[PATCH 5.14 130/432] clk: imx8m: fix clock tree update of TF-A managed clocks

Greg Kroah-Hartman
2021-09-16T17:27:38Z

From: Ahmad Fatoum <a.fatoum@pengutronix.de>

[ Upstream commit d36207b848a6490e14664e2197a1c8ab51d8148e ]

On the i.MX8M*, the TF-A exposes a SiP (Silicon Provider) service
for DDR frequency scaling. The imx8m-ddrc-devfreq driver calls the
SiP and then does clk_set_parent on the DDR muxes to synchronize
the clock tree.

Since 936c383673b9 ("clk: imx: fix composite peripheral flags"),
these TF-A managed muxes have SET_PARENT_GATE set, which results
in imx8m-ddrc-devfreq's clk_set_parent after SiP failing with -EBUSY:

echo 25000000 > userspace/set_freq
imx8m-ddrc-devfreq 3d400000.memory-controller: failed to set
dram_apb parent: -16

Fix this by adding a new i.MX composite flag for firmware managed
clocks, which clears SET_PARENT_GATE.

This is safe to do, because updating the Linux clock tree to reflect
reality will always be glitch-free.

Fixes: 936c383673b9 ("clk: imx: fix composite peripheral flags")
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Link: https://lore.kernel.org/r/20210810151432.9228-1-a.fatoum@pengutronix.de
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clk/imx/clk-composite-8m.c | 3 ++-
drivers/clk/imx/clk-imx8mm.c | 7 ++++---
drivers/clk/imx/clk-imx8mn.c | 7 ++++---
drivers/clk/imx/clk-imx8mq.c | 7 ++++---
drivers/clk/imx/clk.h | 16 ++++++++++++++--
5 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/drivers/clk/imx/clk-composite-8m.c b/drivers/clk/imx/clk-composite-8m.c
index 2c309e3dc8e3..04e728538cef 100644
--- a/drivers/clk/imx/clk-composite-8m.c
+++ b/drivers/clk/imx/clk-composite-8m.c
@@ -216,7 +216,8 @@ struct clk_hw *imx8m_clk_hw_composite_flags(const char *name,
div->width = PCG_PREDIV_WIDTH;
divider_ops = &imx8m_clk_composite_divider_ops;
mux_ops = &clk_mux_ops;
- flags |= CLK_SET_PARENT_GATE;
+ if (!(composite_flags & IMX_COMPOSITE_FW_MANAGED))
+ flags |= CLK_SET_PARENT_GATE;
}

div->lock = &imx_ccm_lock;
diff --git a/drivers/clk/imx/clk-imx8mm.c b/drivers/clk/imx/clk-imx8mm.c
index ce7127ccddab..e92621fa8b9c 100644
--- a/drivers/clk/imx/clk-imx8mm.c
+++ b/drivers/clk/imx/clk-imx8mm.c
@@ -470,10 +470,11 @@ static int imx8mm_clocks_probe(struct platform_device *pdev)

/*
* DRAM clocks are manipulated from TF-A outside clock framework.
- * Mark with GET_RATE_NOCACHE to always read div value from hardware
+ * The fw_managed helper sets GET_RATE_NOCACHE and clears SET_PARENT_GATE
+ * as div value should always be read from hardware
*/
- hws[IMX8MM_CLK_DRAM_ALT] = __imx8m_clk_hw_composite("dram_alt", imx8mm_dram_alt_sels, base + 0xa000, CLK_GET_RATE_NOCACHE);
- hws[IMX8MM_CLK_DRAM_APB] = __imx8m_clk_hw_composite("dram_apb", imx8mm_dram_apb_sels, base + 0xa080, CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE);
+ hws[IMX8MM_CLK_DRAM_ALT] = imx8m_clk_hw_fw_managed_composite("dram_alt", imx8mm_dram_alt_sels, base + 0xa000);
+ hws[IMX8MM_CLK_DRAM_APB] = imx8m_clk_hw_fw_managed_composite_critical("dram_apb", imx8mm_dram_apb_sels, base + 0xa080);

/* IP */
hws[IMX8MM_CLK_VPU_G1] = imx8m_clk_hw_composite("vpu_g1", imx8mm_vpu_g1_sels, base + 0xa100);
diff --git a/drivers/clk/imx/clk-imx8mn.c b/drivers/clk/imx/clk-imx8mn.c
index 88f6630cd472..0a76f969b28b 100644
--- a/drivers/clk/imx/clk-imx8mn.c
+++ b/drivers/clk/imx/clk-imx8mn.c
@@ -453,10 +453,11 @@ static int imx8mn_clocks_probe(struct platform_device *pdev)

