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SubjectRe: [PATCH 3/3] [V2] mpc52xx_spi: add gpio chipselect
On Fri, Nov 13, 2009 at 11:41:17AM +0100, Luotao Fu wrote:
> 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: Luotao Fu <l.fu@pengutronix.de>

Just the kfree-comment, otherwise:

Acked-by: Wolfram Sang <w.sang@pengutronix.de>

> ---
> drivers/spi/mpc52xx_spi.c | 64 ++++++++++++++++++++++++++++++++++++++++++---
> 1 files changed, 60 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/spi/mpc52xx_spi.c b/drivers/spi/mpc52xx_spi.c
> index 64862cf..97beba2 100644
> --- a/drivers/spi/mpc52xx_spi.c
> +++ b/drivers/spi/mpc52xx_spi.c
> @@ -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;
> };
>
> /*
> @@ -96,7 +98,13 @@ struct mpc52xx_spi {
> */
> static void mpc52xx_spi_chipsel(struct mpc52xx_spi *ms, int value)
> {
> - out_8(ms->regs + SPI_PORTDATA, value ? 0 : 0x08);
> + 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);

kfree() is NULL aware, so no if needed.

> 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);

ditto.

> +
> spi_unregister_master(master);
> spi_master_put(master);
> iounmap(ms->regs);
> --
> 1.6.5.2
>
> _______________________________________________
> Linuxppc-dev mailing list
> Linuxppc-dev@lists.ozlabs.org
> https://lists.ozlabs.org/listinfo/linuxppc-dev

--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |[unhandled content-type:application/pgp-signature]
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