[PATCH v2 4/4] clk: meson: gxbb-aoclk: Add CEC 32k clock
From: martin.blumenstingl@googlemail.com (Martin Blumenstingl)
Date: 2017-07-28 10:30:11
Also in:
linux-amlogic, linux-clk, lkml
Hi Neil, thanks for these patches, CEC support is another good step! On Fri, Jul 28, 2017 at 11:53 AM, Neil Armstrong [off-list ref] wrote:
quoted hunk ↗ jump to hunk
The CEC 32K AO Clock is a dual divider with dual counter to provide a more precise 32768Hz clock for the CEC subsystem from the external xtal. Signed-off-by: Neil Armstrong <redacted> --- drivers/clk/meson/Makefile | 2 +- drivers/clk/meson/gxbb-aoclk-32k.c | 180 +++++++++++++++++++++++++++++++++++++ drivers/clk/meson/gxbb-aoclk.c | 21 ++++- drivers/clk/meson/gxbb-aoclk.h | 16 ++++ 4 files changed, 217 insertions(+), 2 deletions(-) create mode 100644 drivers/clk/meson/gxbb-aoclk-32k.cdiff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile index de65427..b139d41 100644 --- a/drivers/clk/meson/Makefile +++ b/drivers/clk/meson/Makefile@@ -4,4 +4,4 @@ obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-cpu.o clk-mpll.o clk-audio-divider.o obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o -obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o gxbb-aoclk-regmap.o +obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o gxbb-aoclk-regmap.o gxbb-aoclk-32k.odiff --git a/drivers/clk/meson/gxbb-aoclk-32k.c b/drivers/clk/meson/gxbb-aoclk-32k.c new file mode 100644 index 0000000..497cd09 --- /dev/null +++ b/drivers/clk/meson/gxbb-aoclk-32k.c@@ -0,0 +1,180 @@ +/* + * Copyright (c) 2017 BayLibre, SAS. + * Author: Neil Armstrong <narmstrong@baylibre.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <linux/clk-provider.h> +#include <linux/bitfield.h> +#include <linux/regmap.h> +#include "gxbb-aoclk.h" + +/* + * The AO Domain embeds a dual/divider to generate a more precise + * 32,768KHz clock for low-power suspend mode and CEC. + */ + +#define CLK_CNTL0_N1_MASK GENMASK(11, 0) +#define CLK_CNTL0_N2_MASK GENMASK(23, 12) +#define CLK_CNTL0_DUALDIV_EN BIT(28) +#define CLK_CNTL0_OUT_GATE_EN BIT(30) +#define CLK_CNTL0_IN_GATE_EN BIT(31) + +#define CLK_CNTL1_M1_MASK GENMASK(11, 0) +#define CLK_CNTL1_M2_MASK GENMASK(23, 12) +#define CLK_CNTL1_BYPASS_EN BIT(24) +#define CLK_CNTL1_SELECT_OSC BIT(27) + +#define PWR_CNTL_ALT_32K_SEL GENMASK(13, 10) + +struct cec_32k_freq_table { + unsigned long parent_rate; + unsigned long target_rate; + bool dualdiv; + unsigned int n1; + unsigned int n2; + unsigned int m1; + unsigned int m2; +}; + +static const struct cec_32k_freq_table aoclk_cec_32k_table[] = { + [0] = { + .parent_rate = 24000000,
shouldn't you add a parent (XTAL) to this new clock so you could get rid of this?
+ .target_rate = 32768,
+ .dualdiv = true,
+ .n1 = 733,
+ .n2 = 732,
+ .m1 = 8,
+ .m2 = 11,
+ },
+};
+
+/*
+ * If CLK_CNTL0_DUALDIV_EN == 0
+ * - will use N1 divider only
+ * If CLK_CNTL0_DUALDIV_EN == 1
+ * - hold M1 cycles of N1 divider then changes to N2
+ * - hold M2 cycles of N2 divider then changes to N1
+ * Then we can get more accurate division.
