[PATCH 2/2 v2] SPI: spi-pxa2xx: SPI support for Intel Quark X1000
From: Weike Chen
Date: Mon Sep 29 2014 - 02:32:48 EST
There are two SPI controllers exported by PCI subsystem for Intel Quark X1000.
The SPI memory mapped I/O registers supported by Quark are different from
the current implementation, and Quark only supports the registers of 'SSCR0',
'SSCR1', 'SSSR', 'SSDR', and 'DDS_RATE'. This patch is to enable the SPI for
Intel Quark X1000.
This piece of work is derived from Dan O'Donovan's initial work for Intel Quark
X1000 SPI enabling.
Signed-off-by: Weike Chen <alvin.chen@xxxxxxxxx>
---
drivers/spi/spi-pxa2xx-pci.c | 8 ++
drivers/spi/spi-pxa2xx.c | 204 +++++++++++++++++++++++++++++++++++++-----
drivers/spi/spi-pxa2xx.h | 16 ++--
include/linux/pxa2xx_ssp.h | 21 +++++
4 files changed, 224 insertions(+), 25 deletions(-)
diff --git a/drivers/spi/spi-pxa2xx-pci.c b/drivers/spi/spi-pxa2xx-pci.c
index b285294..b888aeb 100644
--- a/drivers/spi/spi-pxa2xx-pci.c
+++ b/drivers/spi/spi-pxa2xx-pci.c
@@ -19,6 +19,7 @@ enum {
PORT_BSW0,
PORT_BSW1,
PORT_BSW2,
+ PORT_QUARK_X1000,
};
struct pxa_spi_info {
@@ -92,6 +93,12 @@ static struct pxa_spi_info spi_info_configs[] = {
.tx_param = &bsw2_tx_param,
.rx_param = &bsw2_rx_param,
},
+ [PORT_QUARK_X1000] = {
+ .type = QUARK_X1000_SSP,
+ .port_id = -1,
+ .num_chipselect = 4,
+ .max_clk_rate = 50000000,
+ },
};
static int pxa2xx_spi_pci_probe(struct pci_dev *dev,
@@ -192,6 +199,7 @@ static void pxa2xx_spi_pci_remove(struct pci_dev *dev)
static const struct pci_device_id pxa2xx_spi_pci_devices[] = {
{ PCI_VDEVICE(INTEL, 0x2e6a), PORT_CE4100 },
+ { PCI_VDEVICE(INTEL, 0x0935), PORT_QUARK_X1000 },
{ PCI_VDEVICE(INTEL, 0x0f0e), PORT_BYT },
{ PCI_VDEVICE(INTEL, 0x228e), PORT_BSW0 },
{ PCI_VDEVICE(INTEL, 0x2290), PORT_BSW1 },
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index e7ff9c5..7efa55e 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -63,10 +63,64 @@ MODULE_ALIAS("platform:pxa2xx-spi");
| SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \
| SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
+#define QUARK_X1000_SSCR1_CHANGE_MASK (QUARK_X1000_SSCR1_STRF \
+ | QUARK_X1000_SSCR1_EFWR \
+ | QUARK_X1000_SSCR1_RFT \
+ | QUARK_X1000_SSCR1_TFT \
+ | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM)
+
#define LPSS_RX_THRESH_DFLT 64
#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)
@@ -80,9 +134,16 @@ static bool is_lpss_ssp(const struct driver_data *drv_data)
return drv_data->ssp_type == LPSS_SSP;
}
+static bool is_quark_x1000_ssp(const struct driver_data *drv_data)
+{
+ return drv_data->ssp_type == QUARK_X1000_SSP;
+}
+
static u32 pxa2xx_spi_get_ssrc1_change_mask(const struct driver_data *drv_data)
{
switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ return QUARK_X1000_SSCR1_CHANGE_MASK;
default:
return SSCR1_CHANGE_MASK;
}
@@ -92,9 +153,12 @@ static u32
pxa2xx_spi_get_rx_default_thre(const struct driver_data *drv_data)
{
switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ return RX_THRESH_QUARK_X1000_DFLT;
default:
return RX_THRESH_DFLT;
}
+
}
static bool pxa2xx_spi_txfifo_full(const struct driver_data *drv_data)
@@ -103,6 +167,9 @@ static bool pxa2xx_spi_txfifo_full(const struct driver_data *drv_data)
