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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/gpu/drm/sun4i/sun4i_hdmi_ddc_clk.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/gpu/drm/sun4i/sun4i_hdmi_ddc_clk.c')
-rw-r--r-- | drivers/gpu/drm/sun4i/sun4i_hdmi_ddc_clk.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/gpu/drm/sun4i/sun4i_hdmi_ddc_clk.c b/drivers/gpu/drm/sun4i/sun4i_hdmi_ddc_clk.c new file mode 100644 index 000000000..12430b9d4 --- /dev/null +++ b/drivers/gpu/drm/sun4i/sun4i_hdmi_ddc_clk.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2016 Free Electrons + * Copyright (C) 2016 NextThing Co + * + * Maxime Ripard <maxime.ripard@free-electrons.com> + */ + +#include <linux/clk-provider.h> +#include <linux/regmap.h> + +#include "sun4i_hdmi.h" + +struct sun4i_ddc { + struct clk_hw hw; + struct sun4i_hdmi *hdmi; + struct regmap_field *reg; + u8 pre_div; + u8 m_offset; +}; + +static inline struct sun4i_ddc *hw_to_ddc(struct clk_hw *hw) +{ + return container_of(hw, struct sun4i_ddc, hw); +} + +static unsigned long sun4i_ddc_calc_divider(unsigned long rate, + unsigned long parent_rate, + const u8 pre_div, + const u8 m_offset, + u8 *m, u8 *n) +{ + unsigned long best_rate = 0; + u8 best_m = 0, best_n = 0, _m, _n; + + for (_m = 0; _m < 16; _m++) { + for (_n = 0; _n < 8; _n++) { + unsigned long tmp_rate; + + tmp_rate = (((parent_rate / pre_div) / 10) >> _n) / + (_m + m_offset); + + if (tmp_rate > rate) + continue; + + if (abs(rate - tmp_rate) < abs(rate - best_rate)) { + best_rate = tmp_rate; + best_m = _m; + best_n = _n; + } + } + } + + if (m && n) { + *m = best_m; + *n = best_n; + } + + return best_rate; +} + +static long sun4i_ddc_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + struct sun4i_ddc *ddc = hw_to_ddc(hw); + + return sun4i_ddc_calc_divider(rate, *prate, ddc->pre_div, + ddc->m_offset, NULL, NULL); +} + +static unsigned long sun4i_ddc_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct sun4i_ddc *ddc = hw_to_ddc(hw); + unsigned int reg; + u8 m, n; + + regmap_field_read(ddc->reg, ®); + m = (reg >> 3) & 0xf; + n = reg & 0x7; + + return (((parent_rate / ddc->pre_div) / 10) >> n) / + (m + ddc->m_offset); +} + +static int sun4i_ddc_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct sun4i_ddc *ddc = hw_to_ddc(hw); + u8 div_m, div_n; + + sun4i_ddc_calc_divider(rate, parent_rate, ddc->pre_div, + ddc->m_offset, &div_m, &div_n); + + regmap_field_write(ddc->reg, + SUN4I_HDMI_DDC_CLK_M(div_m) | + SUN4I_HDMI_DDC_CLK_N(div_n)); + + return 0; +} + +static const struct clk_ops sun4i_ddc_ops = { + .recalc_rate = sun4i_ddc_recalc_rate, + .round_rate = sun4i_ddc_round_rate, + .set_rate = sun4i_ddc_set_rate, +}; + +int sun4i_ddc_create(struct sun4i_hdmi *hdmi, struct clk *parent) +{ + struct clk_init_data init; + struct sun4i_ddc *ddc; + const char *parent_name; + + parent_name = __clk_get_name(parent); + if (!parent_name) + return -ENODEV; + + ddc = devm_kzalloc(hdmi->dev, sizeof(*ddc), GFP_KERNEL); + if (!ddc) + return -ENOMEM; + + ddc->reg = devm_regmap_field_alloc(hdmi->dev, hdmi->regmap, + hdmi->variant->ddc_clk_reg); + if (IS_ERR(ddc->reg)) + return PTR_ERR(ddc->reg); + + init.name = "hdmi-ddc"; + init.ops = &sun4i_ddc_ops; + init.parent_names = &parent_name; + init.num_parents = 1; + + ddc->hdmi = hdmi; + ddc->hw.init = &init; + ddc->pre_div = hdmi->variant->ddc_clk_pre_divider; + ddc->m_offset = hdmi->variant->ddc_clk_m_offset; + + hdmi->ddc_clk = devm_clk_register(hdmi->dev, &ddc->hw); + if (IS_ERR(hdmi->ddc_clk)) + return PTR_ERR(hdmi->ddc_clk); + + return 0; +} |