[U-Boot] [PATCH v3] drivers: spi: migrate cf_spi to DM

26 Jun 2018

This patch adds DM support to cf_spi.c.
How to use/test it:
1) enable the following options,
CONFIG_DM_SPI
CONFIG_DM_SPI_FLASH
2) add similar code into your board.c file
U_BOOT_DEVICE(coldfire_spi) = {
    .name = "spi_coldfire",
    .platdata = &mcf_spi_plat,
};
---
Changes from v1:
- split into 2 patches
Changes from v2:
- back in a single patch, no need to add fdt support or special
  config options
- doc/driver-model/spi-howto.txt has been re-checked and followed,
  the driver now builds as is.
Signed-off-by: Angelo Dureghello angelo@sysam.it
---
 drivers/spi/cf_spi.c                    | 421 +++++++++++++++---------
 include/dm/platform_data/spi_coldfire.h |  22 ++
 2 files changed, 293 insertions(+), 150 deletions(-)
 create mode 100644 include/dm/platform_data/spi_coldfire.h

diff --git a/drivers/spi/cf_spi.c b/drivers/spi/cf_spi.c
index 522631cbbf..7627f70a1f 100644
--- a/drivers/spi/cf_spi.c
+++ b/drivers/spi/cf_spi.c
@@ -6,15 +6,24 @@
  *
  * Copyright (C) 2004-2009 Freescale Semiconductor, Inc.
  * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
+ *
+ * Support for device model:
+ * Copyright (C) 2018 Angelo Dureghello angelo@sysam.it
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
  */
#include <common.h>
+#include <dm.h>
+#include <dm/platform_data/spi_coldfire.h>
 #include <spi.h>
 #include <malloc.h>
 #include <asm/immap.h>
-struct cf_spi_slave {
+struct coldfire_spi_priv {
+#ifndef CONFIG_DM_SPI
    struct spi_slave slave;
+#endif
    uint baudrate;
    int charbit;
 };
@@ -38,12 +47,7 @@ DECLARE_GLOBAL_DATA_PTR;
 #define SPI_MODE_MOD	0x00200000
 #define SPI_DBLRATE	0x00100000
-static inline struct cf_spi_slave *to_cf_spi_slave(struct spi_slave *slave)
-{
-	return container_of(slave, struct cf_spi_slave, slave);
-}
-
-static void cfspi_init(void)
+static void __spi_init(void)
 {
    volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
@@ -81,7 +85,123 @@ static void cfspi_init(void)
 #endif
 }
-static void cfspi_tx(u32 ctrl, u16 data)
+int __spi_set_speed(struct coldfire_spi_priv *cfspi, uint bus, uint mode)
+{
+	/*
+	 * bit definition for mode:
+	 * bit 31 - 28: Transfer size 3 to 16 bits
+	 *     27 - 26: PCS to SCK delay prescaler
+	 *     25 - 24: After SCK delay prescaler
+	 *     23 - 22: Delay after transfer prescaler
+	 *     21     : Allow overwrite for bit 31-22 and bit 20-8
+	 *     20     : Double baud rate
+	 *     19 - 16: PCS to SCK delay scaler
+	 *     15 - 12: After SCK delay scaler
+	 *     11 -  8: Delay after transfer scaler
+	 *      7 -  0: SPI_CPHA, SPI_CPOL, SPI_LSB_FIRST
+	 */
+	volatile dspi_t *dspi = (dspi_t *)MMAP_DSPI;
+	int prescaler[] = { 2, 3, 5, 7 };
+	int scaler[] = {
+		2, 4, 6, 8,
+		16, 32, 64, 128,
+		256, 512, 1024, 2048,
+		4096, 8192, 16384, 32768