u32 mask;
switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ mask = QUARK_X1000_SSSR_TFL_MASK;
+ break;
default:
mask = SSSR_TFL_MASK;
break;
@@ -112,11 +179,14 @@ static bool pxa2xx_spi_txfifo_full(const struct driver_data *drv_data)
}
static void pxa2xx_spi_clear_rx_thre(const struct driver_data *drv_data,
- u32 *sccr1_reg)
+ u32 *sccr1_reg)
{
u32 mask;
switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ mask = QUARK_X1000_SSCR1_RFT;
+ break;
default:
mask = SSCR1_RFT;
break;
@@ -125,9 +195,12 @@ static void pxa2xx_spi_clear_rx_thre(const struct driver_data *drv_data,
}
static void pxa2xx_spi_set_rx_thre(const struct driver_data *drv_data,
- u32 *sccr1_reg, u32 threshold)
+ u32 *sccr1_reg, u32 threshold)
{
switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ *sccr1_reg |= QUARK_X1000_SSCR1_RxTresh(threshold);
+ break;
default:
*sccr1_reg |= SSCR1_RxTresh(threshold);
break;
@@ -138,6 +211,11 @@ static u32 pxa2xx_configure_sscr0(const struct driver_data *drv_data,
u32 clk_div, u8 bits)
{
switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ return clk_div
+ | QUARK_X1000_SSCR0_Motorola
+ | QUARK_X1000_SSCR0_DataSize(bits > 32 ? 8 : bits)
+ | SSCR0_SSE;
default:
return clk_div
| SSCR0_Motorola
@@ -592,7 +670,7 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
rx_thre = bytes_left;
pxa2xx_spi_set_rx_thre(drv_data, &sccr1_reg,
- rx_thre);
+ rx_thre);
}
write_SSCR1(sccr1_reg, reg);
}
@@ -655,6 +733,28 @@ static irqreturn_t ssp_int(int irq, void *dev_id)
return drv_data->transfer_handler(drv_data);
}
+/*
+ * The Quark SPI data sheet gives a table, and for the given 'rate',
+ * the 'dds' and 'clk_div' can be found in the table.
+ */
+static u32 quark_x1000_set_clk_regvals(u32 rate, u32 *dds, u32 *clk_div)
+{
+ 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;
+ }
+ }
+
+ *dds = quark_spi_rate_table[i-1].dds_clk_rate;
+ *clk_div = quark_spi_rate_table[i-1].clk_div;
+
+ return quark_spi_rate_table[i-1].bitrate;
+}
+
static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate)
{
unsigned long ssp_clk = drv_data->max_clk_rate;
@@ -668,6 +768,20 @@ static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate)
return ((ssp_clk / rate - 1) & 0xfff) << 8;
}
+static unsigned int pxa2xx_ssp_get_clk_div(struct driver_data *drv_data,
+ struct chip_data *chip, int rate)
+{
+ u32 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;
+ default:
+ return ssp_get_clk_div(drv_data, rate);
+ }
+}
+
static void pump_transfers(unsigned long data)
{
struct driver_data *drv_data = (struct driver_data *)data;
@@ -770,7 +884,7 @@ static void pump_transfers(unsigned long data)
if (transfer->bits_per_word)
bits = transfer->bits_per_word;
- clk_div = ssp_get_clk_div(drv_data, speed);
+ clk_div = pxa2xx_ssp_get_clk_div(drv_data, chip, speed);
if (bits <= 8) {
drv_data->n_bytes = 1;
@@ -838,6 +952,10 @@ static void pump_transfers(unsigned long data)
write_SSITF(chip->lpss_tx_threshold, reg);
}
+ if (is_quark_x1000_ssp(drv_data) &&
+ (read_DDS_RATE(reg) != chip->dds_rate))
+ write_DDS_RATE(chip->dds_rate, reg);
+
/* see if we need to reload the config registers */
if ((read_SSCR0(reg) != cr0) ||
(read_SSCR1(reg) & change_mask) != (cr1 & change_mask)) {
