.driver = {
.name = "CHIP",
.owner = THIS_MODULE,
+ .pm = &CHIP_pm_ops,
},
.probe = CHIP_probe,
.remove = CHIP_remove,
- .suspend = CHIP_suspend,
- .resume = CHIP_resume,
};
The driver core will automatically attempt to bind this driver to any SPI
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
return ret;
}
-static int omap1_spi100k_prepare_hardware(struct spi_master *master)
-{
- struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
-
- clk_prepare_enable(spi100k->ick);
- clk_prepare_enable(spi100k->fck);
-
- return 0;
-}
-
static int omap1_spi100k_transfer_one_message(struct spi_master *master,
struct spi_message *m)
{
return status;
}
-static int omap1_spi100k_unprepare_hardware(struct spi_master *master)
-{
- struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
-
- clk_disable_unprepare(spi100k->ick);
- clk_disable_unprepare(spi100k->fck);
-
- return 0;
-}
-
static int omap1_spi100k_probe(struct platform_device *pdev)
{
struct spi_master *master;
master->setup = omap1_spi100k_setup;
master->transfer_one_message = omap1_spi100k_transfer_one_message;
- master->prepare_transfer_hardware = omap1_spi100k_prepare_hardware;
- master->unprepare_transfer_hardware = omap1_spi100k_unprepare_hardware;
- master->cleanup = NULL;
master->num_chipselect = 2;
master->mode_bits = MODEBITS;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
master->min_speed_hz = OMAP1_SPI100K_MAX_FREQ/(1<<16);
master->max_speed_hz = OMAP1_SPI100K_MAX_FREQ;
+ master->auto_runtime_pm = true;
spi100k = spi_master_get_devdata(master);
goto err;
}
+ status = clk_prepare_enable(spi100k->ick);
+ if (status != 0) {
+ dev_err(&pdev->dev, "failed to enable ick: %d\n", status);
+ goto err;
+ }
+
+ status = clk_prepare_enable(spi100k->fck);
+ if (status != 0) {
+ dev_err(&pdev->dev, "failed to enable fck: %d\n", status);
+ goto err_ick;
+ }
+
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_set_active(&pdev->dev);
+
status = devm_spi_register_master(&pdev->dev, master);
if (status < 0)
- goto err;
+ goto err_fck;
return status;
+err_fck:
+ clk_disable_unprepare(spi100k->fck);
+err_ick:
+ clk_disable_unprepare(spi100k->ick);
err:
spi_master_put(master);
return status;
}
+static int omap1_spi100k_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = spi_master_get(platform_get_drvdata(pdev));
+ struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+
+ pm_runtime_disable(&pdev->dev);
+
+ clk_disable_unprepare(spi100k->fck);
+ clk_disable_unprepare(spi100k->ick);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int omap1_spi100k_runtime_suspend(struct device *dev)
+{
+ struct spi_master *master = spi_master_get(dev_get_drvdata(dev));
+ struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+
+ clk_disable_unprepare(spi100k->ick);
+ clk_disable_unprepare(spi100k->fck);
+
+ return 0;
+}
+
+static int omap1_spi100k_runtime_resume(struct device *dev)
+{
+ struct spi_master *master = spi_master_get(dev_get_drvdata(dev));
+ struct omap1_spi100k *spi100k = spi_master_get_devdata(master);
+ int ret;
+
+ ret = clk_prepare_enable(spi100k->ick);
+ if (ret != 0) {
+ dev_err(dev, "Failed to enable ick: %d\n", ret);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(spi100k->fck);
+ if (ret != 0) {
+ dev_err(dev, "Failed to enable fck: %d\n", ret);
+ clk_disable_unprepare(spi100k->ick);
+ return ret;
+ }
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops omap1_spi100k_pm = {
+ SET_RUNTIME_PM_OPS(omap1_spi100k_runtime_suspend,
+ omap1_spi100k_runtime_resume, NULL)
+};
+
static struct platform_driver omap1_spi100k_driver = {