+	};
+	int i, j, pbrcnt, brcnt, diff, tmp, dbr = 0;
+	int best_i, best_j, bestmatch = 0x7FFFFFFF, baud_speed;
+	u32 bus_setup = 0;
+
+	tmp = (prescaler[3] * scaler[15]);
+	/* Maximum and minimum baudrate it can handle */
+	if ((cfspi->baudrate > (gd->bus_clk >> 1)) ||
+	    (cfspi->baudrate < (gd->bus_clk / tmp))) {
+		printf("Exceed baudrate limitation: Max %d - Min %d\n",
+		       (int)(gd->bus_clk >> 1), (int)(gd->bus_clk / tmp));
+		return -1;
+	}
+
+	/* Activate Double Baud when it exceed 1/4 the bus clk */
+	if ((CONFIG_SYS_DSPI_CTAR0 & DSPI_CTAR_DBR) ||
+	    (cfspi->baudrate > (gd->bus_clk / (prescaler[0] * scaler[0])))) {
+		bus_setup |= DSPI_CTAR_DBR;
+		dbr = 1;
+	}
+
+	/* Overwrite default value set in platform configuration file */
+	if (mode & SPI_MODE_MOD) {
+		/*
+		 * Check to see if it is enabled by default in platform
+		 * config, or manual setting passed by mode parameter
+		 */
+		if (mode & SPI_DBLRATE) {
+			bus_setup |= DSPI_CTAR_DBR;
+			dbr = 1;
+		}
+	}
+
+	pbrcnt = sizeof(prescaler) / sizeof(int);
+	brcnt = sizeof(scaler) / sizeof(int);
+
+	/* baudrate calculation - to closer value, may not be exact match */
+	for (best_i = 0, best_j = 0, i = 0; i < pbrcnt; i++) {
+		baud_speed = gd->bus_clk / prescaler[i];
+		for (j = 0; j < brcnt; j++) {
+			tmp = (baud_speed / scaler[j]) * (1 + dbr);
+
+			if (tmp > cfspi->baudrate)
+				diff = tmp - cfspi->baudrate;
+			else
+				diff = cfspi->baudrate - tmp;
+
+			if (diff < bestmatch) {
+				bestmatch = diff;
+				best_i = i;
+				best_j = j;
+			}
+		}
+	}
+	bus_setup |= (DSPI_CTAR_PBR(best_i) | DSPI_CTAR_BR(best_j));
+	dspi->ctar[bus] |= bus_setup;
+
+	return 0;
+}
+
+static int __spi_set_mode(struct coldfire_spi_priv *cfspi, uint bus, uint mode)
+{
+	volatile dspi_t *dspi = (dspi_t *)MMAP_DSPI;
+	u32 bus_setup = 0;
+
+	if (mode & SPI_CPOL)
+		bus_setup |= DSPI_CTAR_CPOL;
+	if (mode & SPI_CPHA)
+		bus_setup |= DSPI_CTAR_CPHA;
+	if (mode & SPI_LSB_FIRST)
+		bus_setup |= DSPI_CTAR_LSBFE;
+
+	/* Overwrite default value set in platform configuration file */
+	if (mode & SPI_MODE_MOD) {
+		if ((mode & 0xF0000000) == 0)
+			bus_setup |=
+			    dspi->ctar[bus] & 0x78000000;
+		else
+			bus_setup |= ((mode & 0xF0000000) >> 1);
+
+		bus_setup |= (mode & 0x0FC00000) >> 4;	/* PSCSCK, PASC, PDT */
+		bus_setup |= (mode & 0x000FFF00) >> 4;	/* CSSCK, ASC, DT */
+	} else {
+		bus_setup |= (dspi->ctar[bus] & 0x78FCFFF0);
+	}
+
+	cfspi->charbit =
+		((dspi->ctar[bus] & 0x78000000) == 0x78000000) ? 16 : 8;
+
+	dspi->ctar[bus] |= bus_setup;
+
+	return 0;
+}
+
+static void __cfspi_tx(u32 ctrl, u16 data)
 {
    volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
@@ -90,7 +210,7 @@ static void cfspi_tx(u32 ctrl, u16 data)
    dspi->tfr = (ctrl | data);
 }
-static u16 cfspi_rx(void)
+static u16 __cfspi_rx(void)
