From b8d4e2ce60b63294e3408d1c5211b8a8dc4af095 Mon Sep 17 00:00:00 2001 From: Luotao Fu Date: Fri, 13 Nov 2009 10:41:17 +0100 Subject: [PATCH] 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: Luotao Fu Acked-by: Wolfram Sang Signed-off-by: Grant Likely --- drivers/spi/mpc52xx_spi.c | 64 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 60 insertions(+), 4 deletions(-) diff --git a/drivers/spi/mpc52xx_spi.c b/drivers/spi/mpc52xx_spi.c index 64862cfda19e..97beba2895e7 100644 --- a/drivers/spi/mpc52xx_spi.c +++ b/drivers/spi/mpc52xx_spi.c @@ -21,6 +21,7 @@ #include #include #include +#include #include #include @@ -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); 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); -- 2.20.1