.driver = {
.name = "omap1_spi100k",
+ .pm = &omap1_spi100k_pm,
},
.probe = omap1_spi100k_probe,
+ .remove = omap1_spi100k_remove,
};
module_platform_driver(omap1_spi100k_driver);
#include <linux/module.h>
#include <linux/io.h>
-#include <asm/irq.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>
*/
#define DEFAULT_SSP_REG_IMSC 0x0UL
#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
-#define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC)
+#define ENABLE_ALL_INTERRUPTS ( \
+ SSP_IMSC_MASK_RORIM | \
+ SSP_IMSC_MASK_RTIM | \
+ SSP_IMSC_MASK_RXIM | \
+ SSP_IMSC_MASK_TXIM \
+)
#define CLEAR_ALL_INTERRUPTS 0x3
struct pl022 *pl022 = dev_id;
struct spi_message *msg = pl022->cur_msg;
u16 irq_status = 0;
- u16 flag = 0;
if (unlikely(!msg)) {
dev_err(&pl022->adev->dev,
if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
dev_err(&pl022->adev->dev,
"RXFIFO is full\n");
- if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF)
- dev_err(&pl022->adev->dev,
- "TXFIFO is full\n");
/*
* Disable and clear interrupts, disable SSP,
readwriter(pl022);
- if ((pl022->tx == pl022->tx_end) && (flag == 0)) {
- flag = 1;
+ if (pl022->tx == pl022->tx_end) {
/* Disable Transmit interrupt, enable receive interrupt */
writew((readw(SSP_IMSC(pl022->virtbase)) &
~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/interrupt.h>
+#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/spi/pxa2xx_spi.h>
#include <linux/spi/spi.h>
#include <linux/pm_runtime.h>
#include <linux/acpi.h>
-#include <asm/io.h>
-#include <asm/irq.h>
-#include <asm/delay.h>
-
#include "spi-pxa2xx.h"
MODULE_AUTHOR("Stephen Street");
#define LPSS_TX_LOTHRESH_DFLT 160
#define LPSS_TX_HITHRESH_DFLT 224
-struct quark_spi_rate {
- u32 bitrate;
- u32 dds_clk_rate;
- u32 clk_div;
-};
-
-/*
- * 'rate', 'dds', 'clk_div' lookup table, which is defined in
- * the Quark SPI datasheet.
- */
-static const struct quark_spi_rate quark_spi_rate_table[] = {
-/* bitrate, dds_clk_rate, clk_div */
- {50000000, 0x800000, 0},
- {40000000, 0x666666, 0},
- {25000000, 0x400000, 0},
- {20000000, 0x666666, 1},
- {16667000, 0x800000, 2},
- {13333000, 0x666666, 2},
- {12500000, 0x200000, 0},
- {10000000, 0x800000, 4},
- {8000000, 0x666666, 4},
- {6250000, 0x400000, 3},
- {5000000, 0x400000, 4},
- {4000000, 0x666666, 9},
- {3125000, 0x80000, 0},
- {2500000, 0x400000, 9},
- {2000000, 0x666666, 19},
- {1563000, 0x40000, 0},
- {1250000, 0x200000, 9},
- {1000000, 0x400000, 24},
- {800000, 0x666666, 49},
- {781250, 0x20000, 0},
- {625000, 0x200000, 19},
- {500000, 0x400000, 49},
- {400000, 0x666666, 99},
- {390625, 0x10000, 0},
- {250000, 0x400000, 99},
- {200000, 0x666666, 199},
- {195313, 0x8000, 0},
- {125000, 0x100000, 49},
- {100000, 0x200000, 124},
- {50000, 0x100000, 124},
- {25000, 0x80000, 124},
- {10016, 0x20000, 77},
- {5040, 0x20000, 154},
- {1002, 0x8000, 194},
-};
-
/* Offset from drv_data->lpss_base */
#define GENERAL_REG 0x08
#define GENERAL_REG_RXTO_HOLDOFF_DISABLE BIT(24)
}
/*
- * The Quark SPI data sheet gives a table, and for the given 'rate',
- * the 'dds' and 'clk_div' can be found in the table.
+ * The Quark SPI has an additional 24 bit register (DDS_CLK_RATE) to multiply
+ * input frequency by fractions of 2^24. It also has a divider by 5.
+ *
+ * There are formulas to get baud rate value for given input frequency and
+ * divider parameters, such as DDS_CLK_RATE and SCR:
+ *
+ * Fsys = 200MHz
+ *
+ * Fssp = Fsys * DDS_CLK_RATE / 2^24 (1)
+ * Baud rate = Fsclk = Fssp / (2 * (SCR + 1)) (2)
+ *
+ * DDS_CLK_RATE either 2^n or 2^n / 5.