+ */
+static unsigned long aoclk_cec_32k_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct aoclk_cec_32k *cec_32k = to_aoclk_cec_32k(hw);
+ unsigned long n1;
+ u32 reg0, reg1;
+
+ regmap_read(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0, ®0);
+ regmap_read(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL1, ®1);
+
+ if (reg1 & CLK_CNTL1_BYPASS_EN)
+ return parent_rate;
+
+ if (reg0 & CLK_CNTL0_DUALDIV_EN) {
+ unsigned long n2, m1, m2, f1, f2, p1, p2;
+
+ n1 = FIELD_GET(CLK_CNTL0_N1_MASK, reg0) + 1;
+ n2 = FIELD_GET(CLK_CNTL0_N2_MASK, reg0) + 1;
+
+ m1 = FIELD_GET(CLK_CNTL1_M1_MASK, reg1) + 1;
+ m2 = FIELD_GET(CLK_CNTL1_M2_MASK, reg1) + 1;
+
+ f1 = DIV_ROUND_CLOSEST(parent_rate, n1);
+ f2 = DIV_ROUND_CLOSEST(parent_rate, n2);
+
+ p1 = DIV_ROUND_CLOSEST(100000000 * m1, f1 * (m1 + m2));
+ p2 = DIV_ROUND_CLOSEST(100000000 * m2, f2 * (m1 + m2));
+
+ return DIV_ROUND_UP(100000000, p1 + p2);
+ }
+
+ n1 = FIELD_GET(CLK_CNTL0_N1_MASK, reg0) + 1;
+
+ return DIV_ROUND_CLOSEST(parent_rate, n1);
+}
+
+static const struct cec_32k_freq_table *find_cec_32k_freq(unsigned long rate,
+ unsigned long prate)
+{
+ int i;
+
+ for (i = 0 ; i < ARRAY_SIZE(aoclk_cec_32k_table) ; ++i)
+ if (aoclk_cec_32k_table[i].parent_rate == prate &&
+ aoclk_cec_32k_table[i].target_rate == rate)
+ return &aoclk_cec_32k_table[i];
+
+ return NULL;
+}
+
+static long aoclk_cec_32k_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ const struct cec_32k_freq_table *freq = find_cec_32k_freq(rate,
+ *prate);
+
+ /* If invalid return first one */
+ if (!freq)
+ return freq[0].target_rate;
+
+ return freq->target_rate;
+}
+
+static int aoclk_cec_32k_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ const struct cec_32k_freq_table *freq = find_cec_32k_freq(rate,
+ parent_rate);
+ struct aoclk_cec_32k *cec_32k = to_aoclk_cec_32k(hw);
+ u32 reg = 0;
+
+ if (!freq)
+ return -EINVAL;
+
+ /* Disable clock */
+ regmap_update_bits(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0,
+ CLK_CNTL0_IN_GATE_EN | CLK_CNTL0_OUT_GATE_EN, 0);
+
+ if (freq->dualdiv)
+ reg = CLK_CNTL0_DUALDIV_EN |
+ FIELD_PREP(CLK_CNTL0_N1_MASK, freq->n1 - 1) |
+ FIELD_PREP(CLK_CNTL0_N2_MASK, freq->n2 - 1);
+ else
+ reg = FIELD_PREP(CLK_CNTL0_N1_MASK, freq->n1 - 1);
+
+ regmap_write(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0, reg);
+
+ if (freq->dualdiv)
+ reg = FIELD_PREP(CLK_CNTL1_M1_MASK, freq->m1 - 1) |
+ FIELD_PREP(CLK_CNTL1_M2_MASK, freq->m2 - 1);
+ else
+ reg = FIELD_PREP(CLK_CNTL1_M1_MASK, freq->m1 - 1);
+
+ regmap_write(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL1, reg);
+
+ /* Enable clock */
+ regmap_update_bits(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0,
+ CLK_CNTL0_IN_GATE_EN, CLK_CNTL0_IN_GATE_EN);based on how I understand your code the *input* clock needs to be gated during rate change, so (in my opinion) it's fine to toggle it here.
+ + udelay(200); + + regmap_update_bits(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0, + CLK_CNTL0_OUT_GATE_EN, CLK_CNTL0_OUT_GATE_EN);
however, should we make the output clock configurable by implementing clk_ops.enable and clk_ops.disable?
