Commit b8d4e2ce authored by Luotao Fu's avatar Luotao Fu Committed by Grant Likely
Browse files

mpc52xx_spi: add gpio chipselect 



This one enables the mpc52xx_spi driver for usage of user defined gpio lines
as chipselect. This way we can control some more spi devices than only one

V2 Changes:
* preinitialize the gpio as output in probe function and call gpio_set_value in
  the chip select function instead of calling direction_output every time.
* initialize the gpio line with output high, since we don't support CS_HIGH
  in the driver currently any way. change gpio value setting to default active
  low in chip select call.
* free the gpio array while error or removing.

Signed-off-by: default avatarLuotao Fu <l.fu@pengutronix.de>
Acked-by: default avatarWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent d65aea99

drivers/spi/mpc52xx_spi.c

+60 −4
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 
#include <linux/spi/mpc52xx_spi.h>

#include <linux/of_spi.h>

#include <linux/io.h>

#include <linux/of_gpio.h>

#include <asm/time.h>

#include <asm/mpc52xx.h>
@@ -79,7 +80,6 @@ struct mpc52xx_spi { 
	spinlock_t lock;

	struct work_struct work;





	/* Details of current transfer (length, and buffer pointers) */

	struct spi_message *message;	/* current message */

	struct spi_transfer *transfer;	/* current transfer */
@@ -89,6 +89,8 @@ struct mpc52xx_spi { 
	u8 *rx_buf;

	const u8 *tx_buf;

	int cs_change;

	int gpio_cs_count;

	unsigned int *gpio_cs;

};



/*
@@ -96,6 +98,12 @@ struct mpc52xx_spi { 
 */

static void mpc52xx_spi_chipsel(struct mpc52xx_spi *ms, int value)

{

	int cs;



	if (ms->gpio_cs_count > 0) {

		cs = ms->message->spi->chip_select;

		gpio_set_value(ms->gpio_cs[cs], value ? 0 : 1);

	} else

		out_8(ms->regs + SPI_PORTDATA, value ? 0 : 0x08);

}
@@ -390,8 +398,9 @@ static int __devinit mpc52xx_spi_probe(struct of_device *op, 
	struct spi_master *master;

	struct mpc52xx_spi *ms;

	void __iomem *regs;

	int rc;

	u8 ctrl1;

	int rc, i = 0;

	int gpio_cs;



	/* MMIO registers */

	dev_dbg(&op->dev, "probing mpc5200 SPI device\n");
@@ -426,8 +435,8 @@ static int __devinit mpc52xx_spi_probe(struct of_device *op, 
		rc = -ENOMEM;

		goto err_alloc;

	}



	master->bus_num = -1;

	master->num_chipselect = 1;

	master->setup = mpc52xx_spi_setup;

	master->transfer = mpc52xx_spi_transfer;

	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
@@ -441,6 +450,40 @@ static int __devinit mpc52xx_spi_probe(struct of_device *op, 
	ms->irq1 = irq_of_parse_and_map(op->node, 1);

	ms->state = mpc52xx_spi_fsmstate_idle;

	ms->ipb_freq = mpc5xxx_get_bus_frequency(op->node);

	ms->gpio_cs_count = of_gpio_count(op->node);

	if (ms->gpio_cs_count > 0) {

		master->num_chipselect = ms->gpio_cs_count;

		ms->gpio_cs = kmalloc(ms->gpio_cs_count * sizeof(unsigned int),

				GFP_KERNEL);

		if (!ms->gpio_cs) {

			rc = -ENOMEM;

			goto err_alloc;

		}



		for (i = 0; i < ms->gpio_cs_count; i++) {

			gpio_cs = of_get_gpio(op->node, i);

			if (gpio_cs < 0) {

				dev_err(&op->dev,

					"could not parse the gpio field "

					"in oftree\n");

				rc = -ENODEV;

				goto err_gpio;

			}



			rc = gpio_request(gpio_cs, dev_name(&op->dev));

			if (rc) {

				dev_err(&op->dev,

					"can't request spi cs gpio #%d "

					"on gpio line %d\n", i, gpio_cs);

				goto err_gpio;

			}



			gpio_direction_output(gpio_cs, 1);

			ms->gpio_cs[i] = gpio_cs;

		}

	} else

		master->num_chipselect = 1;



	spin_lock_init(&ms->lock);

	INIT_LIST_HEAD(&ms->queue);

	INIT_WORK(&ms->work, mpc52xx_spi_wq);
@@ -477,6 +520,12 @@ static int __devinit mpc52xx_spi_probe(struct of_device *op, 
 err_register:

	dev_err(&ms->master->dev, "initialization failed\n");

	spi_master_put(master);

 err_gpio:

	while (i-- > 0)

		gpio_free(ms->gpio_cs[i]);



	if (ms->gpio_cs != NULL)

		kfree(ms->gpio_cs);

 err_alloc:

 err_init:

	iounmap(regs);
@@ -487,10 +536,17 @@ static int __devexit mpc52xx_spi_remove(struct of_device *op) 
{

	struct spi_master *master = dev_get_drvdata(&op->dev);

	struct mpc52xx_spi *ms = spi_master_get_devdata(master);

	int i;



	free_irq(ms->irq0, ms);

	free_irq(ms->irq1, ms);



	for (i = 0; i < ms->gpio_cs_count; i++)

		gpio_free(ms->gpio_cs[i]);



	if (ms->gpio_cs != NULL)

		kfree(ms->gpio_cs);



	spi_unregister_master(master);

	spi_master_put(master);

	iounmap(ms->regs);

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