These register reads and writes are sometimes directly next to each other in the register address space. Let's use regmap bulk read/write APIs to get the data with one transfer instead of multiple i2c transfers. This helps cut down on the number of transfers in the case of something like reading an EDID where we read in blocks of 16 bytes at a time and the last for loop here is sending an i2c transfer for each of those 16 bytes, one at a time. Ouch!
Changes in v3: - Undid changes in v2
Changes in v2: - Combined AUX_CMD register write
Reviewed-by: Douglas Anderson dianders@chromium.org Cc: Laurent Pinchart Laurent.pinchart@ideasonboard.com Cc: Jonas Karlman jonas@kwiboo.se Cc: Jernej Skrabec jernej.skrabec@siol.net Cc: Sean Paul seanpaul@chromium.org Acked-by: Sam Ravnborg sam@ravnborg.org Signed-off-by: Stephen Boyd swboyd@chromium.org --- drivers/gpu/drm/bridge/ti-sn65dsi86.c | 50 ++++++++++++--------------- 1 file changed, 22 insertions(+), 28 deletions(-)
diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi86.c b/drivers/gpu/drm/bridge/ti-sn65dsi86.c index ecdf9b01340f..87726b9e446f 100644 --- a/drivers/gpu/drm/bridge/ti-sn65dsi86.c +++ b/drivers/gpu/drm/bridge/ti-sn65dsi86.c @@ -17,6 +17,8 @@ #include <linux/regmap.h> #include <linux/regulator/consumer.h>
+#include <asm/unaligned.h> + #include <drm/drm_atomic.h> #include <drm/drm_atomic_helper.h> #include <drm/drm_bridge.h> @@ -72,6 +74,7 @@ #define SN_AUX_ADDR_19_16_REG 0x74 #define SN_AUX_ADDR_15_8_REG 0x75 #define SN_AUX_ADDR_7_0_REG 0x76 +#define SN_AUX_ADDR_MASK GENMASK(19, 0) #define SN_AUX_LENGTH_REG 0x77 #define SN_AUX_CMD_REG 0x78 #define AUX_CMD_SEND BIT(0) @@ -841,11 +844,13 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux, struct ti_sn_bridge *pdata = aux_to_ti_sn_bridge(aux); u32 request = msg->request & ~DP_AUX_I2C_MOT; u32 request_val = AUX_CMD_REQ(msg->request); - u8 *buf = (u8 *)msg->buffer; + u8 *buf = msg->buffer; + unsigned int len = msg->size; unsigned int val; - int ret, i; + int ret; + u8 addr_len[SN_AUX_LENGTH_REG + 1 - SN_AUX_ADDR_19_16_REG];
- if (msg->size > SN_AUX_MAX_PAYLOAD_BYTES) + if (len > SN_AUX_MAX_PAYLOAD_BYTES) return -EINVAL;
switch (request) { @@ -859,19 +864,14 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux, return -EINVAL; }
- regmap_write(pdata->regmap, SN_AUX_ADDR_19_16_REG, - (msg->address >> 16) & 0xF); - regmap_write(pdata->regmap, SN_AUX_ADDR_15_8_REG, - (msg->address >> 8) & 0xFF); - regmap_write(pdata->regmap, SN_AUX_ADDR_7_0_REG, msg->address & 0xFF); - - regmap_write(pdata->regmap, SN_AUX_LENGTH_REG, msg->size); + BUILD_BUG_ON(sizeof(addr_len) != sizeof(__be32)); + put_unaligned_be32((msg->address & SN_AUX_ADDR_MASK) << 8 | len, + addr_len); + regmap_bulk_write(pdata->regmap, SN_AUX_ADDR_19_16_REG, addr_len, + ARRAY_SIZE(addr_len));
- if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE) { - for (i = 0; i < msg->size; i++) - regmap_write(pdata->regmap, SN_AUX_WDATA_REG(i), - buf[i]); - } + if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE) + regmap_bulk_write(pdata->regmap, SN_AUX_WDATA_REG(0), buf, len);
/* Clear old status bits before start so we don't get confused */ regmap_write(pdata->regmap, SN_AUX_CMD_STATUS_REG, @@ -895,21 +895,15 @@ static ssize_t ti_sn_aux_transfer(struct drm_dp_aux *aux, || (val & AUX_IRQ_STATUS_AUX_SHORT)) return -ENXIO;
- if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE) - return msg->size; + if (request == DP_AUX_NATIVE_WRITE || request == DP_AUX_I2C_WRITE || + len == 0) + return len;
- for (i = 0; i < msg->size; i++) { - unsigned int val; - ret = regmap_read(pdata->regmap, SN_AUX_RDATA_REG(i), - &val); - if (ret) - return ret; - - WARN_ON(val & ~0xFF); - buf[i] = (u8)(val & 0xFF); - } + ret = regmap_bulk_read(pdata->regmap, SN_AUX_RDATA_REG(0), buf, len); + if (ret) + return ret;
- return msg->size; + return len; }
static int ti_sn_bridge_parse_dsi_host(struct ti_sn_bridge *pdata)