+ * SCR is in range 0 .. 255
+ *
+ * Divisor = 5^i * 2^j * 2 * k
+ * i = [0, 1] i = 1 iff j = 0 or j > 3
+ * j = [0, 23] j = 0 iff i = 1
+ * k = [1, 256]
+ * Special case: j = 0, i = 1: Divisor = 2 / 5
+ *
+ * Accordingly to the specification the recommended values for DDS_CLK_RATE
+ * are:
+ * Case 1: 2^n, n = [0, 23]
+ * Case 2: 2^24 * 2 / 5 (0x666666)
+ * Case 3: less than or equal to 2^24 / 5 / 16 (0x33333)
+ *
+ * In all cases the lowest possible value is better.
+ *
+ * The function calculates parameters for all cases and chooses the one closest
+ * to the asked baud rate.
*/
-static u32 quark_x1000_set_clk_regvals(u32 rate, u32 *dds, u32 *clk_div)
+static unsigned int quark_x1000_get_clk_div(int rate, u32 *dds)
{
- unsigned int i;
-
- for (i = 0; i < ARRAY_SIZE(quark_spi_rate_table); i++) {
- if (rate >= quark_spi_rate_table[i].bitrate) {
- *dds = quark_spi_rate_table[i].dds_clk_rate;
- *clk_div = quark_spi_rate_table[i].clk_div;
- return quark_spi_rate_table[i].bitrate;
+ unsigned long xtal = 200000000;
+ unsigned long fref = xtal / 2; /* mandatory division by 2,
+ see (2) */
+ /* case 3 */
+ unsigned long fref1 = fref / 2; /* case 1 */
+ unsigned long fref2 = fref * 2 / 5; /* case 2 */
+ unsigned long scale;
+ unsigned long q, q1, q2;
+ long r, r1, r2;
+ u32 mul;
+
+ /* Case 1 */
+
+ /* Set initial value for DDS_CLK_RATE */
+ mul = (1 << 24) >> 1;
+
+ /* Calculate initial quot */
+ q1 = DIV_ROUND_CLOSEST(fref1, rate);
+
+ /* Scale q1 if it's too big */
+ if (q1 > 256) {
+ /* Scale q1 to range [1, 512] */
+ scale = fls_long(q1 - 1);
+ if (scale > 9) {
+ q1 >>= scale - 9;
+ mul >>= scale - 9;
}
+
+ /* Round the result if we have a remainder */
+ q1 += q1 & 1;
}
- *dds = quark_spi_rate_table[i-1].dds_clk_rate;
- *clk_div = quark_spi_rate_table[i-1].clk_div;
+ /* Decrease DDS_CLK_RATE as much as we can without loss in precision */
+ scale = __ffs(q1);
+ q1 >>= scale;
+ mul >>= scale;
+
+ /* Get the remainder */
+ r1 = abs(fref1 / (1 << (24 - fls_long(mul))) / q1 - rate);
+
+ /* Case 2 */
+
+ q2 = DIV_ROUND_CLOSEST(fref2, rate);
+ r2 = abs(fref2 / q2 - rate);
- return quark_spi_rate_table[i-1].bitrate;
+ /*
+ * Choose the best between two: less remainder we have the better. We
+ * can't go case 2 if q2 is greater than 256 since SCR register can
+ * hold only values 0 .. 255.
+ */
+ if (r2 >= r1 || q2 > 256) {
+ /* case 1 is better */
+ r = r1;
+ q = q1;
+ } else {
+ /* case 2 is better */
+ r = r2;
+ q = q2;
+ mul = (1 << 24) * 2 / 5;
+ }
+
+ /* Check case 3 only If the divisor is big enough */
+ if (fref / rate >= 80) {
+ u64 fssp;
+ u32 m;
+
+ /* Calculate initial quot */
+ q1 = DIV_ROUND_CLOSEST(fref, rate);
+ m = (1 << 24) / q1;
+
+ /* Get the remainder */
+ fssp = (u64)fref * m;
+ do_div(fssp, 1 << 24);
+ r1 = abs(fssp - rate);
+
+ /* Choose this one if it suits better */
+ if (r1 < r) {
+ /* case 3 is better */
+ q = 1;
+ mul = m;
+ }
+ }
+
+ *dds = mul;
+ return q - 1;
}
static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate)
rate = min_t(int, ssp_clk, rate);
if (ssp->type == PXA25x_SSP || ssp->type == CE4100_SSP)
- return ((ssp_clk / (2 * rate) - 1) & 0xff) << 8;
+ return (ssp_clk / (2 * rate) - 1) & 0xff;
else
- return ((ssp_clk / rate - 1) & 0xfff) << 8;
+ return (ssp_clk / rate - 1) & 0xfff;
}
static unsigned int pxa2xx_ssp_get_clk_div(struct driver_data *drv_data,
struct chip_data *chip, int rate)
{
- u32 clk_div;
+ unsigned int clk_div;
switch (drv_data->ssp_type) {
case QUARK_X1000_SSP:
- quark_x1000_set_clk_regvals(rate, &chip->dds_rate, &clk_div);
- return clk_div << 8;
