[PATCH 8/8] intel_mid_ssp_spi: Implement slave side quirk

From: Alan Cox
Date: Wed Feb 09 2011 - 05:38:34 EST


From: Alan Cox <alan@xxxxxxxxxxxxxxx>

Signed-off-by: Alan Cox <alan@xxxxxxxxxxxxxxx>
---

drivers/spi/intel_mid_ssp_spi.c | 32 +++++++++++++++++++++-----------
1 files changed, 21 insertions(+), 11 deletions(-)


diff --git a/drivers/spi/intel_mid_ssp_spi.c b/drivers/spi/intel_mid_ssp_spi.c
index 8d7a157..91976af 100644
--- a/drivers/spi/intel_mid_ssp_spi.c
+++ b/drivers/spi/intel_mid_ssp_spi.c
@@ -93,15 +93,13 @@ MODULE_LICENSE("GPL");

#define PNWL_CR1_MASTER_ROLE 0
#define PNWL_CR1_SLAVE_ROLE (SSCR1_SFRMDIR | SSCR1_SCLKDIR)
-/* MRST SSP must be slave */
-#define PNWL_CR1_ROLE PNWL_CR1_MASTER_ROLE
-#define PNWL_CR1(spi, chip) \
+#define PNWL_CR1(spi, chip, role) \
((chip->enable_loopback ? SSCR1_LBM : 0) | \
((spi->mode & SPI_CPHA) ? SSCR1_SPH : 0) | \
((spi->mode & SPI_CPOL) ? SSCR1_SPO : 0) | \
SSCR1_SCFR | \
chip->threshold | \
- PNWL_CR1_ROLE)
+ role)



@@ -603,7 +601,7 @@ free_rxchan:
dma_release_channel(drv_data->rxchan);
if (drv_data->quirks & QUIRKS_SRAM_ADDITIONAL_CPY)
intel_mid_ssp_spi_unmap_sram(drv_data);
-
+
err_exit:
dev_err(&drv_data->pdev->dev, "DMA RX Channel Not available");
pci_dev_put(drv_data->dmac1);
@@ -1203,6 +1201,7 @@ static int setup(struct spi_device *spi)
uint rx_thres = RX_THRESH_DFLT;
u32 clk_div;
struct driver_data *drv_data = spi_master_get_devdata(spi->master);
+ int role = PNWL_CR1_MASTER_ROLE;

if (drv_data->pwrstate == PWRSTATE_OFF) {
dev_dbg(&drv_data->pdev->dev, "setup: busy, pwrstate:%d",
@@ -1272,15 +1271,20 @@ static int setup(struct spi_device *spi)
set_dma_width(drv_data, spi->bits_per_word);
}

- chip->speed_hz = spi->max_speed_hz;
- clk_div = ssp_get_clk_div(chip->speed_hz);
+ if (drv_data->quirks & QUIRKS_SPI_SLAVE_CLOCK_MODE) {
+ role = PNWL_CR1_SLAVE_ROLE;
+ clk_div = 1;
+ } else {
+ chip->speed_hz = spi->max_speed_hz;
+ clk_div = ssp_get_clk_div(chip->speed_hz);
+ }

chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
(SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
chip->bits_per_word = spi->bits_per_word;

chip->cr0 = PNWL_CR0(clk_div, spi->bits_per_word, spi, chip);
- chip->cr1 = PNWL_CR1(spi, chip);
+ chip->cr1 = PNWL_CR1(spi, chip, role);

dev_dbg(&spi->dev,
"KHz:%d bpw:%d mode:%d dma:%d poll:%d loop:%d cr0:%x cr1:%x",
@@ -1340,13 +1344,11 @@ static int intel_mid_ssp_spi_probe(struct pci_dev *pdev,
dev_info(dev, "No Vendor Specific PCI capability");
goto err_abort_probe;
}
- if ((SSP_CFG_GET_MODE(ssp_cfg) != SSP_CFG_SPI_MODE_ID) ||
- SSP_CFG_IS_SPI_SLAVE(ssp_cfg)) {
+ if (SSP_CFG_GET_MODE(ssp_cfg) != SSP_CFG_SPI_MODE_ID) {
dev_info(dev, "Unsupported SSP mode (%02xh)",
ssp_cfg);
goto err_abort_probe;
}
-
dev_info(&pdev->dev, "found PCI SSP controller(ID: %04xh:%04xh"
" cfg: %02xh)", pdev->vendor, pdev->device, ssp_cfg);

@@ -1371,6 +1373,14 @@ static int intel_mid_ssp_spi_probe(struct pci_dev *pdev,
drv_data->wq = create_workqueue(DRIVER_NAME);
INIT_WORK(&drv_data->resume_transfer_work, resume_transfer_work);

+ if (SSP_CFG_IS_SPI_SLAVE(ssp_cfg)) {
+ dev_warn(dev, "Slave clock mode is experimental");
+ drv_data->quirks |= QUIRKS_SPI_SLAVE_CLOCK_MODE;
+ if (drv_data->quirks & QUIRKS_PLATFORM_MRST)
+ drv_data->quirks |= QUIRKS_USE_PM_QOS |
+ QUIRKS_SRAM_ADDITIONAL_CPY;
+ }
+
master->mode_bits = SPI_CPOL | SPI_CPHA;
master->bus_num = SSP_CFG_GET_SPI_BUS_NB(ssp_cfg);
master->num_chipselect = 1;

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