Messages in this thread | | | Date | Tue, 29 Jul 2014 17:35:39 +0800 | From | caesar <> | Subject | Re: [PATCH v2 2/2] pwm: add this patch to support the new pwm of Rockchip SoCs |
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Hi Olof,
Sorry, I didn't understand all of what you mean. Please allow me to paste the following code [1].
在 2014年07月29日 00:58, Olof Johansson 写道: > On Mon, Jul 28, 2014 at 4:19 AM, caesar <caesar.wang@rock-chips.com> wrote: >> Doug, >> 在 2014年07月28日 12:01, Doug Anderson 写道: >> >>> Caesar, >>> >>> On Sun, Jul 27, 2014 at 7:00 AM, caesar <caesar.wang@rock-chips.com> >>> wrote: >>>> /*I think will be show the faill log:-> >>>> >>>> * rockchip-pwm ff9301a0.pwm: can't request region for resource [mem >>>> 0xff9301a0-0xff93019f] >>>> */ >>>> >>>> pc->base = devm_ioremap_resource(dev, regs); >>> Did you actually code this up and try it and get this error? >> Yeah. >> >>> I hadn't >>> tried it but I researched other dts files and it looked as if there >>> was one example that was doing this. ...but perhaps it wasn't >>> actually doing the ioremap_resource on both ranges. >>> >>> I'd imagine that this is _probably_ equivalent to what Thierry was >>> suggesting, so if it didn't work then maybe Thierry's won't work >>> either? >>> >>> I don't have any other great suggestions other than doing two memory >>> ranges for lcdc: >>> >>> lcdc@ff930000 { >>> compatible = "rockchip,rk3288-lcdc"; >>> reg = <0xff930000 0x1a0>, <0xff9301b0 0xfe50>; >>> ... >>> }; >>> pwm@ff9301a0 { >>> compatible = "rockchip,vop-pwm"; >>> reg = <0xff9301a0 0x10>; >>> ... >>> }; >>> >>> ...but I am certainly nowhere near an expert on this stuff... >>> >>> -Doug >>> >>> >>> >> I has solve in lcdc driver,but I always feel awkward. I think a good way to >> solve in pwm driver. >> Unfortunately that so far ,I have not a good idle in pwm driver. >> >> Maybe,I let do it that way in lcdc driver. > I think there's an easier way to do this, by not focusing _too_ much > on the device tree: > > * Define a platform_data structure for the PWM driver, which contains > readl/writel accessors as well as the device type (i.e. what you use > the compatible field and the lookup table for today). Maybe, as the following code: "pwm_data_vop" has been implement it. right? > * Populate the platform_device in the clcd driver, and register that Yeah,the lcdc driver can register it. > * Make the PWM driver probe as a regular platform device if pdata is passed > * Make a readl/writel wrapper that either falls back to native > readl/writel when there aren't any passed in, or make the DT code fill > in the pdata with the native versions in that case. Sorry,This step I don't understand it. Perhaps, could you give a simple case for it ?:-P
> Going full MFD on this seems overkill, unless there is also a shared > interrupt that needs to be handled. > > -Olof > > > >
[1]:The driver/pwm/pwm-rockchip.c
#include <linux/clk.h> #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/time.h>
#define PWM_CNTR 0x00 /* Counter register */ #define PWM_HRC 0x04 /* High reference register */ #define PWM_LRC 0x08 /* Low reference register */ #define PWM_CTRL 0x0c /* Control register */ #define PWM_CTRL_TIMER_EN (1 << 0) #define PWM_CTRL_OUTPUT_EN (1 << 3)
#define PRESCALER 2
#define PWM_ENABLE (1 << 0) #define PWM_CONTINUOUS (1 << 1) #define PWM_DUTY_POSITIVE (1 << 3) #define PWM_INACTIVE_NEGATIVE (0 << 4) #define PWM_OUTPUT_LEFT (0 << 5) #define PWM_LP_DISABLE (0 << 8)
struct rockchip_pwm_chip { struct pwm_chip chip; struct clk *clk; const struct rockchip_pwm_data *data; void __iomem *base; };
struct rockchip_pwm_regs { unsigned long duty; unsigned long period; unsigned long cntr; unsigned long ctrl; };
struct rockchip_pwm_data { struct rockchip_pwm_regs regs; unsigned int prescaler;
void (*set_enable)(struct pwm_chip *chip, bool enable); };
static inline struct rockchip_pwm_chip *to_rockchip_pwm_chip(struct pwm_chip *c) { return container_of(c, struct rockchip_pwm_chip, chip); }
static void rockchip_pwm_set_enable_v1(struct pwm_chip *chip, bool enable) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); u32 val = 0; u32 enable_conf = PWM_CTRL_OUTPUT_EN | PWM_CTRL_TIMER_EN;
val = readl_relaxed(pc->base + pc->data->regs.ctrl);
if (enable) val |= enable_conf; else val &= ~enable_conf;
