[PATCH 1/2] spi: mpc512x-psc: Use the framework .set_cs()

STALE2199d

3 messages, 2 authors, 2020-07-30 · open the first message on its own page

[PATCH 1/2] spi: mpc512x-psc: Use the framework .set_cs()

From: Linus Walleij <hidden>
Date: 2020-07-29 21:52:20

The mpc512x-psc is rolling its own chip select control code,
but the SPI master framework can handle this. It was also
evaluating the CS status for each transfer but the CS change
should be per-message not per-transfer.

Switch to use the core .set_cs() to control the chip select.

Cc: Uwe Kleine-König <redacted>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Linus Walleij <redacted>
---
 drivers/spi/spi-mpc512x-psc.c | 30 ++++++++----------------------
 1 file changed, 8 insertions(+), 22 deletions(-)

diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c
index ea1b07953d38..35313a77f977 100644
--- a/drivers/spi/spi-mpc512x-psc.c
+++ b/drivers/spi/spi-mpc512x-psc.c

@@ -89,7 +89,7 @@ static int mpc512x_psc_spi_transfer_setup(struct spi_device *spi,
 	return 0;
 }
 
-static void mpc512x_psc_spi_activate_cs(struct spi_device *spi)
+static void mpc512x_psc_spi_set_cs(struct spi_device *spi, bool enable)
 {
 	struct mpc512x_psc_spi_cs *cs = spi->controller_state;
 	struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);

@@ -98,6 +98,12 @@ static void mpc512x_psc_spi_activate_cs(struct spi_device *spi)
 	int speed;
 	u16 bclkdiv;
 
+	if (!enable) {
+		if (mps->cs_control && gpio_is_valid(spi->cs_gpio))
+			mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
+		return;
+	}
+
 	sicr = in_be32(psc_addr(mps, sicr));
 
 	/* Set clock phase and polarity */

@@ -132,15 +138,6 @@ static void mpc512x_psc_spi_activate_cs(struct spi_device *spi)
 		mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0);
 }
 
-static void mpc512x_psc_spi_deactivate_cs(struct spi_device *spi)
-{
-	struct mpc512x_psc_spi *mps = spi_master_get_devdata(spi->master);
-
-	if (mps->cs_control && gpio_is_valid(spi->cs_gpio))
-		mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
-
-}
-
 /* extract and scale size field in txsz or rxsz */
 #define MPC512x_PSC_FIFO_SZ(sz) ((sz & 0x7ff) << 2);

@@ -290,40 +287,28 @@ static int mpc512x_psc_spi_msg_xfer(struct spi_master *master,
 				    struct spi_message *m)
 {
 	struct spi_device *spi;
-	unsigned cs_change;
 	int status;
 	struct spi_transfer *t;
 
 	spi = m->spi;
-	cs_change = 1;
 	status = 0;
 	list_for_each_entry(t, &m->transfers, transfer_list) {
 		status = mpc512x_psc_spi_transfer_setup(spi, t);
 		if (status < 0)
 			break;
 
-		if (cs_change)
-			mpc512x_psc_spi_activate_cs(spi);
-		cs_change = t->cs_change;
-
 		status = mpc512x_psc_spi_transfer_rxtx(spi, t);
 		if (status)
 			break;
 		m->actual_length += t->len;
 
 		spi_transfer_delay_exec(t);
-
-		if (cs_change)
-			mpc512x_psc_spi_deactivate_cs(spi);
 	}
 
 	m->status = status;
 	if (m->complete)
 		m->complete(m->context);
 
-	if (status || !cs_change)
-		mpc512x_psc_spi_deactivate_cs(spi);
-
 	mpc512x_psc_spi_transfer_setup(spi, NULL);
 
 	spi_finalize_current_message(master);

@@ -513,6 +498,7 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 	master->prepare_transfer_hardware = mpc512x_psc_spi_prep_xfer_hw;
 	master->transfer_one_message = mpc512x_psc_spi_msg_xfer;
 	master->unprepare_transfer_hardware = mpc512x_psc_spi_unprep_xfer_hw;
+	master->set_cs = mpc512x_psc_spi_set_cs;
 	master->cleanup = mpc512x_psc_spi_cleanup;
 	master->dev.of_node = dev->of_node;

-- 
2.26.2

[PATCH 2/2] spi: mpc512x-psc: Convert to use GPIO descriptors

From: Linus Walleij <hidden>
Date: 2020-07-29 21:54:20

This driver is already relying on the core to provide
valid GPIO numbers in spi->cs_gpio through
of_spi_get_gpio_numbers(), so we can switch to letting
the core use GPIO descriptors instead.