+ + regmap_update_bits(cec_32k->regmap, AO_CRT_CLK_CNTL1, + CLK_CNTL1_SELECT_OSC, CLK_CNTL1_SELECT_OSC); + + /* Select 32k from XTAL */ + regmap_update_bits(cec_32k->regmap, + AO_RTI_PWR_CNTL_REG0, + PWR_CNTL_ALT_32K_SEL, + FIELD_PREP(PWR_CNTL_ALT_32K_SEL, 4));
is it correct to configure the muxes after enabling the clock output? also do you know about the other parents of PWR_CNTL_ALT_32K_SEL?
quoted hunk ↗ jump to hunk
+ + return 0; +} + +const struct clk_ops meson_aoclk_cec_32k_ops = { + .recalc_rate = aoclk_cec_32k_recalc_rate, + .round_rate = aoclk_cec_32k_round_rate, + .set_rate = aoclk_cec_32k_set_rate, +};diff --git a/drivers/clk/meson/gxbb-aoclk.c b/drivers/clk/meson/gxbb-aoclk.c index f61506c..6c161e0 100644 --- a/drivers/clk/meson/gxbb-aoclk.c +++ b/drivers/clk/meson/gxbb-aoclk.c@@ -59,6 +59,7 @@ #include <linux/mfd/syscon.h> #include <linux/regmap.h> #include <linux/init.h> +#include <linux/delay.h> #include <dt-bindings/clock/gxbb-aoclkc.h> #include <dt-bindings/reset/gxbb-aoclkc.h> #include "gxbb-aoclk.h"@@ -105,6 +106,17 @@ static int gxbb_aoclk_do_reset(struct reset_controller_dev *rcdev, GXBB_AO_GATE(uart2, 5); GXBB_AO_GATE(ir_blaster, 6); +static struct aoclk_cec_32k cec_32k_ao = { + .lock = &gxbb_aoclk_lock, + .hw.init = &(struct clk_init_data) { + .name = "cec_32k_ao", + .ops = &meson_aoclk_cec_32k_ops, + .parent_names = (const char *[]){ "xtal" }, + .num_parents = 1, + .flags = CLK_IGNORE_UNUSED, + }, +}; + static unsigned int gxbb_aoclk_reset[] = { [RESET_AO_REMOTE] = 16, [RESET_AO_I2C_MASTER] = 18,@@ -131,8 +143,9 @@ static int gxbb_aoclk_do_reset(struct reset_controller_dev *rcdev, [CLKID_AO_UART1] = &uart1_ao.hw, [CLKID_AO_UART2] = &uart2_ao.hw, [CLKID_AO_IR_BLASTER] = &ir_blaster_ao.hw, + [CLKID_AO_CEC_32K] = &cec_32k_ao.hw, }, - .num = ARRAY_SIZE(gxbb_aoclk_gate), + .num = 7, }; static int gxbb_aoclkc_probe(struct platform_device *pdev)@@ -172,6 +185,12 @@ static int gxbb_aoclkc_probe(struct platform_device *pdev) return ret; } + /* Specific clocks */ + cec_32k_ao.regmap = regmap; + ret = devm_clk_hw_register(dev, &cec_32k_ao.hw); + if (ret) + return ret; + return of_clk_add_hw_provider(dev->of_node, of_clk_hw_onecell_get, &gxbb_aoclk_onecell_data); }diff --git a/drivers/clk/meson/gxbb-aoclk.h b/drivers/clk/meson/gxbb-aoclk.h index 2e26108..e8604c8 100644 --- a/drivers/clk/meson/gxbb-aoclk.h +++ b/drivers/clk/meson/gxbb-aoclk.h@@ -9,7 +9,13 @@ #define __GXBB_AOCLKC_H /* AO Configuration Clock registers offsets */ +#define AO_RTI_PWR_CNTL_REG1 0x0c +#define AO_RTI_PWR_CNTL_REG0 0x10 #define AO_RTI_GEN_CNTL_REG0 0x40 +#define AO_OSCIN_CNTL 0x58 +#define AO_CRT_CLK_CNTL1 0x68 +#define AO_RTC_ALT_CLK_CNTL0 0x94 +#define AO_RTC_ALT_CLK_CNTL1 0x98 struct aoclk_gate_regmap { struct clk_hw hw;@@ -23,4 +29,14 @@ struct aoclk_gate_regmap { extern const struct clk_ops meson_aoclk_gate_regmap_ops; +struct aoclk_cec_32k { + struct clk_hw hw; + struct regmap *regmap; + spinlock_t *lock; +}; + +#define to_aoclk_cec_32k(_hw) container_of(_hw, struct aoclk_cec_32k, hw) + +extern const struct clk_ops meson_aoclk_cec_32k_ops; + #endif /* __GXBB_AOCLKC_H */ --1.9.1 _______________________________________________ linux-amlogic mailing list linux-amlogic at lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-amlogic