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path: root/drivers/spi/spi-omap2-mcspi.c
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Diffstat (limited to 'drivers/spi/spi-omap2-mcspi.c')
-rw-r--r--drivers/spi/spi-omap2-mcspi.c65
1 files changed, 44 insertions, 21 deletions
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index a72127f08e39..2941c5b96ebc 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -22,7 +22,6 @@
*/
#include <linux/kernel.h>
-#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/device.h>
@@ -45,6 +44,7 @@
#include <linux/platform_data/spi-omap2-mcspi.h>
#define OMAP2_MCSPI_MAX_FREQ 48000000
+#define OMAP2_MCSPI_MAX_DIVIDER 4096
#define OMAP2_MCSPI_MAX_FIFODEPTH 64
#define OMAP2_MCSPI_MAX_FIFOWCNT 0xFFFF
#define SPI_AUTOSUSPEND_TIMEOUT 2000
@@ -89,6 +89,7 @@
#define OMAP2_MCSPI_CHCONF_FORCE BIT(20)
#define OMAP2_MCSPI_CHCONF_FFET BIT(27)
#define OMAP2_MCSPI_CHCONF_FFER BIT(28)
+#define OMAP2_MCSPI_CHCONF_CLKG BIT(29)
#define OMAP2_MCSPI_CHSTAT_RXS BIT(0)
#define OMAP2_MCSPI_CHSTAT_TXS BIT(1)
@@ -96,6 +97,7 @@
#define OMAP2_MCSPI_CHSTAT_TXFFE BIT(3)
#define OMAP2_MCSPI_CHCTRL_EN BIT(0)
+#define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK (0xff << 8)
#define OMAP2_MCSPI_WAKEUPENABLE_WKEN BIT(0)
@@ -149,7 +151,7 @@ struct omap2_mcspi_cs {
int word_len;
struct list_head node;
/* Context save and restore shadow register */
- u32 chconf0;
+ u32 chconf0, chctrl0;
};
static inline void mcspi_write_reg(struct spi_master *master,
@@ -230,10 +232,16 @@ static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
{
+ struct omap2_mcspi_cs *cs = spi->controller_state;
u32 l;
- l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
- mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
+ l = cs->chctrl0;
+ if (enable)
+ l |= OMAP2_MCSPI_CHCTRL_EN;
+ else
+ l &= ~OMAP2_MCSPI_CHCTRL_EN;
+ cs->chctrl0 = l;
+ mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
/* Flash post-writes */
mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
}
@@ -840,7 +848,7 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
struct omap2_mcspi_cs *cs = spi->controller_state;
struct omap2_mcspi *mcspi;
struct spi_master *spi_cntrl;
- u32 l = 0, div = 0;
+ u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
u8 word_len = spi->bits_per_word;
u32 speed_hz = spi->max_speed_hz;
@@ -856,7 +864,17 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
speed_hz = t->speed_hz;
speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
- div = omap2_mcspi_calc_divisor(speed_hz);
+ if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
+ clkd = omap2_mcspi_calc_divisor(speed_hz);
+ speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
+ clkg = 0;
+ } else {
+ div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
+ speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
+ clkd = (div - 1) & 0xf;
+ extclk = (div - 1) >> 4;
+ clkg = OMAP2_MCSPI_CHCONF_CLKG;
+ }
l = mcspi_cached_chconf0(spi);
@@ -885,7 +903,16 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
/* set clock divisor */
l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
- l |= div << 2;
+ l |= clkd << 2;
+
+ /* set clock granularity */
+ l &= ~OMAP2_MCSPI_CHCONF_CLKG;
+ l |= clkg;
+ if (clkg) {
+ cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
+ cs->chctrl0 |= extclk << 8;
+ mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
+ }
/* set SPI mode 0..3 */
if (spi->mode & SPI_CPOL)
@@ -900,7 +927,7 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,
mcspi_write_chconf0(spi, l);
dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
- OMAP2_MCSPI_MAX_FREQ >> div,
+ speed_hz,
(spi->mode & SPI_CPHA) ? "trailing" : "leading",
(spi->mode & SPI_CPOL) ? "inverted" : "normal");
@@ -972,6 +999,7 @@ static int omap2_mcspi_setup(struct spi_device *spi)
cs->base = mcspi->base + spi->chip_select * 0x14;
cs->phys = mcspi->phys + spi->chip_select * 0x14;
cs->chconf0 = 0;
+ cs->chctrl0 = 0;
spi->controller_state = cs;
/* Link this to context save list */
list_add_tail(&cs->node, &ctx->cs);
@@ -1057,12 +1085,15 @@ static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m)
status = -EINVAL;
break;
}
- if (par_override || t->speed_hz || t->bits_per_word) {
+ if (par_override ||
+ (t->speed_hz != spi->max_speed_hz) ||
+ (t->bits_per_word != spi->bits_per_word)) {
par_override = 1;
status = omap2_mcspi_setup_transfer(spi, t);
if (status < 0)
break;
- if (!t->speed_hz && !t->bits_per_word)
+ if (t->speed_hz == spi->max_speed_hz &&
+ t->bits_per_word == spi->bits_per_word)
par_override = 0;
}
if (cd && cd->cs_per_word) {
@@ -1176,16 +1207,12 @@ static int omap2_mcspi_transfer_one_message(struct spi_master *master,
m->actual_length = 0;
m->status = 0;
- /* reject invalid messages and transfers */
- if (list_empty(&m->transfers))
- return -EINVAL;
list_for_each_entry(t, &m->transfers, transfer_list) {
const void *tx_buf = t->tx_buf;
void *rx_buf = t->rx_buf;
unsigned len = t->len;
- if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
- || (len && !(rx_buf || tx_buf))) {
+ if ((len && !(rx_buf || tx_buf))) {
dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
t->speed_hz,
len,
@@ -1194,12 +1221,6 @@ static int omap2_mcspi_transfer_one_message(struct spi_master *master,
t->bits_per_word);
return -EINVAL;
}
- if (t->speed_hz && t->speed_hz < (OMAP2_MCSPI_MAX_FREQ >> 15)) {
- dev_dbg(mcspi->dev, "speed_hz %d below minimum %d Hz\n",
- t->speed_hz,
- OMAP2_MCSPI_MAX_FREQ >> 15);
- return -EINVAL;
- }
if (m->is_dma_mapped || len < DMA_MIN_BYTES)
continue;
@@ -1311,6 +1332,8 @@ static int omap2_mcspi_probe(struct platform_device *pdev)
master->transfer_one_message = omap2_mcspi_transfer_one_message;
master->cleanup = omap2_mcspi_cleanup;
master->dev.of_node = node;
+ master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
+ master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
platform_set_drvdata(pdev, master);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-16 11:23:25 +0000