Make sure that the .set_cs() is always called, as some controller
set-up is also needed.

Cc: Uwe Kleine-König <redacted>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Linus Walleij <redacted>
---
 drivers/spi/spi-mpc512x-psc.c | 33 +++++++--------------------------
 1 file changed, 7 insertions(+), 26 deletions(-)

diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c
index 35313a77f977..dd8bba408301 100644
--- a/drivers/spi/spi-mpc512x-psc.c
+++ b/drivers/spi/spi-mpc512x-psc.c

@@ -23,7 +23,6 @@
 #include <linux/clk.h>
 #include <linux/spi/spi.h>
 #include <linux/fsl_devices.h>
-#include <linux/gpio.h>
 #include <asm/mpc52xx_psc.h>
 
 enum {

@@ -99,7 +98,7 @@ static void mpc512x_psc_spi_set_cs(struct spi_device *spi, bool enable)
 	u16 bclkdiv;
 
 	if (!enable) {
-		if (mps->cs_control && gpio_is_valid(spi->cs_gpio))
+		if (mps->cs_control && spi->cs_gpiod)
 			mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 0 : 1);
 		return;
 	}

@@ -134,7 +133,7 @@ static void mpc512x_psc_spi_set_cs(struct spi_device *spi, bool enable)
 	out_be32(psc_addr(mps, ccr), ccr);
 	mps->bits_per_word = cs->bits_per_word;
 
-	if (mps->cs_control && gpio_is_valid(spi->cs_gpio))
+	if (mps->cs_control && spi->cs_gpiod)
 		mps->cs_control(spi, (spi->mode & SPI_CS_HIGH) ? 1 : 0);
 }

@@ -358,18 +357,6 @@ static int mpc512x_psc_spi_setup(struct spi_device *spi)
 		if (!cs)
 			return -ENOMEM;
 
-		if (gpio_is_valid(spi->cs_gpio)) {
-			ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
-			if (ret) {
-				dev_err(&spi->dev, "can't get CS gpio: %d\n",
-					ret);
-				kfree(cs);
-				return ret;
-			}
-			gpio_direction_output(spi->cs_gpio,
-					spi->mode & SPI_CS_HIGH ? 0 : 1);
-		}
-
 		spi->controller_state = cs;
 	}

@@ -381,8 +368,6 @@ static int mpc512x_psc_spi_setup(struct spi_device *spi)
 
 static void mpc512x_psc_spi_cleanup(struct spi_device *spi)
 {
-	if (gpio_is_valid(spi->cs_gpio))
-		gpio_free(spi->cs_gpio);
 	kfree(spi->controller_state);
 }

@@ -461,11 +446,6 @@ static irqreturn_t mpc512x_psc_spi_isr(int irq, void *dev_id)
 	return IRQ_NONE;
 }
 
-static void mpc512x_spi_cs_control(struct spi_device *spi, bool onoff)
-{
-	gpio_set_value(spi->cs_gpio, onoff);
-}
-
 static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 					      u32 size, unsigned int irq)
 {

@@ -485,10 +465,8 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 	mps->type = (int)of_device_get_match_data(dev);
 	mps->irq = irq;
 
-	if (pdata == NULL) {
-		mps->cs_control = mpc512x_spi_cs_control;
-	} else {
-		mps->cs_control = pdata->cs_control;
+	if (pdata) {
+		mps->cs_control = pdata->cs_control;x
 		master->bus_num = pdata->bus_num;
 		master->num_chipselect = pdata->max_chipselect;
 	}

@@ -499,6 +477,9 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 	master->transfer_one_message = mpc512x_psc_spi_msg_xfer;
 	master->unprepare_transfer_hardware = mpc512x_psc_spi_unprep_xfer_hw;
 	master->set_cs = mpc512x_psc_spi_set_cs;
+	/* This makes sure our custom .set_cs() is always called */
+	master->flags = SPI_MASTER_GPIO_SS;
+	master->use_gpio_descriptors = true;
 	master->cleanup = mpc512x_psc_spi_cleanup;
 	master->dev.of_node = dev->of_node;

-- 
2.26.2

Re: [PATCH 1/2] spi: mpc512x-psc: Use the framework .set_cs()

From: Mark Brown <broonie@kernel.org>
Date: 2020-07-30 10:41:00

On Wed, Jul 29, 2020 at 11:48:16PM +0200, Linus Walleij wrote:

The mpc512x-psc is rolling its own chip select control code,
but the SPI master framework can handle this. It was also
evaluating the CS status for each transfer but the CS change
should be per-message not per-transfer.

No, CS change is per transfer.

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