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-rw-r--r--drivers/spi/spi-pxa2xx.c133
-rw-r--r--drivers/spi/spi-pxa2xx.h6
-rw-r--r--include/linux/pxa2xx_ssp.h9
-rw-r--r--include/linux/spi/pxa2xx_spi.h1
4 files changed, 145 insertions, 4 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 8a5ba0aa095..4bd6b729f71 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1,5 +1,6 @@
/*
* Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
+ * Copyright (C) 2013, Intel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -61,6 +62,98 @@ MODULE_ALIAS("platform:pxa2xx-spi");
| SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
| SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
+#define LPSS_RX_THRESH_DFLT 64
+#define LPSS_TX_LOTHRESH_DFLT 160
+#define LPSS_TX_HITHRESH_DFLT 224
+
+/* Offset from drv_data->lpss_base */
+#define SPI_CS_CONTROL 0x18
+#define SPI_CS_CONTROL_SW_MODE BIT(0)
+#define SPI_CS_CONTROL_CS_HIGH BIT(1)
+
+static bool is_lpss_ssp(const struct driver_data *drv_data)
+{
+ return drv_data->ssp_type == LPSS_SSP;
+}
+
+/*
+ * Read and write LPSS SSP private registers. Caller must first check that
+ * is_lpss_ssp() returns true before these can be called.
+ */
+static u32 __lpss_ssp_read_priv(struct driver_data *drv_data, unsigned offset)
+{
+ WARN_ON(!drv_data->lpss_base);
+ return readl(drv_data->lpss_base + offset);
+}
+
+static void __lpss_ssp_write_priv(struct driver_data *drv_data,
+ unsigned offset, u32 value)
+{
+ WARN_ON(!drv_data->lpss_base);
+ writel(value, drv_data->lpss_base + offset);
+}
+
+/*
+ * lpss_ssp_setup - perform LPSS SSP specific setup
+ * @drv_data: pointer to the driver private data
+ *
+ * Perform LPSS SSP specific setup. This function must be called first if
+ * one is going to use LPSS SSP private registers.
+ */
+static void lpss_ssp_setup(struct driver_data *drv_data)
+{
+ unsigned offset = 0x400;
+ u32 value, orig;
+
+ if (!is_lpss_ssp(drv_data))
+ return;
+
+ /*
+ * Perform auto-detection of the LPSS SSP private registers. They
+ * can be either at 1k or 2k offset from the base address.
+ */
+ orig = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
+
+ value = orig | SPI_CS_CONTROL_SW_MODE;
+ writel(value, drv_data->ioaddr + offset + SPI_CS_CONTROL);
+ value = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
+ if (value != (orig | SPI_CS_CONTROL_SW_MODE)) {
+ offset = 0x800;
+ goto detection_done;
+ }
+
+ value &= ~SPI_CS_CONTROL_SW_MODE;
+ writel(value, drv_data->ioaddr + offset + SPI_CS_CONTROL);
+ value = readl(drv_data->ioaddr + offset + SPI_CS_CONTROL);
+ if (value != orig) {
+ offset = 0x800;
+ goto detection_done;
+ }
+
+detection_done:
+ /* Now set the LPSS base */
+ drv_data->lpss_base = drv_data->ioaddr + offset;
+
+ /* Enable software chip select control */
+ value = SPI_CS_CONTROL_SW_MODE | SPI_CS_CONTROL_CS_HIGH;
+ __lpss_ssp_write_priv(drv_data, SPI_CS_CONTROL, value);
+}
+
+static void lpss_ssp_cs_control(struct driver_data *drv_data, bool enable)
+{
+ u32 value;
+
+ if (!is_lpss_ssp(drv_data))
+ return;
+
+ value = __lpss_ssp_read_priv(drv_data, SPI_CS_CONTROL);
+ if (enable)
+ value &= ~SPI_CS_CONTROL_CS_HIGH;
+ else
+ value |= SPI_CS_CONTROL_CS_HIGH;
+ __lpss_ssp_write_priv(drv_data, SPI_CS_CONTROL, value);
+}
+
static void cs_assert(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
@@ -75,8 +168,12 @@ static void cs_assert(struct driver_data *drv_data)
return;
}
- if (gpio_is_valid(chip->gpio_cs))
+ if (gpio_is_valid(chip->gpio_cs)) {
gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
+ return;
+ }
+
+ lpss_ssp_cs_control(drv_data, true);
}
static void cs_deassert(struct driver_data *drv_data)
@@ -91,8 +188,12 @@ static void cs_deassert(struct driver_data *drv_data)
return;
}
- if (gpio_is_valid(chip->gpio_cs))
+ if (gpio_is_valid(chip->gpio_cs)) {
gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted);
+ return;
+ }
+
+ lpss_ssp_cs_control(drv_data, false);
}
int pxa2xx_spi_flush(struct driver_data *drv_data)
@@ -642,6 +743,13 @@ static void pump_transfers(unsigned long data)
write_SSSR_CS(drv_data, drv_data->clear_sr);
}
+ if (is_lpss_ssp(drv_data)) {
