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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/ |
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