/*
* DRAM clocks are manipulated from TF-A outside clock framework.
- * Mark with GET_RATE_NOCACHE to always read div value from hardware
+ * The fw_managed helper sets GET_RATE_NOCACHE and clears SET_PARENT_GATE
+ * as div value should always be read from hardware
*/
- hws[IMX8MN_CLK_DRAM_ALT] = __imx8m_clk_hw_composite("dram_alt", imx8mn_dram_alt_sels, base + 0xa000, CLK_GET_RATE_NOCACHE);
- hws[IMX8MN_CLK_DRAM_APB] = __imx8m_clk_hw_composite("dram_apb", imx8mn_dram_apb_sels, base + 0xa080, CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE);
+ hws[IMX8MN_CLK_DRAM_ALT] = imx8m_clk_hw_fw_managed_composite("dram_alt", imx8mn_dram_alt_sels, base + 0xa000);
+ hws[IMX8MN_CLK_DRAM_APB] = imx8m_clk_hw_fw_managed_composite_critical("dram_apb", imx8mn_dram_apb_sels, base + 0xa080);

hws[IMX8MN_CLK_DISP_PIXEL] = imx8m_clk_hw_composite("disp_pixel", imx8mn_disp_pixel_sels, base + 0xa500);
hws[IMX8MN_CLK_SAI2] = imx8m_clk_hw_composite("sai2", imx8mn_sai2_sels, base + 0xa600);
diff --git a/drivers/clk/imx/clk-imx8mq.c b/drivers/clk/imx/clk-imx8mq.c
index c491bc9c61ce..83cc2b1c3294 100644
--- a/drivers/clk/imx/clk-imx8mq.c
+++ b/drivers/clk/imx/clk-imx8mq.c
@@ -449,11 +449,12 @@ static int imx8mq_clocks_probe(struct platform_device *pdev)

/*
* DRAM clocks are manipulated from TF-A outside clock framework.
- * Mark with GET_RATE_NOCACHE to always read div value from hardware
+ * The fw_managed helper sets GET_RATE_NOCACHE and clears SET_PARENT_GATE
+ * as div value should always be read from hardware
*/
hws[IMX8MQ_CLK_DRAM_CORE] = imx_clk_hw_mux2_flags("dram_core_clk", base + 0x9800, 24, 1, imx8mq_dram_core_sels, ARRAY_SIZE(imx8mq_dram_core_sels), CLK_IS_CRITICAL);
- hws[IMX8MQ_CLK_DRAM_ALT] = __imx8m_clk_hw_composite("dram_alt", imx8mq_dram_alt_sels, base + 0xa000, CLK_GET_RATE_NOCACHE);
- hws[IMX8MQ_CLK_DRAM_APB] = __imx8m_clk_hw_composite("dram_apb", imx8mq_dram_apb_sels, base + 0xa080, CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE);
+ hws[IMX8MQ_CLK_DRAM_ALT] = imx8m_clk_hw_fw_managed_composite("dram_alt", imx8mq_dram_alt_sels, base + 0xa000);
+ hws[IMX8MQ_CLK_DRAM_APB] = imx8m_clk_hw_fw_managed_composite_critical("dram_apb", imx8mq_dram_apb_sels, base + 0xa080);

/* IP */
hws[IMX8MQ_CLK_VPU_G1] = imx8m_clk_hw_composite("vpu_g1", imx8mq_vpu_g1_sels, base + 0xa100);
diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h
index 7571603bee23..e144f983fd8c 100644
--- a/drivers/clk/imx/clk.h
+++ b/drivers/clk/imx/clk.h
@@ -530,8 +530,9 @@ struct clk_hw *imx_clk_hw_cpu(const char *name, const char *parent_name,
struct clk *div, struct clk *mux, struct clk *pll,
struct clk *step);

-#define IMX_COMPOSITE_CORE BIT(0)
-#define IMX_COMPOSITE_BUS BIT(1)
+#define IMX_COMPOSITE_CORE BIT(0)
+#define IMX_COMPOSITE_BUS BIT(1)
+#define IMX_COMPOSITE_FW_MANAGED BIT(2)

struct clk_hw *imx8m_clk_hw_composite_flags(const char *name,
const char * const *parent_names,
@@ -567,6 +568,17 @@ struct clk_hw *imx8m_clk_hw_composite_flags(const char *name,
ARRAY_SIZE(parent_names), reg, 0, \
flags | CLK_SET_RATE_NO_REPARENT | CLK_OPS_PARENT_ENABLE)

+#define __imx8m_clk_hw_fw_managed_composite(name, parent_names, reg, flags) \
+ imx8m_clk_hw_composite_flags(name, parent_names, \
+ ARRAY_SIZE(parent_names), reg, IMX_COMPOSITE_FW_MANAGED, \
+ flags | CLK_GET_RATE_NOCACHE | CLK_SET_RATE_NO_REPARENT | CLK_OPS_PARENT_ENABLE)
+
+#define imx8m_clk_hw_fw_managed_composite(name, parent_names, reg) \
+ __imx8m_clk_hw_fw_managed_composite(name, parent_names, reg, 0)
+
+#define imx8m_clk_hw_fw_managed_composite_critical(name, parent_names, reg) \
+ __imx8m_clk_hw_fw_managed_composite(name, parent_names, reg, CLK_IS_CRITICAL)
+
#define __imx8m_clk_composite(name, parent_names, reg, flags) \
to_clk(__imx8m_clk_hw_composite(name, parent_names, reg, flags))

--
2.30.2