[1];
+
+ debug("%s: base=0x%x, max-frequency=%d num-cs=%d dma_id=%d clk_id=%d\n",
+ __func__, (uint)plat->base, plat->frequency, plat->num_cs,
+ plat->dma_id, plat->clk_id);
+
+ return 0;
+}
+#endif
+
+static const struct udevice_id mxs_spi_ids[] = {
+ { .compatible = "fsl,imx28-spi" },
+ { }
+};
+
+U_BOOT_DRIVER(mxs_spi) = {
+ .name = "mxs_spi",
+ .id = UCLASS_SPI,
+#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
+ .of_match = mxs_spi_ids,
+ .ofdata_to_platdata = mxs_ofdata_to_platdata,
+#endif
+ .priv_auto_alloc_size = sizeof(struct mxs_spi_platdata),
+ .ops = &mxs_spi_ops,
+ .priv_auto_alloc_size = sizeof(struct mxs_spi_priv),
+ .probe = mxs_spi_probe,
+};
+#endif
--
2.11.0