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authorWeike Chen <alvin.chen@intel.com>2014-11-26 02:35:10 -0800
committerMark Brown <broonie@kernel.org>2014-11-26 18:07:45 +0000
commite5262d0568dc9e10de79a726dfd7edb712a2c10b (patch)
treefb8cd4ca58e8f0ef1b1a016ac88139401ed55cfe /drivers/spi/spi-pxa2xx.c
parent4fdb2424cc4499237197a8c9d35b34d68c750475 (diff)
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spi: spi-pxa2xx: SPI support for Intel Quark X1000
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. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Weike Chen <alvin.chen@intel.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-pxa2xx.c')
-rw-r--r--drivers/spi/spi-pxa2xx.c197
1 files changed, 180 insertions, 17 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index d4d29c594156..1a1df5092aca 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;
}
@@ -92,6 +153,8 @@ 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;
}
@@ -103,6 +166,9 @@ 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;
@@ -117,6 +183,9 @@ static void pxa2xx_spi_clear_rx_thre(const struct driver_data *drv_data,
u32 mask;
switch (drv_data->ssp_type) {
+ case QUARK_X1000_SSP:
+ mask = QUARK_X1000_SSCR1_RFT;
+ break;
default:
mask = SSCR1_RFT;
break;
@@ -128,6 +197,9 @@ static void pxa2xx_spi_set_rx_thre(const struct driver_data *drv_data,
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 +210,11 @@ 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
@@ -654,6 +731,28 @@ 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;
@@ -667,6 +766,20 @@ 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;
@@ -769,7 +882,7 @@ 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;
@@ -837,6 +950,10 @@ 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)) {
@@ -940,14 +1057,22 @@ 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 */
@@ -1000,9 +1125,6 @@ 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);
@@ -1021,11 +1143,24 @@ 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);
@@ -1054,7 +1189,8 @@ 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 +1341,15 @@ 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 +1387,35 @@ 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);