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phy: dphy: add support to calculate the timing based on hs_clk_rate

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For MIPI-CSI sender use-case it is common to specify the allowed
link-frequencies which should be used for the MIPI link and is
half the hs-clock rate.

This commit adds a helper to calculate the D-PHY timing based on the
hs-clock rate so we don't need to calculate the timings within the
driver.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
This commit is contained in:
Marco Felsch 2022-09-30 14:48:10 +02:00 committed by Sakari Ailus
parent 7afa5db0ea
commit 22168675ba
2 changed files with 21 additions and 4 deletions
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22
drivers/phy/phy-core-mipi-dphy.c
View File

@ -20,16 +20,18 @@
static int phy_mipi_dphy_calc_config(unsigned long pixel_clock,
unsigned int bpp,
unsigned int lanes,
unsigned long long hs_clk_rate,
struct phy_configure_opts_mipi_dphy *cfg)
{
unsigned long long hs_clk_rate;
unsigned long long ui;
if (!cfg)
return -EINVAL;
hs_clk_rate = pixel_clock * bpp;
do_div(hs_clk_rate, lanes);
if (!hs_clk_rate) {
hs_clk_rate = pixel_clock * bpp;
do_div(hs_clk_rate, lanes);
}
ui = ALIGN(PSEC_PER_SEC, hs_clk_rate);
do_div(ui, hs_clk_rate);
@ -81,11 +83,23 @@ int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
unsigned int lanes,
struct phy_configure_opts_mipi_dphy *cfg)
{
return phy_mipi_dphy_calc_config(pixel_clock, bpp, lanes, cfg);
return phy_mipi_dphy_calc_config(pixel_clock, bpp, lanes, 0, cfg);
}
EXPORT_SYMBOL(phy_mipi_dphy_get_default_config);
int phy_mipi_dphy_get_default_config_for_hsclk(unsigned long long hs_clk_rate,
unsigned int lanes,
struct phy_configure_opts_mipi_dphy *cfg)
{
if (!hs_clk_rate)
return -EINVAL;
return phy_mipi_dphy_calc_config(0, 0, lanes, hs_clk_rate, cfg);
}
EXPORT_SYMBOL(phy_mipi_dphy_get_default_config_for_hsclk);
/*
* Validate D-PHY configuration according to MIPI D-PHY specification
* (v1.2, Section Section 6.9 "Global Operation Timing Parameters").

3
include/linux/phy/phy-mipi-dphy.h
View File

@ -279,6 +279,9 @@ int phy_mipi_dphy_get_default_config(unsigned long pixel_clock,
unsigned int bpp,
unsigned int lanes,
struct phy_configure_opts_mipi_dphy *cfg);
int phy_mipi_dphy_get_default_config_for_hsclk(unsigned long long hs_clk_rate,
unsigned int lanes,
struct phy_configure_opts_mipi_dphy *cfg);
int phy_mipi_dphy_config_validate(struct phy_configure_opts_mipi_dphy *cfg);
#endif /* __PHY_MIPI_DPHY_H_ */