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Message-ID: <20160628153029.GC29166@dell>
Date: Tue, 28 Jun 2016 16:30:29 +0100
From: Lee Jones <lee.jones@...aro.org>
To: Peter Ujfalusi <peter.ujfalusi@...com>
Cc: linux-omap@...r.kernel.org, linux-kernel@...r.kernel.org,
tony@...mide.com, devicetree@...r.kernel.org, robh@...nel.org
Subject: Re: [PATCH v2] mfd: twl6040: Handle mclk used for HPPLL and optional
internal clock source
On Mon, 20 Jun 2016, Peter Ujfalusi wrote:
> On some boards, like omap5-uevm the MCLK is gated by default and in order
> to be able to use the High performance modes of twl6040 it need to be
> enabled by SW.
> Add support for handling the MCLK source clock via CCF.
> At the same time lower the print priority of the notification that the 32K
> clock is not provided and it is not going to be handled by the driver.
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@...com>
> Acked-by: Rob Herring <robh@...nel.org>
> ---
> Hi,
>
> Changes since v1:
> - Keep the clk32k name and use mclk for the new clock
> - rename the old mclk variable to mclk_rate and use it only to track the MCLK
> frequency
> - rename the sysclk to sysclk_rate also to be more explicit on the meaning of
> this variabe.
>
> Regards,
> Peter
>
> Documentation/devicetree/bindings/mfd/twl6040.txt | 4 +--
> drivers/mfd/twl6040.c | 41 ++++++++++++++++-------
> include/linux/mfd/twl6040.h | 5 +--
> 3 files changed, 34 insertions(+), 16 deletions(-)
Applied, thanks.
> diff --git a/Documentation/devicetree/bindings/mfd/twl6040.txt b/Documentation/devicetree/bindings/mfd/twl6040.txt
> index a41157b5d930..e6afdfa3543d 100644
> --- a/Documentation/devicetree/bindings/mfd/twl6040.txt
> +++ b/Documentation/devicetree/bindings/mfd/twl6040.txt
> @@ -19,8 +19,8 @@ Required properties:
>
> Optional properties, nodes:
> - enable-active-high: To power on the twl6040 during boot.
> -- clocks: phandle to the clk32k clock provider
> -- clock-names: Must be "clk32k"
> +- clocks: phandle to the clk32k and/or to mclk clock provider
> +- clock-names: Must be "clk32k" for the 32K clock and "mclk" for the MCLK.
>
> Vibra functionality
> Required properties:
> diff --git a/drivers/mfd/twl6040.c b/drivers/mfd/twl6040.c
> index 852d5874aabb..ab328ec49353 100644
> --- a/drivers/mfd/twl6040.c
> +++ b/drivers/mfd/twl6040.c
> @@ -323,8 +323,7 @@ int twl6040_power(struct twl6040 *twl6040, int on)
>
> /* Default PLL configuration after power up */
> twl6040->pll = TWL6040_SYSCLK_SEL_LPPLL;
> - twl6040->sysclk = 19200000;
> - twl6040->mclk = 32768;
> + twl6040->sysclk_rate = 19200000;
> } else {
> /* already powered-down */
> if (!twl6040->power_count) {
> @@ -352,8 +351,12 @@ int twl6040_power(struct twl6040 *twl6040, int on)
> regcache_cache_only(twl6040->regmap, true);
> regcache_mark_dirty(twl6040->regmap);
>
> - twl6040->sysclk = 0;
> - twl6040->mclk = 0;
> + twl6040->sysclk_rate = 0;
> +
> + if (twl6040->pll == TWL6040_SYSCLK_SEL_HPPLL) {
> + clk_disable_unprepare(twl6040->mclk);
> + twl6040->mclk_rate = 0;
> + }
>
> clk_disable_unprepare(twl6040->clk32k);
> }
> @@ -377,15 +380,15 @@ int twl6040_set_pll(struct twl6040 *twl6040, int pll_id,
>
> /* Force full reconfiguration when switching between PLL */
> if (pll_id != twl6040->pll) {
> - twl6040->sysclk = 0;
> - twl6040->mclk = 0;
> + twl6040->sysclk_rate = 0;
