[v12,02/21] clk: Check that ops of composite clock components exist before calling

clk_composite_ops was shared between all devices in the composite clock
driver.  If one clock had a feature (such as supporting set_parent) which
another clock did not, it could call a null pointer dereference.

This patch does three things
1. It adds null-pointer checks to all composite clock functions.
2. It makes clk_composite_ops const and sets its functions at compile-time.
3. It adds some basic sanity checks to num_parents.

The combined effect of these changes is that any of mux, rate, or gate can
be NULL, and composite clocks will still function normally. Previously, at
least mux had to exist, since clk_composite_get_parent was used to
determine the parent for clk_register.

Signed-off-by: Sean Anderson <seanga2 at gmail.com>
Acked-by: Lukasz Majewski <lukma at denx.de>
---

Changes in v4:
- Return ENOTSUPP not ENOSYS with no set_parent

Changes in v3:
- Don't return an error code where a no-op would be fine

 drivers/clk/clk-composite.c | 57 +++++++++++++++++++++++--------------
 1 file changed, 35 insertions(+), 22 deletions(-)

Message ID	20200520191738.337845-3-seanga2@gmail.com
State	Superseded
Headers	show List-Id: U-Boot discussion <u-boot.lists.denx.de> From: seanga2 at gmail.com (Sean Anderson) Date: Wed, 20 May 2020 15:17:19 -0400 Subject: [PATCH v12 02/21] clk: Check that ops of composite clock components exist before calling In-Reply-To: <20200520191738.337845-1-seanga2@gmail.com> References: <20200520191738.337845-1-seanga2@gmail.com> Message-ID: <20200520191738.337845-3-seanga2@gmail.com>
Series	riscv: Add Sipeed Maix support \| expand [v12,00/21] riscv: Add Sipeed Maix support [v12,01/21] clk: Always use the supplied struct clk [v12,02/21] clk: Check that ops of composite clock components exist before calling [v12,03/21] clk: Unconditionally recursively en-/dis-able clocks [v12,04/21] clk: Fix clk_get_by_* handling of index [v12,05/21] clk: Add K210 pll support [v12,06/21] clk: Add a bypass clock for K210 [v12,07/21] clk: Add K210 clock support [v12,08/21] dm: Add support for simple-pm-bus [v12,09/21] dm: Fix error handling for dev_read_addr_ptr [v12,10/21] reset: Add generic reset driver [v12,11/21] lib: Always set errno in hcreate_r [v12,12/21] riscv: Add headers for asm/global_data.h [v12,13/21] riscv: Clear pending interrupts before enabling IPIs [v12,14/21] riscv: Clean up IPI initialization code [v12,15/21] riscv: Add option to support RISC-V privileged spec 1.9 [v12,16/21] riscv: Allow use of reset drivers [v12,17/21] riscv: Try to get cpu frequency from a "clocks" node if it exists [v12,18/21] riscv: Enable cpu clock if it is present [v12,19/21] riscv: Add device tree for K210 and Sipeed Maix BitM [v12,20/21] doc: riscv: Add documentation for Sipeed Maix Bit [v12,21/21] riscv: Add Sipeed Maix support

[v12,02/21] clk: Check that ops of composite clock components exist before calling

Commit Message

Patch