spi_qsd: Add vote for clock path
Currently the spi driver votes for its core clock. However, it is
possible that the core-clock's source will be off. When the source
is off, the spi core is not clocked. This patch adds voting for
the entire clock path, thus guarantee clocking to the spi core.
Voting for the path cost a few msecs. A client may choose when
to pay this overhead. By default the votes takes place in the
runtime-pm callbacks which tie to transaction requests. A client
may choose to invoke these callbacks itself whenever it likes
by directly calling the driver's runtime-pm. A third option is
to set the active_only flag in platform data which results in the
callbacks being called when the application processor power state
changes.
CRs-Fixed: 478465
Change-Id: Ib866399c0e84a875a19a0d1506d77bbe77d5fe61
Signed-off-by: Gilad Avidov <gavidov@codeaurora.org>
diff --git a/drivers/spi/spi_qsd.h b/drivers/spi/spi_qsd.h
index b749cc0..672d9e7 100644
--- a/drivers/spi/spi_qsd.h
+++ b/drivers/spi/spi_qsd.h
@@ -167,6 +167,13 @@
#define SPI_BAM_MAX_DESC_NUM 32
#define SPI_MAX_TRFR_BTWN_RESETS ((64 * 1024) - 16) /* 64KB - 16byte */
+enum msm_spi_clk_path_vec_idx {
+ MSM_SPI_CLK_PATH_SUSPEND_VEC = 0,
+ MSM_SPI_CLK_PATH_RESUME_VEC = 1,
+};
+#define MSM_SPI_CLK_PATH_AVRG_BW(dd) (dd->pdata->max_clock_speed * 8)
+#define MSM_SPI_CLK_PATH_BRST_BW(dd) (dd->pdata->max_clock_speed * 8)
+
static char const * const spi_rsrcs[] = {
"spi_clk",
"spi_miso",
@@ -247,6 +254,22 @@
};
#endif
+/**
+ * qup_i2c_clk_path_vote: data to use bus scaling driver for clock path vote
+ *
+ * @client_hdl when zero, client is not registered with the bus scaling driver,
+ * and bus scaling functionality should not be used. When non zero, it
+ * is a bus scaling client id and may be used to vote for clock path.
+ * @reg_err when true, registration error was detected and an error message was
+ * logged. i2c will attempt to re-register but will log error only once.
+ * once registration succeed, the flag is set to false.
+ */
+struct qup_i2c_clk_path_vote {
+ u32 client_hdl;
+ struct msm_bus_scale_pdata *pdata;
+ bool reg_err;
+};
+
struct msm_spi_bam_pipe {
struct sps_pipe *handle;
struct sps_connect config;
@@ -278,6 +301,7 @@
struct completion transfer_complete;
struct clk *clk; /* core clock */
struct clk *pclk; /* interface clock */
+ struct qup_i2c_clk_path_vote clk_path_vote;
unsigned long mem_phys_addr;
size_t mem_size;
int input_fifo_size;