@@ -941,14 +1059,22 @@ static int setup(struct spi_device *spi)
unsigned int clk_div;
uint tx_thres, tx_hi_thres, rx_thres;
- if (is_lpss_ssp(drv_data)) {
+ switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ tx_thres = TX_THRESH_QUARK_X1000_DFLT;
+ tx_hi_thres = 0;
+ rx_thres = RX_THRESH_QUARK_X1000_DFLT;
+ break;
+ case LPSS_SSP:
tx_thres = LPSS_TX_LOTHRESH_DFLT;
tx_hi_thres = LPSS_TX_HITHRESH_DFLT;
rx_thres = LPSS_RX_THRESH_DFLT;
- } else {
+ break;
+ default:
tx_thres = TX_THRESH_DFLT;
tx_hi_thres = 0;
rx_thres = RX_THRESH_DFLT;
+ break;
}
/* Only alloc on first setup */
@@ -1001,9 +1127,6 @@ static int setup(struct spi_device *spi)
chip->enable_dma = drv_data->master_info->enable_dma;
}
- 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);
@@ -1022,11 +1145,24 @@ static int setup(struct spi_device *spi)
}
}
- clk_div = ssp_get_clk_div(drv_data, spi->max_speed_hz);
+ clk_div = pxa2xx_ssp_get_clk_div(drv_data, chip, spi->max_speed_hz);
chip->speed_hz = spi->max_speed_hz;
chip->cr0 = pxa2xx_configure_sscr0(drv_data, clk_div,
spi->bits_per_word);
+ switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ chip->threshold = (QUARK_X1000_SSCR1_RxTresh(rx_thres)
+ & QUARK_X1000_SSCR1_RFT)
+ | (QUARK_X1000_SSCR1_TxTresh(tx_thres)
+ & QUARK_X1000_SSCR1_TFT);
+ break;
+ default:
+ chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) |
+ (SSCR1_TxTresh(tx_thres) & SSCR1_TFT);
+ break;
+ }
+
chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH);
chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0)
| (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0);
@@ -1055,7 +1191,8 @@ static int setup(struct spi_device *spi)
chip->read = u16_reader;
chip->write = u16_writer;
} else if (spi->bits_per_word <= 32) {
- chip->cr0 |= SSCR0_EDSS;
+ if (!is_quark_x1000_ssp(drv_data))
+ chip->cr0 |= SSCR0_EDSS;
chip->n_bytes = 4;
chip->read = u32_reader;
chip->write = u32_writer;
@@ -1205,7 +1342,15 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
drv_data->ioaddr = ssp->mmio_base;
drv_data->ssdr_physical = ssp->phys_base + SSDR;
if (pxa25x_ssp_comp(drv_data)) {
- master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
+ switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
+ break;
+ default:
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
+ break;
+ }
+
drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE;
drv_data->dma_cr1 = 0;
drv_data->clear_sr = SSSR_ROR;
@@ -1243,16 +1388,35 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
/* Load default SSP configuration */
write_SSCR0(0, drv_data->ioaddr);
- write_SSCR1(SSCR1_RxTresh(RX_THRESH_DFLT) |
- SSCR1_TxTresh(TX_THRESH_DFLT),
- drv_data->ioaddr);
- write_SSCR0(SSCR0_SCR(2)
- | SSCR0_Motorola
- | SSCR0_DataSize(8),
- drv_data->ioaddr);
+ switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ write_SSCR1(QUARK_X1000_SSCR1_RxTresh(
+ RX_THRESH_QUARK_X1000_DFLT) |
+ QUARK_X1000_SSCR1_TxTresh(
+ TX_THRESH_QUARK_X1000_DFLT),
+ drv_data->ioaddr);
+
+ /* using the Motorola SPI protocol and use 8 bit frame */
+ write_SSCR0(QUARK_X1000_SSCR0_Motorola
+ | QUARK_X1000_SSCR0_DataSize(8),
+ drv_data->ioaddr);
+ break;
+ default:
+ write_SSCR1(SSCR1_RxTresh(RX_THRESH_DFLT) |
