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path: root/drivers/clk/imx/clk-lpcg-scu.c
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2024-12-09clk: imx: lpcg-scu: SW workaround for errata (e10858)Peng Fan
[ Upstream commit 5ee063fac85656bea9cfe3570af147ba1701ba18 ] Back-to-back LPCG writes can be ignored by the LPCG register due to a HW bug. The writes need to be separated by at least 4 cycles of the gated clock. See https://www.nxp.com.cn/docs/en/errata/IMX8_1N94W.pdf The workaround is implemented as follows: 1. For clocks running greater than or equal to 24MHz, a read followed by the write will provide sufficient delay. 2. For clocks running below 24MHz, add a delay of 4 clock cylces after the write to the LPCG register. Fixes: 2f77296d3df9 ("clk: imx: add lpcg clock support") Signed-off-by: Peng Fan <peng.fan@nxp.com> Reviewed-by: Abel Vesa <abel.vesa@linaro.org> Link: https://lore.kernel.org/r/20241027-imx-clk-v1-v3-1-89152574d1d7@nxp.com Signed-off-by: Abel Vesa <abel.vesa@linaro.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-04-04clk: imx: Reference preceded by freeJian Dong
When register failed, clk will be freed, it will generate dangling pointer problem in later reference. it should return directly. Signed-off-by: Jian Dong <dongjian@yulong.com> Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
2020-10-26clk: imx: lpcg: add suspend/resume supportDong Aisheng
LPCG clock state may be lost when it's power domain is completely off during system suspend/resume and we need save and restore the state properly. Reviewed-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2020-10-26clk: imx: lpcg: allow lpcg clk to take device pointerDong Aisheng
Used to support runtime pm. Reviewed-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2020-10-26clk: imx: imx8qxp-lpcg: add parsing clocks from device treeDong Aisheng
One LPCG controller supports up to 8 clock outputs while each of them is fixed to 4 bits. It supports only gating function with fixed bits. So we can use the clk-indices to fetch the corresponding clock idx from device tree. With this way, we can write a generic LPCG clock drivers. This patch add that support to parse clocks from device tree. Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <kernel@pengutronix.de> Cc: Michael Turquette <mturquette@baylibre.com> Reviewed-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2020-08-22clk: imx: Explicitly include bits.hAnson Huang
It is better to explicitly include the required header file rather then get it through some recursive include. Signed-off-by: Anson Huang <Anson.Huang@nxp.com> Acked-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Shawn Guo <shawnguo@kernel.org>
2018-12-14clk: imx: add lpcg clock supportAisheng Dong
The Low-Power Clock Gate (LPCG) modules contain a local programming model to control the clock gates for the peripherals. An LPCG module is used to locally gate the clocks for the associated peripheral. And they're bedind the SCU clock. Cc: Stephen Boyd <sboyd@kernel.org> Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <kernel@pengutronix.de> Cc: Fabio Estevam <fabio.estevam@nxp.com> Cc: Michael Turquette <mturquette@baylibre.com> Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> Signed-off-by: Stephen Boyd <sboyd@kernel.org>