[PATCH 2/3] pwm: Add MediaTek MT2701 display PWM driver support
weiqing kong
weiqing.kong at mediatek.com
Wed Jun 8 00:21:18 PDT 2016
On Fri, 2016-06-03 at 17:35 +0200, Matthias Brugger wrote:
>
> On 30/05/16 10:41, Weiqing Kong wrote:
> > Use the mtk_pwm_data struction to define different registers
> > and add MT2701 specific register operations, such as MT2701
> > doesn't have commit register, needs to disable double buffer
> > before writing register, and needs to select manual mode
> > and use PWM_PERIOD/PWM_HIGH_WIDTH.
> >
> > Signed-off-by: Weiqing Kong <weiqing.kong at mediatek.com>
> > ---
> > drivers/pwm/pwm-mtk-disp.c | 89 +++++++++++++++++++++++++++++++++++++---------
> > 1 file changed, 72 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/pwm/pwm-mtk-disp.c b/drivers/pwm/pwm-mtk-disp.c
> > index 0ad3385..03b9c9e 100644
> > --- a/drivers/pwm/pwm-mtk-disp.c
> > +++ b/drivers/pwm/pwm-mtk-disp.c
> > @@ -18,33 +18,44 @@
> > #include <linux/io.h>
> > #include <linux/module.h>
> > #include <linux/of.h>
> > +#include <linux/of_device.h>
> > #include <linux/platform_device.h>
> > #include <linux/pwm.h>
> > #include <linux/slab.h>
> >
> > #define DISP_PWM_EN 0x00
> > -#define PWM_ENABLE_MASK BIT(0)
> >
> > #define DISP_PWM_COMMIT 0x08
> > #define PWM_COMMIT_MASK BIT(0)
> >
> > -#define DISP_PWM_CON_0 0x10
> > #define PWM_CLKDIV_SHIFT 16
> > #define PWM_CLKDIV_MAX 0x3ff
> > #define PWM_CLKDIV_MASK (PWM_CLKDIV_MAX << PWM_CLKDIV_SHIFT)
> >
> > -#define DISP_PWM_CON_1 0x14
> > #define PWM_PERIOD_BIT_WIDTH 12
> > #define PWM_PERIOD_MASK ((1 << PWM_PERIOD_BIT_WIDTH) - 1)
> >
> > #define PWM_HIGH_WIDTH_SHIFT 16
> > #define PWM_HIGH_WIDTH_MASK (0x1fff << PWM_HIGH_WIDTH_SHIFT)
> >
> > +#define MT2701_PWM_MANUAL_SEL_MASK BIT(1)
> > +#define MT2701_PWM_BLS_DEBUG 0xb0
>
> Do we need to set magic 0x3 in the debug register? If so, this should be
> part of mtk_pwm_data, just as con0_sel.
Do you mean that add bls_debug into struct mtk_pwm_data,
and set 0x3 in mt2701 data, 0x0 in mt8173 data?
>
> > +#define MT2701_PWM_BLS_DEBUG_MASK 0x3
> > +
> > +struct mtk_pwm_data {
> > + unsigned int enable_bit;
> > + unsigned int con0;
> > + unsigned int con0_sel;
> > + unsigned int con1;
> > + bool have_commit_reg;
> > +};
> > +
> > struct mtk_disp_pwm {
> > struct pwm_chip chip;
> > struct clk *clk_main;
> > struct clk *clk_mm;
> > void __iomem *base;
> > + const struct mtk_pwm_data *data;
>
> Couldn't that just be the offset for the commit register and set it to
> 0x0 if the commit register is not present. Right now, we suppose the
> DISP_PWM_EN is at offset 0x0, so this should not be a problem.
>
Do you mean that replace have_commit_reg with commit_reg_offset?
just like this?
bool have_commit_reg;
->
unsigned int commit_reg_offset;
and set commit_reg_offset 0x0 in mt2701, 0x1 in mt8173?
> > };
> >
> > static inline struct mtk_disp_pwm *to_mtk_disp_pwm(struct pwm_chip *chip)
> > @@ -106,12 +117,18 @@ static int mtk_disp_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
> > return err;
> > }
> >
> > - mtk_disp_pwm_update_bits(mdp, DISP_PWM_CON_0, PWM_CLKDIV_MASK,
> > + mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
> > + PWM_CLKDIV_MASK,
> > clk_div << PWM_CLKDIV_SHIFT);
> > - mtk_disp_pwm_update_bits(mdp, DISP_PWM_CON_1,
> > - PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK, value);
> > - mtk_disp_pwm_update_bits(mdp, DISP_PWM_COMMIT, PWM_COMMIT_MASK, 1);
> > - mtk_disp_pwm_update_bits(mdp, DISP_PWM_COMMIT, PWM_COMMIT_MASK, 0);
> > + mtk_disp_pwm_update_bits(mdp, mdp->data->con1,
> > + PWM_PERIOD_MASK | PWM_HIGH_WIDTH_MASK,
> > + value);
> > + if (mdp->data->have_commit_reg) {
> > + mtk_disp_pwm_update_bits(mdp, DISP_PWM_COMMIT,
> > + PWM_COMMIT_MASK, 0x1);
> > + mtk_disp_pwm_update_bits(mdp, DISP_PWM_COMMIT,
> > + PWM_COMMIT_MASK, 0x0);
>
> should be renamed to MT8173_PWM_COMMIT_MASK, although I'm not really a
> friend of mixing up SoC specific defines with a Soc specific
> mtk_disp_pwm structure.