 {
    volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
@@ -99,16 +219,15 @@ static u16 cfspi_rx(void)
    return (dspi->rfr & 0xFFFF);
 }
-static int cfspi_xfer(struct spi_slave *slave, uint bitlen, const void *dout,
-		      void *din, ulong flags)
+static int __spi_xfer(struct coldfire_spi_priv *cfspi, uint cs, uint bitlen,
+		      const void *dout, void *din, ulong flags)
 {
-	struct cf_spi_slave *cfslave = to_cf_spi_slave(slave);
    u16 *spi_rd16 = NULL, *spi_wr16 = NULL;
    u8 *spi_rd = NULL, *spi_wr = NULL;
    static u32 ctrl = 0;
    uint len = bitlen >> 3;
-	if (cfslave->charbit == 16) {
+	if (cfspi->charbit == 16) {
    	bitlen >>= 1;
    	spi_wr16 = (u16 *) dout;
    	spi_rd16 = (u16 *) din;
@@ -120,25 +239,25 @@ static int cfspi_xfer(struct spi_slave *slave, uint bitlen, const void *dout,
    if ((flags & SPI_XFER_BEGIN) == SPI_XFER_BEGIN)
    	ctrl |= DSPI_TFR_CONT;
-	ctrl = (ctrl & 0xFF000000) | ((1 << slave->cs) << 16);
+	ctrl = (ctrl & 0xFF000000) | ((1 << cs) << 16);
if (len > 1) {
    	int tmp_len = len - 1;
    	while (tmp_len--) {
    		if (dout != NULL) {
-				if (cfslave->charbit == 16)
-					cfspi_tx(ctrl, *spi_wr16++);
+				if (cfspi->charbit == 16)
+					__cfspi_tx(ctrl, *spi_wr16++);
    			else
-					cfspi_tx(ctrl, *spi_wr++);
-				cfspi_rx();
+					__cfspi_tx(ctrl, *spi_wr++);
+				__cfspi_rx();
    		}
if (din != NULL) {
-				cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
-				if (cfslave->charbit == 16)
-					*spi_rd16++ = cfspi_rx();
+				__cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
+				if (cfspi->charbit == 16)
+					*spi_rd16++ = __cfspi_rx();
    			else
-					*spi_rd++ = cfspi_rx();
+					*spi_rd++ = __cfspi_rx();
    		}
    	}
@@ -150,186 +269,188 @@ static int cfspi_xfer(struct spi_slave *slave, uint bitlen, const void *dout,
if (len) {
    	if (dout != NULL) {
-			if (cfslave->charbit == 16)
-				cfspi_tx(ctrl, *spi_wr16);
+			if (cfspi->charbit == 16)
+				__cfspi_tx(ctrl, *spi_wr16);
    		else
-				cfspi_tx(ctrl, *spi_wr);
-			cfspi_rx();
+				__cfspi_tx(ctrl, *spi_wr);
+			__cfspi_rx();
    	}
if (din != NULL) {
-			cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
-			if (cfslave->charbit == 16)
-				*spi_rd16 = cfspi_rx();
+			__cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
+			if (cfspi->charbit == 16)
+				*spi_rd16 = __cfspi_rx();
    		else
-				*spi_rd = cfspi_rx();
+				*spi_rd = __cfspi_rx();
    	}
    } else {
    	/* dummy read */
-		cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
-		cfspi_rx();
+		__cfspi_tx(ctrl, CONFIG_SPI_IDLE_VAL);
+		__cfspi_rx();
    }
return 0;
 }
-static struct spi_slave *cfspi_setup_slave(struct cf_spi_slave *cfslave,
-					   uint mode)
+#ifndef CONFIG_DM_SPI
+
+static inline struct coldfire_spi_priv *to_coldfire_spi_slave