writel_relaxed(val, pc->base + pc->data->regs.ctrl); }
static void rockchip_pwm_set_enable_v2(struct pwm_chip *chip, bool enable) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); u32 val = 0; u32 enable_conf = PWM_OUTPUT_LEFT | PWM_LP_DISABLE | PWM_ENABLE | PWM_CONTINUOUS | PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
val = readl_relaxed(pc->base + pc->data->regs.ctrl);
if (enable) val |= enable_conf; else val &= ~enable_conf;
writel_relaxed(val, pc->base + pc->data->regs.ctrl); }
static int rockchip_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); unsigned long period, duty; u64 clk_rate, div; int ret;
clk_rate = clk_get_rate(pc->clk);
/* * Since period and duty cycle registers have a width of 32 * bits, every possible input period can be obtained using the * default prescaler value for all practical clock rate values. */ div = clk_rate * period_ns; do_div(div, pc->data->prescaler * NSEC_PER_SEC); period = div;
div = clk_rate * duty_ns; do_div(div, pc->data->prescaler * NSEC_PER_SEC); duty = div;
ret = clk_enable(pc->clk); if (ret) return ret;
writel(period, pc->base + pc->data->regs.period); writel(duty, pc->base + pc->data->regs.duty); writel(0, pc->base + pc->data->regs.cntr);
clk_disable(pc->clk);
return 0; }
static int rockchip_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip); int ret;
ret = clk_enable(pc->clk); if (ret) return ret;
pc->data->set_enable(chip, true);
return 0; }
static void rockchip_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) { struct rockchip_pwm_chip *pc = to_rockchip_pwm_chip(chip);
pc->data->set_enable(chip, false);
clk_disable(pc->clk); }
static const struct pwm_ops rockchip_pwm_ops = { .config = rockchip_pwm_config, .enable = rockchip_pwm_enable, .disable = rockchip_pwm_disable, .owner = THIS_MODULE, };
static const struct rockchip_pwm_data pwm_data_v1 = { .regs.duty = PWM_HRC, .regs.period = PWM_LRC, .regs.cntr = PWM_CNTR, .regs.ctrl = PWM_CTRL, .prescaler = PRESCALER, .set_enable = rockchip_pwm_set_enable_v1, };
static const struct rockchip_pwm_data pwm_data_v2 = { .regs.duty = PWM_LRC, .regs.period = PWM_HRC, .regs.cntr = PWM_CNTR, .regs.ctrl = PWM_CTRL, .prescaler = PRESCALER-1, .set_enable = rockchip_pwm_set_enable_v2, };
static const struct rockchip_pwm_data pwm_data_vop = { .regs.duty = PWM_LRC, .regs.period = PWM_HRC, .regs.cntr = PWM_CTRL, .regs.ctrl = PWM_CNTR, .prescaler = PRESCALER-1, .set_enable = rockchip_pwm_set_enable_v2, };
static const struct of_device_id rockchip_pwm_dt_ids[] = { { .compatible = "rockchip,rk2928-pwm", .data = &pwm_data_v1}, { .compatible = "rockchip,rk3288-pwm", .data = &pwm_data_v2}, { .compatible = "rockchip,vop-pwm", .data = &pwm_data_vop}, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, rockchip_pwm_dt_ids);
static int rockchip_pwm_probe(struct platform_device *pdev) { const struct of_device_id *id; struct rockchip_pwm_chip *pc; struct resource *r; int ret;
id = of_match_device(rockchip_pwm_dt_ids, &pdev->dev); if (!id) return -EINVAL;
pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL); if (!pc) return -ENOMEM;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0); pc->base = devm_ioremap_resource(&pdev->dev, r); if (IS_ERR(pc->base)) return PTR_ERR(pc->base);
pc->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(pc->clk)) return PTR_ERR(pc->clk);
ret = clk_prepare(pc->clk); if (ret) return ret;
platform_set_drvdata(pdev, pc);
pc->data = id->data; pc->chip.dev = &pdev->dev; pc->chip.ops = &rockchip_pwm_ops; pc->chip.base = -1; pc->chip.npwm = 1;
ret = pwmchip_add(&pc->chip); if (ret < 0) { clk_unprepare(pc->clk); dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret); }
return ret; }
static int rockchip_pwm_remove(struct platform_device *pdev) { struct rockchip_pwm_chip *pc = platform_get_drvdata(pdev);
clk_unprepare(pc->clk);
return pwmchip_remove(&pc->chip); }
static struct platform_driver rockchip_pwm_driver = { .driver = { .name = "rockchip-pwm", .of_match_table = rockchip_pwm_dt_ids, }, .probe = rockchip_pwm_probe, .remove = rockchip_pwm_remove, }; module_platform_driver(rockchip_pwm_driver);
MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>"); MODULE_DESCRIPTION("Rockchip SoC PWM driver"); MODULE_LICENSE("GPL v2");
-Caesar
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