> + twl6040->mclk_rate = 0;
> }
>
> switch (pll_id) {
> case TWL6040_SYSCLK_SEL_LPPLL:
> /* low-power PLL divider */
> /* Change the sysclk configuration only if it has been canged */
> - if (twl6040->sysclk != freq_out) {
> + if (twl6040->sysclk_rate != freq_out) {
> switch (freq_out) {
> case 17640000:
> lppllctl |= TWL6040_LPLLFIN;
> @@ -427,6 +430,8 @@ int twl6040_set_pll(struct twl6040 *twl6040, int pll_id,
> ret = -EINVAL;
> goto pll_out;
> }
> +
> + clk_disable_unprepare(twl6040->mclk);
> break;
> case TWL6040_SYSCLK_SEL_HPPLL:
> /* high-performance PLL can provide only 19.2 MHz */
> @@ -437,7 +442,7 @@ int twl6040_set_pll(struct twl6040 *twl6040, int pll_id,
> goto pll_out;
> }
>
> - if (twl6040->mclk != freq_in) {
> + if (twl6040->mclk_rate != freq_in) {
> hppllctl &= ~TWL6040_MCLK_MSK;
>
> switch (freq_in) {
> @@ -468,6 +473,9 @@ int twl6040_set_pll(struct twl6040 *twl6040, int pll_id,
> goto pll_out;
> }
>
> + /* When switching to HPPLL, enable the mclk first */
> + if (pll_id != twl6040->pll)
> + clk_prepare_enable(twl6040->mclk);
> /*
> * enable clock slicer to ensure input waveform is
> * square
> @@ -483,6 +491,8 @@ int twl6040_set_pll(struct twl6040 *twl6040, int pll_id,
> lppllctl &= ~TWL6040_LPLLENA;
> twl6040_reg_write(twl6040, TWL6040_REG_LPPLLCTL,
> lppllctl);
> +
> + twl6040->mclk_rate = freq_in;
> }
> break;
> default:
> @@ -491,8 +501,7 @@ int twl6040_set_pll(struct twl6040 *twl6040, int pll_id,
> goto pll_out;
> }
>
> - twl6040->sysclk = freq_out;
> - twl6040->mclk = freq_in;
> + twl6040->sysclk_rate = freq_out;
> twl6040->pll = pll_id;
>
> pll_out:
> @@ -512,7 +521,7 @@ EXPORT_SYMBOL(twl6040_get_pll);
>
> unsigned int twl6040_get_sysclk(struct twl6040 *twl6040)
> {
> - return twl6040->sysclk;
> + return twl6040->sysclk_rate;
> }
> EXPORT_SYMBOL(twl6040_get_sysclk);
>
> @@ -655,10 +664,18 @@ static int twl6040_probe(struct i2c_client *client,
> if (IS_ERR(twl6040->clk32k)) {
> if (PTR_ERR(twl6040->clk32k) == -EPROBE_DEFER)
> return -EPROBE_DEFER;
> - dev_info(&client->dev, "clk32k is not handled\n");
> + dev_dbg(&client->dev, "clk32k is not handled\n");
> twl6040->clk32k = NULL;
> }
>
> + twl6040->mclk = devm_clk_get(&client->dev, "mclk");
> + if (IS_ERR(twl6040->mclk)) {
> + if (PTR_ERR(twl6040->mclk) == -EPROBE_DEFER)
> + return -EPROBE_DEFER;
> + dev_dbg(&client->dev, "mclk is not handled\n");
> + twl6040->mclk = NULL;
> + }
> +
> twl6040->supplies[0].supply = "vio";
> twl6040->supplies[1].supply = "v2v1";
> ret = devm_regulator_bulk_get(&client->dev, TWL6040_NUM_SUPPLIES,
> diff --git a/include/linux/mfd/twl6040.h b/include/linux/mfd/twl6040.h
> index 8e95cd87cd74..36795a1be479 100644
> --- a/include/linux/mfd/twl6040.h
> +++ b/include/linux/mfd/twl6040.h
> @@ -226,6 +226,7 @@ struct twl6040 {
> struct regmap_irq_chip_data *irq_data;
> struct regulator_bulk_data supplies[2]; /* supplies for vio, v2v1 */
> struct clk *clk32k;
> + struct clk *mclk;
> struct mutex mutex;
> struct mutex irq_mutex;
> struct mfd_cell cells[TWL6040_CELLS];
> @@ -237,8 +238,8 @@ struct twl6040 {
>
> /* PLL configuration */
> int pll;
> - unsigned int sysclk;
> - unsigned int mclk;
> + unsigned int sysclk_rate;
> + unsigned int mclk_rate;
>
> unsigned int irq;
> unsigned int irq_ready;
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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