+		(struct spi_slave *slave)
 {
-	/*
-	 * bit definition for mode:
-	 * bit 31 - 28: Transfer size 3 to 16 bits
-	 *     27 - 26: PCS to SCK delay prescaler
-	 *     25 - 24: After SCK delay prescaler
-	 *     23 - 22: Delay after transfer prescaler
-	 *     21     : Allow overwrite for bit 31-22 and bit 20-8
-	 *     20     : Double baud rate
-	 *     19 - 16: PCS to SCK delay scaler
-	 *     15 - 12: After SCK delay scaler
-	 *     11 -  8: Delay after transfer scaler
-	 *      7 -  0: SPI_CPHA, SPI_CPOL, SPI_LSB_FIRST
-	 */
-	volatile dspi_t *dspi = (dspi_t *) MMAP_DSPI;
-	int prescaler[] = { 2, 3, 5, 7 };
-	int scaler[] = {
-		2, 4, 6, 8,
-		16, 32, 64, 128,
-		256, 512, 1024, 2048,
-		4096, 8192, 16384, 32768
-	};
-	int i, j, pbrcnt, brcnt, diff, tmp, dbr = 0;
-	int best_i, best_j, bestmatch = 0x7FFFFFFF, baud_speed;
-	u32 bus_setup = 0;
+	return container_of(slave, struct coldfire_spi_priv, slave);
+}
-	tmp = (prescaler[3] * scaler[15]);
-	/* Maximum and minimum baudrate it can handle */
-	if ((cfslave->baudrate > (gd->bus_clk >> 1)) ||
-	    (cfslave->baudrate < (gd->bus_clk / tmp))) {
-		printf("Exceed baudrate limitation: Max %d - Min %d\n",
-		       (int)(gd->bus_clk >> 1), (int)(gd->bus_clk / tmp));
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+				  unsigned int max_hz, unsigned int mode)
+{
+	struct coldfire_spi_priv *cfspi;
+
+	if (!spi_cs_is_valid(bus, cs))
    	return NULL;
-	}
-	/* Activate Double Baud when it exceed 1/4 the bus clk */
-	if ((CONFIG_SYS_DSPI_CTAR0 & DSPI_CTAR_DBR) ||
-	    (cfslave->baudrate > (gd->bus_clk / (prescaler[0] * scaler[0])))) {
-		bus_setup |= DSPI_CTAR_DBR;
-		dbr = 1;
-	}
+	cfspi = spi_alloc_slave(struct coldfire_spi_priv, bus, cs);
+	if (!cfspi)
+		return NULL;
-	if (mode & SPI_CPOL)
-		bus_setup |= DSPI_CTAR_CPOL;
-	if (mode & SPI_CPHA)
-		bus_setup |= DSPI_CTAR_CPHA;
-	if (mode & SPI_LSB_FIRST)
-		bus_setup |= DSPI_CTAR_LSBFE;
+	cfspi->baudrate = max_hz;
-	/* Overwrite default value set in platform configuration file */
-	if (mode & SPI_MODE_MOD) {
+	if (__spi_set_speed(cfspi, bus, mode))
+		return NULL;
-		if ((mode & 0xF0000000) == 0)
-			bus_setup |=
-			    dspi->ctar[cfslave->slave.bus] & 0x78000000;
-		else
-			bus_setup |= ((mode & 0xF0000000) >> 1);
+	if (__spi_set_mode(cfspi, bus, mode))
+		return NULL;
-		/*
-		 * Check to see if it is enabled by default in platform
-		 * config, or manual setting passed by mode parameter
-		 */
-		if (mode & SPI_DBLRATE) {
-			bus_setup |= DSPI_CTAR_DBR;
-			dbr = 1;
-		}
-		bus_setup |= (mode & 0x0FC00000) >> 4;	/* PSCSCK, PASC, PDT */
-		bus_setup |= (mode & 0x000FFF00) >> 4;	/* CSSCK, ASC, DT */
-	} else
-		bus_setup |= (dspi->ctar[cfslave->slave.bus] & 0x78FCFFF0);
+	return &cfspi->slave;
+}
-	cfslave->charbit =
-	    ((dspi->ctar[cfslave->slave.bus] & 0x78000000) ==