+ if ((read_SSIRF(reg) & 0xff) != chip->lpss_rx_threshold)
+ write_SSIRF(chip->lpss_rx_threshold, reg);
+ if ((read_SSITF(reg) & 0xffff) != chip->lpss_tx_threshold)
+ write_SSITF(chip->lpss_tx_threshold, reg);
+ }
+
/* see if we need to reload the config registers */
if ((read_SSCR0(reg) != cr0)
|| (read_SSCR1(reg) & SSCR1_CHANGE_MASK) !=
@@ -754,8 +862,17 @@ static int setup(struct spi_device *spi)
struct chip_data *chip;
struct driver_data *drv_data = spi_master_get_devdata(spi->master);
unsigned int clk_div;
- uint tx_thres = TX_THRESH_DFLT;
- uint rx_thres = RX_THRESH_DFLT;
+ uint tx_thres, tx_hi_thres, rx_thres;
+
+ if (is_lpss_ssp(drv_data)) {
+ tx_thres = LPSS_TX_LOTHRESH_DFLT;
+ tx_hi_thres = LPSS_TX_HITHRESH_DFLT;
+ rx_thres = LPSS_RX_THRESH_DFLT;
+ } else {
+ tx_thres = TX_THRESH_DFLT;
+ tx_hi_thres = 0;
+ rx_thres = RX_THRESH_DFLT;
+ }
if (!pxa25x_ssp_comp(drv_data)
&& (spi->bits_per_word < 4 || spi->bits_per_word > 32)) {
@@ -808,6 +925,8 @@ static int setup(struct spi_device *spi)
chip->timeout = chip_info->timeout;
if (chip_info->tx_threshold)
tx_thres = chip_info->tx_threshold;
+ if (chip_info->tx_hi_threshold)
+ tx_hi_thres = chip_info->tx_hi_threshold;
if (chip_info->rx_threshold)
rx_thres = chip_info->rx_threshold;
chip->enable_dma = drv_data->master_info->enable_dma;
@@ -819,6 +938,10 @@ static int setup(struct spi_device *spi)
chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
(SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
+ chip->lpss_rx_threshold = SSIRF_RxThresh(rx_thres);
+ chip->lpss_tx_threshold = SSITF_TxLoThresh(tx_thres)
+ | SSITF_TxHiThresh(tx_hi_thres);
+
/* set dma burst and threshold outside of chip_info path so that if
* chip_info goes away after setting chip->enable_dma, the
* burst and threshold can still respond to changes in bits_per_word */
@@ -1006,6 +1129,8 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
write_SSTO(0, drv_data->ioaddr);
write_SSPSP(0, drv_data->ioaddr);
+ lpss_ssp_setup(drv_data);
+
tasklet_init(&drv_data->pump_transfers, pump_transfers,
(unsigned long)drv_data);
diff --git a/drivers/spi/spi-pxa2xx.h b/drivers/spi/spi-pxa2xx.h
index 97ff4717e6a..5adc2a11c7b 100644
--- a/drivers/spi/spi-pxa2xx.h
+++ b/drivers/spi/spi-pxa2xx.h
@@ -86,6 +86,8 @@ struct driver_data {
int (*read)(struct driver_data *drv_data);
irqreturn_t (*transfer_handler)(struct driver_data *drv_data);
void (*cs_control)(u32 command);
+
+ void __iomem *lpss_base;
};
struct chip_data {
@@ -97,6 +99,8 @@ struct chip_data {
u32 dma_burst_size;
u32 threshold;
u32 dma_threshold;
+ u16 lpss_rx_threshold;
+ u16 lpss_tx_threshold;
u8 enable_dma;
u8 bits_per_word;
u32 speed_hz;
@@ -124,6 +128,8 @@ DEFINE_SSP_REG(SSITR, 0x0c)
DEFINE_SSP_REG(SSDR, 0x10)
DEFINE_SSP_REG(SSTO, 0x28)
DEFINE_SSP_REG(SSPSP, 0x2c)
+DEFINE_SSP_REG(SSITF, SSITF)
+DEFINE_SSP_REG(SSIRF, SSIRF)
#define START_STATE ((void *)0)
#define RUNNING_STATE ((void *)1)
diff --git a/include/linux/pxa2xx_ssp.h b/include/linux/pxa2xx_ssp.h
index 065e7f6c3ad..467cc6307b6 100644
--- a/include/linux/pxa2xx_ssp.h
+++ b/include/linux/pxa2xx_ssp.h
@@ -155,6 +155,14 @@
#define SSACD_ACDS(x) ((x) << 0) /* Audio clock divider select */
#define SSACD_SCDX8 (1 << 7) /* SYSCLK division ratio select */
+/* LPSS SSP */
+#define SSITF 0x44 /* TX FIFO trigger level */
+#define SSITF_TxLoThresh(x) (((x) - 1) << 8)
+#define SSITF_TxHiThresh(x) ((x) - 1)
+
+#define SSIRF 0x48 /* RX FIFO trigger level */
+#define SSIRF_RxThresh(x) ((x) - 1)
+
enum pxa_ssp_type {
SSP_UNDEFINED = 0,
PXA25x_SSP, /* pxa 210, 250, 255, 26x */
@@ -164,6 +172,7 @@ enum pxa_ssp_type {
PXA168_SSP,
PXA910_SSP,
CE4100_SSP,
+ LPSS_SSP,
};
struct ssp_device {
diff --git a/include/linux/spi/pxa2xx_spi.h b/include/linux/spi/pxa2xx_spi.h
index e5cbbc4c57f..82d5111cd0c 100644
--- a/include/linux/spi/pxa2xx_spi.h
+++ b/include/linux/spi/pxa2xx_spi.h
@@ -44,6 +44,7 @@ struct pxa2xx_spi_master {
*/
struct pxa2xx_spi_chip {
u8 tx_threshold;
+ u8 tx_hi_threshold;
u8 rx_threshold;
u8 dma_burst_size;
u32 timeout;
generated by cgit v1.2.3-70-g09d2 (git 2.51.2) at 2025-11-04 15:00:23 +0000