+ SSCR1_TxTresh(TX_THRESH_DFLT),
+ drv_data->ioaddr);
+ write_SSCR0(SSCR0_SCR(2)
+ | SSCR0_Motorola
+ | SSCR0_DataSize(8),
+ drv_data->ioaddr);
+ break;
+ }
+
if (!pxa25x_ssp_comp(drv_data))
write_SSTO(0, drv_data->ioaddr);
- write_SSPSP(0, drv_data->ioaddr);
+
+ if (!is_quark_x1000_ssp(drv_data))
+ write_SSPSP(0, drv_data->ioaddr);
lpss_ssp_setup(drv_data);
diff --git a/drivers/spi/spi-pxa2xx.h b/drivers/spi/spi-pxa2xx.h
index 5adc2a1..6bec59c 100644
--- a/drivers/spi/spi-pxa2xx.h
+++ b/drivers/spi/spi-pxa2xx.h
@@ -93,6 +93,7 @@ struct driver_data {
struct chip_data {
u32 cr0;
u32 cr1;
+ u32 dds_rate;
u32 psp;
u32 timeout;
u8 n_bytes;
@@ -126,6 +127,7 @@ DEFINE_SSP_REG(SSCR1, 0x04)
DEFINE_SSP_REG(SSSR, 0x08)
DEFINE_SSP_REG(SSITR, 0x0c)
DEFINE_SSP_REG(SSDR, 0x10)
+DEFINE_SSP_REG(DDS_RATE, 0x28) /* DDS Clock Rate */
DEFINE_SSP_REG(SSTO, 0x28)
DEFINE_SSP_REG(SSPSP, 0x2c)
DEFINE_SSP_REG(SSITF, SSITF)
@@ -141,18 +143,22 @@ DEFINE_SSP_REG(SSIRF, SSIRF)
static inline int pxa25x_ssp_comp(struct driver_data *drv_data)
{
- if (drv_data->ssp_type == PXA25x_SSP)
+ switch (drv_data->ssp_type) {
+ case PXA25x_SSP:
+ case CE4100_SSP:
+ case QUARK_X1000_SSP:
return 1;
- if (drv_data->ssp_type == CE4100_SSP)
- return 1;
- return 0;
+ default:
+ return 0;
+ }
}
static inline void write_SSSR_CS(struct driver_data *drv_data, u32 val)
{
void __iomem *reg = drv_data->ioaddr;
- if (drv_data->ssp_type == CE4100_SSP)
+ if (drv_data->ssp_type == CE4100_SSP ||
+ drv_data->ssp_type == QUARK_X1000_SSP)
val |= read_SSSR(reg) & SSSR_ALT_FRM_MASK;
write_SSSR(val, reg);
diff --git a/include/linux/pxa2xx_ssp.h b/include/linux/pxa2xx_ssp.h
index f2b4051..a4668e6 100644
--- a/include/linux/pxa2xx_ssp.h
+++ b/include/linux/pxa2xx_ssp.h
@@ -106,6 +106,26 @@
#define SSCR1_TxTresh(x) (((x) - 1) << 6) /* level [1..4] */
#define SSCR1_RFT (0x00000c00) /* Receive FIFO Threshold (mask) */
#define SSCR1_RxTresh(x) (((x) - 1) << 10) /* level [1..4] */
+
+/* QUARK_X1000 SSCR0 bit definition */
+#define QUARK_X1000_SSCR0_DSS (0x1F) /* Data Size Select (mask) */
+#define QUARK_X1000_SSCR0_DataSize(x) ((x) - 1) /* Data Size Select [4..32] */
+#define QUARK_X1000_SSCR0_FRF (0x3 << 5) /* FRame Format (mask) */
+#define QUARK_X1000_SSCR0_Motorola (0x0 << 5) /* Motorola's Serial Peripheral Interface (SPI) */
+
+#define RX_THRESH_QUARK_X1000_DFLT 1
+#define TX_THRESH_QUARK_X1000_DFLT 16
+
+#define QUARK_X1000_SSSR_TFL_MASK (0x1F << 8) /* Transmit FIFO Level mask */
+#define QUARK_X1000_SSSR_RFL_MASK (0x1F << 13) /* Receive FIFO Level mask */
+
+#define QUARK_X1000_SSCR1_TFT (0x1F << 6) /* Transmit FIFO Threshold (mask) */
+#define QUARK_X1000_SSCR1_TxTresh(x) (((x) - 1) << 6) /* level [1..32] */
+#define QUARK_X1000_SSCR1_RFT (0x1F << 11) /* Receive FIFO Threshold (mask) */
+#define QUARK_X1000_SSCR1_RxTresh(x) (((x) - 1) << 11) /* level [1..32] */
+#define QUARK_X1000_SSCR1_STRF (1 << 17) /* Select FIFO or EFWR */
+#define QUARK_X1000_SSCR1_EFWR (1 << 16) /* Enable FIFO Write/Read */
+
#endif
/* extra bits in PXA255, PXA26x and PXA27x SSP ports */
@@ -175,6 +195,7 @@ enum pxa_ssp_type {
PXA910_SSP,
CE4100_SSP,
LPSS_SSP,
+ QUARK_X1000_SSP,
};
struct ssp_device {
--
1.7.9.5
--
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