-	     0x78000000) ? 16 : 8;
+int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+{
+	if (((cs >= 0) && (cs < 8)) && ((bus >= 0) && (bus < 8)))
+		return 1;
+	else
+		return 0;
+}
-	pbrcnt = sizeof(prescaler) / sizeof(int);
-	brcnt = sizeof(scaler) / sizeof(int);
+void spi_init(void)
+{
+	__spi_init();
+}
-	/* baudrate calculation - to closer value, may not be exact match */
-	for (best_i = 0, best_j = 0, i = 0; i < pbrcnt; i++) {
-		baud_speed = gd->bus_clk / prescaler[i];
-		for (j = 0; j < brcnt; j++) {
-			tmp = (baud_speed / scaler[j]) * (1 + dbr);
+void spi_free_slave(struct spi_slave *slave)
+{
+	struct coldfire_spi_priv *cfspi = to_coldfire_spi_slave(slave);
-			if (tmp > cfslave->baudrate)
-				diff = tmp - cfslave->baudrate;
-			else
-				diff = cfslave->baudrate - tmp;
+	free(cfspi);
+}
-			if (diff < bestmatch) {
-				bestmatch = diff;
-				best_i = i;
-				best_j = j;
-			}
-		}
-	}
-	bus_setup |= (DSPI_CTAR_PBR(best_i) | DSPI_CTAR_BR(best_j));
-	dspi->ctar[cfslave->slave.bus] = bus_setup;
+int spi_claim_bus(struct spi_slave *slave)
+{
+	return cfspi_claim_bus(slave->bus, slave->cs);
+}
-	return &cfslave->slave;
+void spi_release_bus(struct spi_slave *slave)
+{
+	cfspi_release_bus(slave->bus, slave->cs);
 }
-#endif				/* CONFIG_CF_DSPI */
-#ifdef CONFIG_CMD_SPI
-int spi_cs_is_valid(unsigned int bus, unsigned int cs)
+int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+	     void *din, unsigned long flags)
 {
-	if (((cs >= 0) && (cs < 8)) && ((bus >= 0) && (bus < 8)))
-		return 1;
-	else
-		return 0;
+	struct coldfire_spi_priv *cfspi = to_coldfire_spi_slave(slave);
+
+	return __spi_xfer(cfspi, slave->cs, bitlen, dout, din, flags);
 }
+#else
+
 void spi_init(void)
 {
-	cfspi_init();
+	/* arch-related port configuration */
+	__spi_init();
 }
-struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
-				  unsigned int max_hz, unsigned int mode)
+static int coldfire_spi_claim_bus(struct udevice *dev)
 {
-	struct cf_spi_slave *cfslave;
+	struct udevice *bus = dev_get_parent(dev);
+	struct coldfire_spi_platdata *plat = dev_get_platdata(bus);
-	if (!spi_cs_is_valid(bus, cs))
-		return NULL;
+	return cfspi_claim_bus(bus->seq, plat->cs);
+}
-	cfslave = spi_alloc_slave(struct cf_spi_slave, bus, cs);
-	if (!cfslave)
-		return NULL;
+static int coldfire_spi_release_bus(struct udevice *dev)
+{
+	struct udevice *bus = dev_get_parent(dev);
+	struct coldfire_spi_platdata *plat = dev_get_platdata(bus);
-	cfslave->baudrate = max_hz;
+	cfspi_release_bus(bus->seq, plat->cs);
-	/* specific setup */
-	return cfspi_setup_slave(cfslave, mode);
+	return 0;
 }
-void spi_free_slave(struct spi_slave *slave)
+static int coldfire_spi_xfer(struct udevice *dev, unsigned int bitlen,
+			     const void *dout, void *din,
+			     unsigned long flags)
 {
-	struct cf_spi_slave *cfslave = to_cf_spi_slave(slave);