>
> Regards,
> Matthias
ok, I will modify it as you said. thanks for you suggestion.
>
> > + }
> >
> > clk_disable(mdp->clk_mm);
> > clk_disable(mdp->clk_main);
> > @@ -134,7 +151,9 @@ static int mtk_disp_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
> > return err;
> > }
> >
> > - mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, PWM_ENABLE_MASK, 1);
> > + mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN,
> > + mdp->data->enable_bit,
> > + mdp->data->enable_bit);
> >
> > return 0;
> > }
> > @@ -143,7 +162,8 @@ static void mtk_disp_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
> > {
> > struct mtk_disp_pwm *mdp = to_mtk_disp_pwm(chip);
> >
> > - mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN, PWM_ENABLE_MASK, 0);
> > + mtk_disp_pwm_update_bits(mdp, DISP_PWM_EN,
> > + mdp->data->enable_bit, 0x0);
> >
> > clk_disable(mdp->clk_mm);
> > clk_disable(mdp->clk_main);
> > @@ -156,12 +176,41 @@ static const struct pwm_ops mtk_disp_pwm_ops = {
> > .owner = THIS_MODULE,
> > };
> >
> > +static const struct mtk_pwm_data mt8173_pwm_data = {
> > + .enable_bit = BIT(0),
> > + .con0 = 0x10,
> > + .con0_sel = 0x0,
> > + .con1 = 0x14,
> > + .have_commit_reg = true,
> > +};
> > +
> > +static const struct mtk_pwm_data mt2701_pwm_data = {
> > + .enable_bit = BIT(16),
> > + .con0 = 0xa8,
> > + .con0_sel = 0x2,
> > + .con1 = 0xac,
> > + .have_commit_reg = false,
> > +};
> > +
> > +static const struct of_device_id mtk_disp_pwm_of_match[] = {
> > + { .compatible = "mediatek,mt2701-disp-bls", .data = &mt2701_pwm_data},
> > + { .compatible = "mediatek,mt6595-disp-pwm", .data = &mt8173_pwm_data},
> > + { .compatible = "mediatek,mt8173-disp-pwm", .data = &mt8173_pwm_data},
> > + { }
> > +};
> > +MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match);
> > +
> > static int mtk_disp_pwm_probe(struct platform_device *pdev)
> > {
> > + const struct of_device_id *id;
> > struct mtk_disp_pwm *mdp;
> > struct resource *r;
> > int ret;
> >
> > + id = of_match_device(mtk_disp_pwm_of_match, &pdev->dev);
> > + if (!id)
> > + return -EINVAL;
> > +
> > mdp = devm_kzalloc(&pdev->dev, sizeof(*mdp), GFP_KERNEL);
> > if (!mdp)
> > return -ENOMEM;
> > @@ -191,6 +240,7 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
> > mdp->chip.ops = &mtk_disp_pwm_ops;
> > mdp->chip.base = -1;
> > mdp->chip.npwm = 1;
> > + mdp->data = id->data;
> >
> > ret = pwmchip_add(&mdp->chip);
> > if (ret < 0) {
> > @@ -200,6 +250,18 @@ static int mtk_disp_pwm_probe(struct platform_device *pdev)
> >
> > platform_set_drvdata(pdev, mdp);
> >
> > + /*
> > + * For MT2701, disable double buffer before writing register
> > + * and select manual mode and use PWM_PERIOD/PWM_HIGH_WIDTH.
> > + */
> > + if (!mdp->data->have_commit_reg) {
> > + mtk_disp_pwm_update_bits(mdp, MT2701_PWM_BLS_DEBUG,
> > + MT2701_PWM_BLS_DEBUG_MASK, 0x3);
> > + mtk_disp_pwm_update_bits(mdp, mdp->data->con0,
> > + MT2701_PWM_MANUAL_SEL_MASK,
> > + mdp->data->con0_sel);
> > + }
> > +
> > return 0;
> >
> > disable_clk_mm:
> > @@ -221,13 +283,6 @@ static int mtk_disp_pwm_remove(struct platform_device *pdev)
> > return ret;
> > }
> >
> > -static const struct of_device_id mtk_disp_pwm_of_match[] = {
> > - { .compatible = "mediatek,mt8173-disp-pwm" },
> > - { .compatible = "mediatek,mt6595-disp-pwm" },
> > - { }
> > -};
> > -MODULE_DEVICE_TABLE(of, mtk_disp_pwm_of_match);
> > -
> > static struct platform_driver mtk_disp_pwm_driver = {
> > .driver = {
> > .name = "mediatek-disp-pwm",
> >
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