[PATCH v3 3/8] drm/msm/dsi: 28nm PHY: Get ref clock from the DT

Matthias Kaehlcke
2018-12-01T00:54:00Z

Get the ref clock of the PHY from the device tree instead of
hardcoding its name and rate. Use default values if the ref
clock is not specified.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
---
Changes in v3:
- use default name and rate if the ref clock is not specified
in the DT
- store vco_ref_clk_name instead of vco_ref_clk
- dsi_pll_28nm_clk_set_rate: changed data type of ref_clk_rate to
unsigned long
- fixed check for EPROBE_DEFER
- renamed VCO_REF_CLK_RATE to VCO_REF_CLK_DEFAULT_RATE

Changes in v2:
- patch added to the series
---
drivers/gpu/drm/msm/dsi/pll/dsi_pll_28nm.c | 35 ++++++++++++++++------
1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_28nm.c b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_28nm.c
index 26e3a01a99c2b..4a84c69ca0b2b 100644
--- a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_28nm.c
+++ b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_28nm.c
@@ -40,7 +40,7 @@

#define NUM_PROVIDED_CLKS 2

-#define VCO_REF_CLK_RATE 19200000
+#define VCO_REF_CLK_DEFAULT_RATE 19200000
#define VCO_MIN_RATE 350000000
#define VCO_MAX_RATE 750000000

@@ -81,6 +81,7 @@ struct dsi_pll_28nm {
struct platform_device *pdev;
void __iomem *mmio;

+ const char *vco_ref_clk_name;
int vco_delay;

/* private clocks: */
@@ -139,6 +140,8 @@ static int dsi_pll_28nm_clk_set_rate(struct clk_hw *hw, unsigned long rate,
struct dsi_pll_28nm *pll_28nm = to_pll_28nm(pll);
struct device *dev = &pll_28nm->pdev->dev;
void __iomem *base = pll_28nm->mmio;
+ unsigned long ref_clk_rate = parent_rate ?
+ parent_rate : VCO_REF_CLK_DEFAULT_RATE;
unsigned long div_fbx1000, gen_vco_clk;
u32 refclk_cfg, frac_n_mode, frac_n_value;
u32 sdm_cfg0, sdm_cfg1, sdm_cfg2, sdm_cfg3;
@@ -166,17 +169,17 @@ static int dsi_pll_28nm_clk_set_rate(struct clk_hw *hw, unsigned long rate,
pll_write(base + REG_DSI_28nm_PHY_PLL_LPFC1_CFG, 0x70);
pll_write(base + REG_DSI_28nm_PHY_PLL_LPFC2_CFG, 0x15);

- rem = rate % VCO_REF_CLK_RATE;
+ rem = rate % ref_clk_rate;
if (rem) {
refclk_cfg = DSI_28nm_PHY_PLL_REFCLK_CFG_DBLR;
frac_n_mode = 1;
- div_fbx1000 = rate / (VCO_REF_CLK_RATE / 500);
- gen_vco_clk = div_fbx1000 * (VCO_REF_CLK_RATE / 500);
+ div_fbx1000 = rate / (ref_clk_rate / 500);
+ gen_vco_clk = div_fbx1000 * (ref_clk_rate / 500);
} else {
refclk_cfg = 0x0;
frac_n_mode = 0;
- div_fbx1000 = rate / (VCO_REF_CLK_RATE / 1000);
- gen_vco_clk = div_fbx1000 * (VCO_REF_CLK_RATE / 1000);
+ div_fbx1000 = rate / (ref_clk_rate / 1000);
+ gen_vco_clk = div_fbx1000 * (ref_clk_rate / 1000);
}

DBG("refclk_cfg = %d", refclk_cfg);
@@ -265,7 +268,8 @@ static unsigned long dsi_pll_28nm_clk_recalc_rate(struct clk_hw *hw,
void __iomem *base = pll_28nm->mmio;
u32 sdm0, doubler, sdm_byp_div;
u32 sdm_dc_off, sdm_freq_seed, sdm2, sdm3;
- u32 ref_clk = VCO_REF_CLK_RATE;
+ u32 ref_clk = parent_rate ?
+ parent_rate : VCO_REF_CLK_DEFAULT_RATE;
unsigned long vco_rate;

VERB("parent_rate=%lu", parent_rate);
@@ -273,7 +277,7 @@ static unsigned long dsi_pll_28nm_clk_recalc_rate(struct clk_hw *hw,
/* Check to see if the ref clk doubler is enabled */
doubler = pll_read(base + REG_DSI_28nm_PHY_PLL_REFCLK_CFG) &
DSI_28nm_PHY_PLL_REFCLK_CFG_DBLR;
- ref_clk += (doubler * VCO_REF_CLK_RATE);
+ ref_clk += (doubler * ref_clk);

/* see if it is integer mode or sdm mode */
sdm0 = pll_read(base + REG_DSI_28nm_PHY_PLL_SDM_CFG0);
@@ -518,7 +522,7 @@ static int pll_28nm_register(struct dsi_pll_28nm *pll_28nm)
{
char clk_name[32], parent1[32], parent2[32], vco_name[32];
struct clk_init_data vco_init = {
- .parent_names = (const char *[]){ "xo" },
+ .parent_names = &pll_28nm->vco_ref_clk_name,
.num_parents = 1,
.name = vco_name,
.flags = CLK_IGNORE_UNUSED,
@@ -593,6 +597,7 @@ struct msm_dsi_pll *msm_dsi_pll_28nm_init(struct platform_device *pdev,
{
struct dsi_pll_28nm *pll_28nm;
struct msm_dsi_pll *pll;
+ struct clk *vco_ref_clk;
int ret;

if (!pdev)
@@ -605,6 +610,18 @@ struct msm_dsi_pll *msm_dsi_pll_28nm_init(struct platform_device *pdev,
pll_28nm->pdev = pdev;
pll_28nm->id = id;

+ vco_ref_clk = devm_clk_get(&pdev->dev, "ref");
+ if (!IS_ERR(vco_ref_clk)) {
+ pll_28nm->vco_ref_clk_name = __clk_get_name(vco_ref_clk);
+ } else {
+ ret = PTR_ERR(vco_ref_clk);
+ if (ret == -EPROBE_DEFER)
+ ERR_PTR(ret);
+
+ dev_warn(&pdev->dev, "'ref' clock is not specified, using default name\n");
+ pll_28nm->vco_ref_clk_name = "xo";
+ }
+
pll_28nm->mmio = msm_ioremap(pdev, "dsi_pll", "DSI_PLL");
if (IS_ERR_OR_NULL(pll_28nm->mmio)) {
dev_err(&pdev->dev, "%s: failed to map pll base\n", __func__);
--
2.20.0.rc1.387.gf8505762e3-goog