+	struct udevice *bus = dev_get_parent(dev);
+	struct coldfire_spi_platdata *plat = dev_get_platdata(bus);
+	struct coldfire_spi_priv *cfspi = dev_get_priv(bus);
-	free(cfslave);
+	return __spi_xfer(cfspi, plat->cs, bitlen, dout, din, flags);
 }
-int spi_claim_bus(struct spi_slave *slave)
+static int coldfire_spi_set_speed(struct udevice *bus, uint max_hz)
 {
-	return cfspi_claim_bus(slave->bus, slave->cs);
+	struct coldfire_spi_platdata *plat = dev_get_platdata(bus);
+	struct coldfire_spi_priv *cfspi = dev_get_priv(bus);
+
+	return __spi_set_speed(cfspi, bus->seq, plat->mode);
 }
-void spi_release_bus(struct spi_slave *slave)
+static int coldfire_spi_set_mode(struct udevice *bus, uint mode)
 {
-	cfspi_release_bus(slave->bus, slave->cs);
+	struct coldfire_spi_platdata *plat = dev_get_platdata(bus);
+	struct coldfire_spi_priv *cfspi = dev_get_priv(bus);
+
+	return __spi_set_mode(cfspi, bus->seq, plat->mode);
 }
-int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
-	     void *din, unsigned long flags)
+static int coldfire_spi_probe(struct udevice *bus)
+{
+	struct coldfire_spi_platdata *plat = dev_get_platdata(bus);
+	struct coldfire_spi_priv *cfspi = dev_get_priv(bus);
+
+	cfspi->baudrate = plat->speed_hz;
+
+	return 0;
+}
+
+static int coldfire_spi_ofdata_to_platdata(struct udevice *dev)
 {
-	return cfspi_xfer(slave, bitlen, dout, din, flags);
+        return -ENODEV;
 }
-#endif				/* CONFIG_CMD_SPI */
+
+static const struct udevice_id coldfire_spi_ids[] = {
+        { .compatible = "fsl,mcf-dspi" },
+        { }
+};
+
+
+static const struct dm_spi_ops coldfire_spi_ops = {
+	.claim_bus	= coldfire_spi_claim_bus,
+	.release_bus	= coldfire_spi_release_bus,
+	.xfer		= coldfire_spi_xfer,
+	.set_speed	= coldfire_spi_set_speed,
+	.set_mode	= coldfire_spi_set_mode,
+};
+
+U_BOOT_DRIVER(coldfire_spi) = {
+	.name = "spi_coldfire",
+	.id = UCLASS_SPI,
+	.of_match = coldfire_spi_ids,
+	.probe = coldfire_spi_probe,
+	.ops = &coldfire_spi_ops,
+	.priv_auto_alloc_size = sizeof(struct coldfire_spi_priv),
+	.platdata_auto_alloc_size = sizeof(struct coldfire_spi_platdata),
+};
+#endif				/* CONFIG_DM_SPI */
+#endif				/* CONFIG_CF_DSPI */
diff --git a/include/dm/platform_data/spi_coldfire.h b/include/dm/platform_data/spi_coldfire.h
new file mode 100644
index 0000000000..44094b428d
--- /dev/null
+++ b/include/dm/platform_data/spi_coldfire.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2015  Angelo Dureghello angelo@sysam.it
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#ifndef __spi_coldfire_h
+#define __spi_coldfire_h
+
+/*
+ * struct coldfire_spi_platdata - information about a coldfire spi module
+ *
+ * @speed_hz: SPI speed
+ */
+struct coldfire_spi_platdata {
+	uint speed_hz;
+	uint mode;
+	uint cs;
+};
+
+#endif /* __spi_coldfire_h */
+
-- 
2.17.0


    