+ clk_div = quark_x1000_get_clk_div(rate, &chip->dds_rate);
+ break;
default:
- return ssp_get_clk_div(drv_data, rate);
+ clk_div = ssp_get_clk_div(drv_data, rate);
+ break;
}
+ return clk_div << 8;
}
static void pump_transfers(unsigned long data)
return 0;
}
-#ifdef CONFIG_PM_SLEEP
-static int spi_legacy_suspend(struct device *dev, pm_message_t message)
-{
- int value = 0;
- struct spi_driver *drv = to_spi_driver(dev->driver);
-
- /* suspend will stop irqs and dma; no more i/o */
- if (drv) {
- if (drv->suspend)
- value = drv->suspend(to_spi_device(dev), message);
- else
- dev_dbg(dev, "... can't suspend\n");
- }
- return value;
-}
-
-static int spi_legacy_resume(struct device *dev)
-{
- int value = 0;
- struct spi_driver *drv = to_spi_driver(dev->driver);
-
- /* resume may restart the i/o queue */
- if (drv) {
- if (drv->resume)
- value = drv->resume(to_spi_device(dev));
- else
- dev_dbg(dev, "... can't resume\n");
- }
- return value;
-}
-
-static int spi_pm_suspend(struct device *dev)
-{
- const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
- if (pm)
- return pm_generic_suspend(dev);
- else
- return spi_legacy_suspend(dev, PMSG_SUSPEND);
-}
-
-static int spi_pm_resume(struct device *dev)
-{
- const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
- if (pm)
- return pm_generic_resume(dev);
- else
- return spi_legacy_resume(dev);
-}
-
-static int spi_pm_freeze(struct device *dev)
-{
- const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
- if (pm)
- return pm_generic_freeze(dev);
- else
- return spi_legacy_suspend(dev, PMSG_FREEZE);
-}
-
-static int spi_pm_thaw(struct device *dev)
-{
- const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
- if (pm)
- return pm_generic_thaw(dev);
- else
- return spi_legacy_resume(dev);
-}
-
-static int spi_pm_poweroff(struct device *dev)
-{
- const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
- if (pm)
- return pm_generic_poweroff(dev);
- else
- return spi_legacy_suspend(dev, PMSG_HIBERNATE);
-}
-
-static int spi_pm_restore(struct device *dev)
-{
- const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
-
- if (pm)
- return pm_generic_restore(dev);
- else
- return spi_legacy_resume(dev);
-}
-#else
-#define spi_pm_suspend NULL
-#define spi_pm_resume NULL
-#define spi_pm_freeze NULL
-#define spi_pm_thaw NULL
-#define spi_pm_poweroff NULL
-#define spi_pm_restore NULL
-#endif
-
-static const struct dev_pm_ops spi_pm = {
- .suspend = spi_pm_suspend,
- .resume = spi_pm_resume,
- .freeze = spi_pm_freeze,
- .thaw = spi_pm_thaw,
- .poweroff = spi_pm_poweroff,
- .restore = spi_pm_restore,
- SET_RUNTIME_PM_OPS(
- pm_generic_runtime_suspend,
- pm_generic_runtime_resume,
- NULL
- )
-};
-
struct bus_type spi_bus_type = {
.name = "spi",
.dev_groups = spi_dev_groups,
.match = spi_match_device,
.uevent = spi_uevent,
- .pm = &spi_pm,
};
EXPORT_SYMBOL_GPL(spi_bus_type);
* @remove: Unbinds this driver from the spi device
* @shutdown: Standard shutdown callback used during system state
* transitions such as powerdown/halt and kexec
- * @suspend: Standard suspend callback used during system state transitions
- * @resume: Standard resume callback used during system state transitions
* @driver: SPI device drivers should initialize the name and owner
* field of this structure.
*
int (*probe)(struct spi_device *spi);
int (*remove)(struct spi_device *spi);
void (*shutdown)(struct spi_device *spi);
- int (*suspend)(struct spi_device *spi, pm_message_t mesg);
- int (*resume)(struct spi_device *spi);
struct device_driver driver;
};
projects / linux-beck.git / commitdiff