atmel_spi: clean up SPIv1 quirk handling

Currently, we have a flag called "new_1" which is basically equivalent
to cpu_is_at91rm9200(). The latter is also called directly a few places.

Clean up this mess by introducing a atmel_spi_v2() function for
determining the controller version, and move all version dependent code
over to use it. This allows us to remove the new_1 flag.

Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c
index 8abae4a..b4f7f1c 100644 (file)
--- a/drivers/spi/atmel_spi.c
+++ b/drivers/spi/atmel_spi.c
@@ -30,13 +30,6 @@
  * The core SPI transfer engine just talks to a register bank to set up
  * DMA transfers; transfer queue progress is driven by IRQs.  The clock
  * framework provides the base clock, subdivided for each spi_device.
- *
- * Newer controllers, marked with "new_1" flag, have:
- *  - CR.LASTXFER
- *  - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero)
- *  - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
- *  - SPI_CSRx.CSAAT
- *  - SPI_CSRx.SBCR allows faster clocking
  */
 struct atmel_spi {
        spinlock_t              lock;
@@ -45,7 +38,6 @@ struct atmel_spi {
        int                     irq;
        struct clk              *clk;
        struct platform_device  *pdev;
-       unsigned                new_1:1;
        struct spi_device       *stay;
 
        u8                      stopping;
@@ -63,6 +55,23 @@ struct atmel_spi {
 #define INVALID_DMA_ADDRESS    0xffffffff
 
 /*
+ * Version 2 of the SPI controller has
+ *  - CR.LASTXFER
+ *  - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero)
+ *  - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs)
+ *  - SPI_CSRx.CSAAT
+ *  - SPI_CSRx.SBCR allows faster clocking
+ *
+ * We can determine the controller version by reading the VERSION
+ * register, but I haven't checked that it exists on all chips, and
+ * this is cheaper anyway.
+ */
+static bool atmel_spi_is_v2(void)
+{
+       return !cpu_is_at91rm9200();
+}
+
+/*
  * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby
  * they assume that spi slave device state will not change on deselect, so
  * that automagic deselection is OK.  ("NPCSx rises if no data is to be
@@ -105,7 +114,7 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi)
                        gpio, active ? " (high)" : "",
                        mr);
 
-       if (!(cpu_is_at91rm9200() && spi->chip_select == 0))
+       if (atmel_spi_is_v2() || spi->chip_select != 0)
                gpio_set_value(gpio, active);
        spi_writel(as, MR, mr);
 }
@@ -129,7 +138,7 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi)
                        gpio, active ? " (low)" : "",
                        mr);
 
-       if (!(cpu_is_at91rm9200() && spi->chip_select == 0))
+       if (atmel_spi_is_v2() || spi->chip_select != 0)
                gpio_set_value(gpio, !active);
 }
 
@@ -536,19 +545,16 @@ static int atmel_spi_setup(struct spi_device *spi)
        }
 
        /* see notes above re chipselect */
-       if (cpu_is_at91rm9200()
+       if (!atmel_spi_is_v2()
                        && spi->chip_select == 0
                        && (spi->mode & SPI_CS_HIGH)) {
                dev_dbg(&spi->dev, "setup: can't be active-high\n");
                return -EINVAL;
        }
 
-       /*
-        * Pre-new_1 chips start out at half the peripheral
-        * bus speed.
-        */
+       /* v1 chips start out at half the peripheral bus speed. */
        bus_hz = clk_get_rate(as->clk);
-       if (!as->new_1)
+       if (!atmel_spi_is_v2())
                bus_hz /= 2;
 
        if (spi->max_speed_hz) {
@@ -755,8 +761,6 @@ static int __init atmel_spi_probe(struct platform_device *pdev)
                goto out_free_buffer;
        as->irq = irq;
        as->clk = clk;
-       if (!cpu_is_at91rm9200())
-               as->new_1 = 1;
 
        ret = request_irq(irq, atmel_spi_interrupt, 0,
                        pdev->dev.bus_id, master);